About ScienceofMom

I am a new mama to a baby girl, a former research scientist, and now a writer. I have a PhD in Nutrition and years of experience at the lab bench, but these days I spend my time trying to keep up with my almost-toddler. When she naps - I write.

SIDS and Bedsharing: A Pediatrician’s Perspective

Posted on May 23, 2013 by ScienceofMom

I’ve been thinking about bedsharing and sleep safety for the last few months. I have devoted an entire chapter of my book to this topic. Not only is it an important question for parents, but it’s an issue with so much complexity — wrinkles and folds of factors like breastfeeding, bonding, instinct, culture, and just plain reality.

I think it is vitally important to understand the relationship between bedsharing behavior and risk of SIDS and accidental deaths. But our ability to tease apart every factor that might impact sleep safety is imperfect; there will always be factors that aren’t quantified in these studies, not to mention the fact that case control studies have some inherent limitations. You’ve probably heard about the study published this week by Carpenter et al. in BMJ. It combines 5 historic case control data sets from Europe, the U.K., and Australasia to specifically look at the risk of bedsharing in breastfed babies in nonsmoking households. It concludes that bedsharing poses an increased risk of SIDS, even in these ideal situations. I think it’s an important study, but it also has some limitations and doesn’t answer all of our questions with certainty. In fact, no study will probably ever do that. (You can read some critiques of the Carpenter study here and here.)

But even if we accept that bedsharing increases a baby’s risk of dying unexpectedly during sleep, we still have to answer the bigger question of how we translate this information to families living in the real, difficult world of infant sleep. Many families value bedsharing as a cultural practice; others choose it because it feels right. Still others bedshare because it is the only way that anyone gets any sleep at night, and we all know that sleep deprivation carries some risk, too, as does falling asleep on a couch with your baby. This is the reality.

Pediatricians face this reality in their clinics every day, when they talk with parents of new babies about sleep. In my book, one of the questions I explore is how pediatricians handle this conversation, given that their professional organization, the American Academy of Pediatrics, recommends against bedsharing. Several months ago, I sent some questions to one of my favorite pediatrician bloggers, Dr. Melissa Arca of Confessions of a Dr. Mom. She had initially agreed to a Q&A, but then she didn’t respond with her answers. It was the height of the busy flu season, and I figured that she was just busy. Then, this week, she surprised me with her responses. She had been thinking about bedsharing given the news of this recent study, and she was inspired to restart this conversation. We’ve cross-posted our Q&A on both our blogs. Check out her post for more about her initial hesitancy to address these questions, and please feel free to share your experiences in the comments below.

Alice: How did sleep look for your two children?

Melissa: My first child was a challenge to say the least. He is the one who made me question the safety of bed-sharing in the first place. For the first 6 months of his life, sleep was virtually non-existent (or at least that’s the way it felt to me) because he needed my arms and constant soothing throughout the night. But I was terrified to bedshare. I was literally at the end of my sleep deprivation rope. I had tried everything. And instead of listening to my instincts, I was fighting them. Because I was scared.

I never envisioned myself as a bedsharing parent. As a pediatrician, I was adamantly against it. But it was exactly what my baby needed and we struggled and limped along until I finally realized that.

My second child was a breeze and that’s no lie. She was always (and still is) an “easy sleeper”. She needed her space and showed clear signs of being tired. When she was tired, that was it. I didn’t need to bedshare with her. She slept in her own bassinet next to our bed during her first few months of life before being transitioned to her own room.

They could not have been more different in the sleep department. Same parents. Same environment. Different children.

Alice: As a pediatrician, how did you feel about bedsharing before having children? Did becoming a mother change that?

Melissa: I didn’t think it was safe. At all. I had read the studies and the official recommendations. Back to sleep, crib and/or bassinet in the same room with no hazards such as loose bedding, pillows, etc.

I never thought in a million years I would have become a bedsharing parent. But kids don’t have our same agendas. They don’t read the books or the studies. And when it comes to sleep…nothing could be more variable. The only constant is that we all need it.

Alice: You’ve written on your blog about your decision to finally bedshare with your first child. What kind of responses did your receive from other pediatricians and parents to your posts?

Melissa: Most reactions have been…yeah, I’ve been there. Or…I had a baby like that too. But, I’ve received some criticism too. Honestly, I think it happens to more families than are willing to admit it. It’s still taboo, particularly in the medical field. With good reason, for sure; but I think we need to talk about it. We need to address the issue. Not simply say…don’t do it, it’s not safe.

This is not a one size fits all situation. There are so many factors at play. So from a practical standpoint, we need to be willing to hear parents out and meet them where they are.

Alice: Do you believe that bedsharing can be safe if practiced with care?

Melissa: I think it can be made “safer”. I still believe that the AAP recommendations against it and safe sleeping tips such as back to sleep, sleeping in a separate crib or bassinet but in the same room as parents, and the guidelines for keeping loose bedding, etc out of baby’s crib is the safety gold standard.

BUT…there are thousands of families who choose to bedshare and are committed to it. They will continue to do so in spite of recommendations against it. As a pediatrician and first time mom, I found myself at this very crossroad. For me, bedsharing was born out of sheer need…and a nagging instinct that I had been fighting. Still, it took me 6 months to finally feel good about doing it.

For bedsharing families I think we have a responsibility to discuss safety issues with them. We need to advise them the safest way to do so. There are so many variables involved when it comes to bedsharing that makes studying it and having safe bedsharing guidelines difficult from a public health perspective. That alone makes it inherently risky.

But it doesn’t mean that we shouldn’t try. We absolutely should. Removing some of the added risks that can go along with bedsharing (such as heavy blankets, other children, exposure to second-hand smoke etc.) will reduce the risk of SIDS and accidental suffocation. So we should be having these discussions.

We know that bedsharing can look very different from one family to the next. It can be absolutely dangerous for one infant but relatively safe for another. One thing parents should know is that bedsharing cannot be an afterthought nor an act of desperation…this is very dangerous. Safe bedsharing is really an overhaul of the whole sleep environment. You cannot simply take your baby and put him/her in your bed without any preparation. So parents really have to be committed to it and be willing to take the proper safety precautions.

Alternatively, exhausted parents who are too frightened to bedshare may fall asleep holding their babies in their arms on couches, chairs, or in their beds. You can imagine how dangerous that can be for an infant. Before I embarked on bedsharing, I found myself in these very situations.

Alice: The AAP recommends against bedsharing in their policy statement on prevention of SIDS/suffocation deaths. Do you think this recommendation is appropriate? Do you share the AAP recommendation with the families in your practice?

Melissa: Yes and I do share these recommendations with my families. But I also ask them what sleep looks like in their house. How is everyone sleeping? Where do they sleep? Does anyone smoke? Where do they want baby to sleep and have they taken the proper precautions to make sure baby’s sleep environment is as safe as possible?

This allows for a more open, honest, and insightful discussion on what’s really going on in the home instead of simply spouting off the way they should be doing things.

Alice: Do you find it difficult to reconcile the realities of infant sleep practices among your patients with the AAP’s recommendation? Do you feel that the AAP’s stance against bedsharing puts you in a tight place?

Melissa: Sometimes an awkward place, yes. I agree with the AAP but I don’t think it sheds light on the whole story. Families are dynamic, babies are ever changing, and no two are alike. There is no possible way to control for all the factors involved here. But we should be able to come up with universal safe sleep guidelines for ALL babies, not just the ones sleeping in cribs or bassinets.

Alice: Do you believe that bedsharing can be beneficial to babies and families? Are there disadvantages to bedsharing that you think parents should be aware of?

Melissa: Yes. If it works for the families and babies seem to be thriving, absolutely. But parents need to be happy with it, not resenting every second of it. Breastfeeding moms tell me how wonderful it is and that they get more sleep that way.

The disadvantages are the inherent risk factors. I really stress to parents that bedsharing is a sleep overhaul for everyone. In order to make it the safest possible and eliminate some of these added risks they need to be willing to make some dramatic changes in their own sleep environment since baby will be there with them.

Here’s what “safe bedsharing” looks like to me:

a firm mattress on the floor as the sleeping surface (eliminates fall and entrapment risks)
baby sleeps between mom and edge of bed without anyone else in the bed (no pets, siblings, or dad…I know, sorry)
no maternal smoking, alcohol, or sedating medications
no loose bedding or comforters
baby is always put on his/her back to sleep
ideally, this is a breastfeeding baby, and if parents can put off bedsharing until 4 months of age when the risk of SIDS goes way down that is ideal too.

Alice: Is there anything else you’d like to share about your experiences with infant sleep as a pediatrician or as a parent yourself?

Melissa: We need to remember that it’s not one size fits all. We really need to take into consideration each unique baby and the sleep needs of both the parents and the baby. However, safety should always be paramount and this is where things become murky. The evidence that we have so far is stacked against bedsharing (but again, I think there are just too many factors to control for). I don’t think we’ll ever get the sleep studies that we want or need.

So the bottom line for me is: stick to the AAP sleep recommendations. Bedside bassinets are great for proximity and ease of breastfeeding. However, if you find yourself (like me) with a baby who needed constant contact and/or you are committed to bedsharing, make sure you take the necessary precautions. Know the risks and know what you can do to minimize them.

And this is where we (as pediatricians and public health advocates) can really help these families. We need to be willing to discuss the issues surrounding bedsharing beyond the standard it’s not safe, so don’t do it. A chronically sleep deprived mom and/or parent is dangerous for babies too. I think we can really have a positive impact on all babies by addressing these particular safety issues head on. After all, we are working towards the same goal…bringing up healthy and happy babies.

Thank you, Melissa, for sharing your perspective as a pediatrician and parent.

What about you, dear readers? How do you feel about the safety of bedsharing? If you bedshare, do you discuss safety with your pediatrician? Where else do you go for advice on sleep safety?

Baby Meets World: A Conversation with the Author

Posted on May 22, 2013 by ScienceofMom

Yesterday, I posted an excerpt from Nicholas Day’s new book, Baby Meets World. If you missed it, check it out to learn how modern hunter-gatherer societies raise children, and how that task is supported by not just by hard-working mothers but the entire culture. It’s good stuff.

After reading his book, I had lots of questions for author Nicholas Day. Today, I bring you our conversation about his book and on the roles of science, culture, and instinct in parenting.

Alice: Becoming a parent changes all of us. What was it about your particular transition to fatherhood that made you want to research and write this book, to dive into the history and the science of parenting in a way that extended beyond your own reality of parenting?

Nicholas: In a way, I think it was the part of me that wasn’t changed that led to this book: I had stupid questions about babies in the same way I have stupid questions about everything else. (It’s a personality flaw.) I didn’t see why I had to think of babies as simply problems to be solved. Most baby books have what I think of as the leaky faucet approach: if your baby is dripping, we recommend this socket wrench. And there were many, many times when all I wanted was that socket wrench. But I also thought babies were interesting subjects all on their own. I wanted a book that acknowledged that. And I wanted a book that was wide-angled. The study of infancy is highly compartmentalized: the different disciplines don’t talk to each other. The few good books about babies tend to be highly focused: they look at babies through the lens of a cognitive scientist, say, or a developmental psychologist. But there are so many lenses out there! It seemed a shame to only see a baby as like this or like that. There’s so much left outside the frame. So this book tries to show readers the many different versions of a baby that people have seen—and still see today.

It’s strange. You wouldn’t think that babies would be an obscure subject: they are everywhere. (In our highly fertile neighborhood, I sometimes feel like Hitchcock’s The Birds is being reenacted—but this time with babies.) But they’ve been weirdly neglected. This is sort of hard to believe: any book about babies has to clear the high hurdle of being another damn book about babies. (Right? Like that’s what we need. Also, we totally need more diet books.) But I concluded that we really did need that. Babies are still strangers in our midst.

Alice: Your book focuses on four basic facts of infancy: “suck, smile, touch, toddle.” How did you choose these topics? Why not “eat, sleep, poop, cry,” for example?

Nicholas: I joke about this at the end of the book—that there’s so much going on in infancy I could easily have chosen spitting, shitting, screaming, sharing.

Part of why I went with these topics was that I actually wanted answers about them: I really wanted to know where a smile comes from and what a first smile might mean, for example. But I also thought these subjects had been overlooked. There’s been an enormous amount written on sleep, for very obvious reasons: any new parent is obsessed with sleep. But there’s very little written about smiling or walking. It’s the leaky faucet problem: because a smile can’t be fixed, no one writes about it.

Alice: Your book is not at all intended to be a parenting advice book. It fact, it reads at times like a history of bad parenting advice. There are examples of medical authorities being horribly wrong in the advice that they gave to parents (such as the idea that newborns and sick babies should have little contact with their parents, to prevent the spread of germs). In hindsight, we can say that these crazy ideas were based more on opinion and personal theories than on any data. But after doing your research, what do you think is the role of science and medicine in guiding parents today?

Nicholas: This is a very hard question—I struggle with it even after writing the book. (I also have a soon-to-be-published piece about this in Motherlode over at the Times, and I don’t want to scoop myself.) It may seem like a cop out to quote you here! But I want to anyway—and don’t you dare delete it out of modesty—because I think your “what evidence-based parenting means to me” post is very sensible and nuanced in a way that discussions of science in parenting rarely are. You write:

“It is an attempt to understand the questions as well as the answers. It isn’t a search for the One Right Way so much as it is a quest to understand the variation, complexity, and bias inherent to real life. After all, no scientist will tell you that their research has answered all the questions; instead, they know that every new experiment uncovers both new knowledge and new questions. To me, it is this spirit of curiosity that defines evidence-based parenting.”

That’s wonderfully restrained. I rarely see that sort of humility in how people talk about the role of science in guiding parents, and I think this blog is a model for how to write about science and parenting: cautiously, rigorously, with a keen eye for the limitations of the research and an awareness of the role of culture. And a distaste for ringing pronouncements.

[Alice is totally blushing now.]

Nicholas: I’d add a caveat to your statement that no scientist will tell you that their research has answered all the questions. This is true. But scientists are often so deeply immersed in their work that they lose perspective. That’s not a bad thing: if you study something, you’d better believe that it is important. But it means that they are highly unreliable guides to the overall terrain. If you ask a geologist to lead you out of the wilderness, you’re going to hear an awful lot about rocks.

Parenting is a dizzyingly complex ecosystem: reducing it to single variables and then pronouncing on their rightness or wrongness, their goodness or badness, is really, really hard. Something is always being left out. The science has never been better, as you say, and the new evidence-based parenting promises a lot: for many years we have been told that “science” says things that science doesn’t actually say—and finally people are pointing this out. But we should be cautious about how much we think we know; we should be less certain about our certainties.

The promise and peril of science is that it can convince us that some things we feel are wrong are actually right. The power to convince someone against his or her better judgment is an awesome power.

Alice: Sometimes I think that modern Western parents are uniquely worried about parenting. We don’t feel like we have a strong parenting culture to guide us, so we’re all struggling to define our own philosophies about raising children. After your research on parenting through history and across cultures, do you think we really have it harder? Or are we just another in a long line of generations of parents full of angst?

Nicholas: My rough answer to this is twofold:

1) Most Western parents have lives that are easier, materially speaking, so to counterbalance that we’ve decided to make parenting harder. I’m halfway serious: the angst expands to fill the available space. We’re also around our children less, so we worry more about getting the most out of the time we have.

2) We live in a fractured age: at no point in human history has anyone had as many parenting choices as we have now. I think a lot of those choices are actually the illusion of choice—that we’re more influenced by the dominant culture, and less free to discard it, than we might believe—but there are still many real choices every parent is faced with. In a way, that’s what this blog is about: you’re trying to sort through, in an evidence-based way, all these choices. And that’s why this blog is so useful: we’re all paralyzed by these choices. There are too many yogurt brands in the yogurt case.

As I write in the book, the point of a culture, in a way, is to hand down the right answer to everyone in it: this is how you raise a baby. Many of these right answers weren’t actually right, of course. (Colostrum is semen!) But that didn’t matter. They were the answer. They kept parents from going crazy.

For us moderns, that’s no longer the case. And sometimes that’s good: the accumulation of knowledge and perspective has been hugely beneficial. (We are now pretty sure that colostrum is not semen.) But it also means that it is now a lot easier to go crazy: there are so many choices—so many potentially right answers—out there.

If you trawl through the diaries of parents past, you can certainly find lots of anxiety, lots of dread. But I think the core uncertainty that marks contemporary parenting is relatively new. Before this point, it simply wasn’t possible. And I as write in the book, it is profoundly ironic: never has having a baby been less perilous than it is now.

Alice: Is there such a thing as instinct when it comes to raising children?

Nicholas: Only when it comes to screaming at them. (Kidding! Mostly!)

So over the years a lot of people have thought about that question, looked at the past, and answered: NO. Reading through the history of childhood, you come across very serious, very rigorous researchers whose response to the parents of the past is basically: OMG. WTF.

But I think there is. I think the parents of the past, as monstrous as they might seem, almost always had really good reasons for doing what they did. And I also think there are really good evolutionary reasons for the existence of parental instinct. That said, if you talk about the evolutionary roots of that instinct, you don’t necessarily end up in a good place. (See Sarah Hrdy’s work on the adaptive logic of infanticide.)

So I’d argue that we have a tremendously powerful instinct when it comes to raising children. But that instinct is highly malleable. My book traces, in part, the many ways that culture and science have bent and deformed that instinct. As you say up above, approximately a century ago the conventional wisdom was that touching your baby was dangerous and should be avoided. Can you imagine how that affected the parents of the time—how wracked, how inside-out they must have felt? If we have any sort of parental instinct, it is surely to touch—to hold, to squeeze—our children. Many parents surely did just that. But it is clear that many didn’t: they obeyed the authorities. They withheld their affection.

Even now it is heartbreaking to think about. And it suggests that our instinct for raising children, as powerful as it may be, may not always matter all that much.

Thank you to Nicholas for sharing his time and thoughts on these fascinating topics. Check out Baby Meets World to learn more about the culture and science of parenting. It’s a thought-provoking and entertaining read. I think you’ll enjoy it.

What do you think about our conversation? How do culture, science, and instinct come together in your parenting?

What Would the Kung Do? An Anthropological Perspective on Intensive Parenting

Posted on May 21, 2013 by ScienceofMom

I recently had the pleasure of reading Baby Meets World, a new book by Nicholas Day. (Full disclosure: I received a free review copy of this book.) Baby Meets World is a mix of history of parenting advice and modern, fascinating science about some of the most fundamental truths of infancy (as the subtitle states: “suck, smile, touch, toddle”). You may have seen the author’s recent blog on Slate, called How Babies Work. I liked the blog, but I like the book more. In a world of conflicting parenting advice, Day’s many examples of how wrong or just plain weird the expert advice has been through the ages is refreshing perspective. And even as this book describes the modern science of infancy – highlighting just how amazing babies are – it cautions us that we can’t understand babies, even in the most empirical way, without putting them in the context of the culture into which they are born.

Reading Baby Meets World led me to an email conversation with the author, which I’ll post on the blog tomorrow. He also offered to share an excerpt from the book with you. I chose an excerpt from the “Touch” section of the book – my favorite of the four sections. Since it comes near the end of this section, it requires a bit of an introduction to put it in context.

We know touch is important to babies, but Western parenting culture has had a complicated relationship with touch. Just a century ago, parents were barely allowed to visit their children in newborn nurseries or pediatric hospital wards. That history is now, thankfully, behind us, and skin-to-skin contact and baby wearing have become mainstream practices.

Part of the renewed interest in touch over the last fifty years has come from anthropological accounts of hunter-gatherer societies. We figure that maybe we have lost touch with our roots, that maybe we could re-learn the right way to parent from modern hunter-gatherer societies, who presumably parent the way we were meant to.

Day describes some of these modern hunter-gatherers, including the Kung of the Kalahari Desert. Kung infants are carried and held almost constantly. They are breastfed frequently, as often as every fifteen minutes. If they’re not being held by their mothers, they’re being passed around between community members, showered with kisses and constantly entertained. They’re hardly ever set down on the ground to move of their own accord; the Kung believe this impairs motor development.

I’ve read about the Kung before. They’re sometimes held up as an ideal for modern parents in the same conversation that chastises us for relying too much on gadgets like strollers and baby swings. But in this chapter, Day tells us how the culture of the Kung supports this kind of intensive parenting:

“The entire structure of a Kung community supports the (many) demands of Kung parenting. A Kung mother is virtually always around other adults, who take turns holding the child. The situation is the polar opposite of that of many American mothers, who can feel marooned on an island with no one but this ferret-like creature around.”

And this:

“Almost half the time a Kung infant cries out, he is comforted by someone who isn’t his mother or by his mother plus someone else. When the mother responds alone, other people offer to take the child later on. The Kung mother isn’t abandoned with a wailing infant. But despite this shared caretaking, the Kung, as Konner notes, “have often been misrepresented as having almost exclusive maternal care.”

In other words, the Kung practice what we might call intensive parenting, but the mother does not do this alone. She has lots of help. And this is where our excerpt picks up…

Excerpt from Chapter 13: “In Which Touch Gets Perhaps a Little Too Much Power” (from Baby Meets World by Nicholas Day)

It’s worth dwelling on the distinction between exclusive maternal care and alloparenting— the term for when someone who isn’t a parent acts as a parent, as the Kung do when they respond to any crying baby. If the most important messages to get across to a baby— love, security, commitment— are communicated through touch, then the obvious follow- up question is: does it matter who’s doing the touching? The parent or the alloparent?

From the perspective of attachment theory, all child rearing is aimed at the same end: the tight bond between mother and child. There aren’t multiple different strategies toward a successful outcome— there’s only that one. (Bowlby waffled on this a little bit but not much: his hypothetical caregiver was clearly a mother.) The mother is supposed to be doing the touching. This argument wades into the evolutionary past for evidence— the low fat content of human milk, for example, which required infants to nurse frequently, for which they needed a mother right there, all the time. In devising his theory, Bowlby cited the behavior of primates like gorillas and chimpanzees, for whom child care is exclusively maternal— no one else need apply.

But studies of hunter-gatherers like the Kung, the very people you’d expect to be closest to our deep past, have shown that caregiving by someone in addition to the mother is common, even if other people rarely supplant the mother as the primary attachment figure. The amount of alloparenting varies widely, but the existence of it is the rule, not the exception. And as scientists learned more about primates, Bowlby’s conclusions were undermined: fully half of all living primates do not provide exclusive maternal care.

As more research of hunter-gatherer cultures was published, a pattern emerged. For the Efe, who live in the northern Congolese rain forest, alloparenting is completely ordinary. Up until toddlerhood, an Efe infant rotates among multiple caregivers several times during a single hour; she nurses from multiple women.

Even when the mother is present, she isn’t necessarily the primary caregiver. Alloparenting is a cushion against the excruciatingly high mortality rates of the Efe: the more alloparents an infant has at a year old, the more likely she is to still be alive at age three.

Among traditional societies that are not hunter-gatherers, alloparenting is no less unusual. In West Africa, Beng mothers return to physical labor in the fields when their infant is only a couple of months old. How do they manage this? They hire someone in the village, often a young girl, to carry the child for part of each day. But because such a girl is usually only available part time, any Beng mother has a long list of sitters who can fill in. “Given frequent changes of caretaker,” writes the anthropologist Alma Gottlieb, who lived with the Beng, “it was not rare for a mother to be unaware of where her baby was, and in whose care, at some points in a typical day.” According to Gottlieb:

“A mother may hand her baby to her first- morning baby holder knowing that the latter is likely to pass the baby to another person if she herself becomes tired or if the baby fusses or if another person requests the child. By the time the infant is brought back to the mother to breast- feed—depending on the child’s age, this might be up to a few hours later— the little one may have been passed around to several people as caretakers. The mother may not even hear the full list of who was taking care of her child during this period.”

What do we make of all this extra-maternal care? The psychologist Edward Tronick, who has studied the Efe, argues that the whole idea of a “living” evolutionary past is a fiction. There isn’t a more “natural” way of life, Tronick says. “Biology is no more the destiny of the Efe than it is for us.” Instead, he says, the Efe philosophy of child care is just an adaptation for their environment: “These adaptations are neither more nor less biologically based than those of other cultures. That is, the Efe lifestyle is no more or less genetically based than the lifestyles of other peoples.”

For Tronick, there isn’t an answer to the question, How are we meant to take care of our children? There are many answers.

“Our decisions about child care practices are really decisions about cultural values: about what we want our children to become.”

The Kung aren’t a time capsule of Homo sapiens parenting. They’re a time capsule of parenting in the Kalahari Desert. If you are in search of parental wisdom, this is bound to be disappointing. It is extremely unlikely, after all, that you too live in the Kalahari Desert. A few academics have written that the longing for the “original” mode of parenting is a parochial, patronizing idea— it insults the complexity of the age- old cultures that it claims to venerate.

That’s true, of course. But there’s a less academic, more boring objection, too: we don’t live in the Kalahari Desert. Or the Amazon. Or the Congolese rain forest.

Margaret Mead’s hope— that the many cultural variations in child rearing would be a tool kit for Western parents to use— suffers what might be called the Kalahari Desert problem: the fact that all those variations evolved in their own cultural context.

Outside of that context, they’re meaningless or dysfunctional or worse; at a minimum, they’re frustrating. It’s puzzling that Mead of all people convinced herself otherwise: when it came to child rearing, she was a cultural anthropologist who somehow forgot about culture.

In this omission, she was way ahead of her time: many decades later, culture is what always gets erased from the practicalities of parenting. No parent tries to emulate hunter-gatherer societies in any other sphere of life: for sustenance, we do not go foraging instead of grocery shopping. But with our children, we start from the premise that all things are possible and that parenthood is the only relevant fact in the world, the shared experience that overrides all differences. Our child allows us access to the Amazonian within. But the choose-your-own-culture version of parenting has a stubborn problem: no parent is a culture.

Nicholas Day’s book on the science and history of infancy, Baby Meets World, was just published. His website is nicholasday.net. He is @nicksday on Twitter.

Do these examples of shared caregiving in modern hunter-gatherer societies surprise you? What can we learn from them? Do your children have “alloparents” – other adults that contribute to their care?

Sleep Deprivation: The Dark Side of Parenting

Posted on May 14, 2013 by ScienceofMom

Sleep deprivation is an inevitable part of having a baby, and surely that’s been true throughout the history of our species. But we also live in a culture that seems to take some amount of pride in getting by on little sleep. We think of sleep as time wasted, as lost productivity. We forget – or ignore – the biological necessity of sleep.

Becoming a parent only further stretches our already-too-thin sleep allotments. Newborn babies wake frequently to feed or for comfort during the night. We try to “sleep when the baby sleeps” and piece it together to come up with a reasonable amount, but it often doesn’t feel sufficient. And now more than ever, new parents are really isolated as they make this transition; they don’t have much in the way of backup resources to help with the 24/7 job of caring for a baby.

This month, the theme of our Carnival of Evidence-Based Parenting is Transition to Parenthood. (See the bottom of this post for links to other Carnival posts and here for summaries of them all.) Sleep deprivation is a universal part of that transition. What does the sleep deprivation of early parenthood really look like? How does it affect us? And what can we do to mitigate it?

Just How Bad Is It?

For many moms, sleep debt actually begins in pregnancy, when sleep needs may increase but discomfort and frequent trips to the bathroom interfere with a full night’s sleep. But by far, the biggest change happens in the immediate postpartum period. One study found that in the first week of the baby’s life (compared with late pregnancy), moms got 1.5 hours less sleep, fragmented into three times more sleep episodes per day. The early postpartum period is also characterized by lots of day-to-day variability in sleep. Sleeping with a new baby means unpredictability, with little to no control over whether tonight will be a good night or a bad one.

Mothers usually get the majority of our sympathy when it comes to postpartum sleep deprivation, but the research shows that fathers’ sleep takes a hit, too. A study of 72 San Francisco couples welcoming their first baby compared sleep in the last month of pregnancy to sleep in the first month postpartum (around 20 days of life). Across this time span, mothers lost an average of 41 minutes of nighttime sleep, while dads lost just 18 minutes. Moms, however, gained 30 minutes per day in daytime napping; dads didn’t get a nap bump at all. In fact, in this study, dads actually slept less than moms – both in late pregnancy and in the postpartum period. Moms still had it harder; they were waking more during the night and had more sleep fragmentation than dads (and it’s quite possible that moms need more sleep, what with recovery from childbirth and the demands of breastfeeding). But regardless, in this and other studies, moms and dads both reported a similar level of fatigue during the day.

There’s some good news to come out of this research, however. It seems that experienced moms are better at handling sleep in the postpartum period. Despite juggling more responsibility at home, studies show that moms who had given birth at least once before tended to get more sleep at all stages of pregnancy and in the postpartum period. Their sleep was also more efficient, meaning that of the time they spend in bed, they spend most of it sleeping rather than tossing and turning – or laying awake listening to the grunts and sighs of new baby sleep. Somehow, experienced moms seem to prioritize sleep more, or they’re just so tired that they crash hard at every opportunity.

How does sleep deprivation affect new parents?

We know a lot about the effects of sleep deprivation but actually very little about the specific type of crap sleep experienced by new parents. Most sleep deprivation studies have been conducted in residential labs, where participants (often young, probably resilient, undergrads) are generally paid to live for a few nights or maybe weeks so that their sleep habits can be controlled and monitored. In a review paper entitled “Sleep Disruption and Decline in Marital Satisfaction Across the Transition to Parenthood,” Gonzaga professor Anna Marie Medina and colleagues make an important point: Lab study participants know that they’ll be subjected to sleep deprivation for a finite amount of time, and they know they can even drop out if it becomes too much for them.

“Understanding that one can end a study, and being certain of the temporal parameters of potential sleep deprivation, imbues the experience of sleep loss with a level of controllability that new parents seldom have. That is, (most) new parents realize they cannot opt out of the sleep disruption experience, and they have no certainty about when they may have an opportunity for sufficient sleep. The stress literature has suggested that such uncontrollability could amplify the mood and physiological consequences of sleep deprivation.”

In other words, most of what we know about the effects of lost sleep may be even worse in new parents. On that happy note, there are a few major areas of concern…

Sleep deprivation impacts mood.

Medical residents are notorious for being sleep-deprived, and their situations may be similar to new parents in that their sleep is chronically restricted and fragmented. Studies on medical residents show that sleep loss is associated with more intense negative emotions and hostility. One study found that interns who became chronically sleep-deprived over the course of their first year of training had seven times the odds of becoming moderately depressed, compared to those managing to get enough sleep. Reading these studies, all I could feel was sympathy for my friends who juggled residency and new parenthood at the same time.

Specific to new moms, many studies show that moms whose babies have sleep problems are at greater risk for postpartum depression. In studies that have given parents advice in managing their baby’s sleep, resulting in improved sleep for the baby, maternal mood improves as well.

Sleep deprivation impacts cognitive function.

Sleep deprivation decreases a range of cognitive abilities, and I’m not just talking about SAT scores. For example, reaction time and alertness are essential for safe driving. Working memory is the ability to juggle multiple tasks, and well, that’s what parents do. Cognitive flexibility is what allows you to see a situation from more than one point of view (a skill vital to both parenting a toddler and maintaining a healthy marriage) or to quickly switch tasks, maybe from trying to fire off a work email to the more urgent demands of a toddler who has to go potty NOW. Verbal fluency is the ability to find the right word at the right time – to communicate effectively. We use all of these skills throughout our daily lives. They allow us to work towards goals (even mundane ones like getting out the door or getting dinner on the table), solve problems, and regulate emotions. And guess what? All of these cognitive skills are impaired by sleep deprivation.

To put this into perspective, one study found that two weeks of six hours of sleep per night caused declines in many cognitive measures – similar to those found after a full 24-48 hours of sleep deprivation. Perhaps more concerning is that the six-hour sleepers had no idea how impaired they were; they rated their sleepiness as only mild, but their test performance showed otherwise. Another study found that cognitive performance of people who had been awake for 18-19 hours was comparable to those with blood alcohol content (BAC) of 0.10 (the legal limit for driving in most U.S. states is 0.08). It is estimated that 15-33% of fatal car crashes are related to driver fatigue.

What can you do to improve your sleep situation?

I know that you know that sleep deprivation sucks, and I don’t mean for this post to be a downer. Is there anything we can we do to make things better? I can’t claim to have answers, but I’ll offer some suggestions:

Cut yourself some slack. This parenting job is hard enough as it is. Doing it on little sleep everyday? It’s a hurculean task, and yet we do it. Sometimes we need to just focus on the basics and have popcorn for dinner.

Prioritize sleep. It’s so critical to our health and happiness. The dishes in the sink? They aren’t nearly as important.

Give yourself a bedtime. We know our kids don’t function well if they’re short on sleep. We don’t either – we’re just a little better at hiding it.

Get help. This is particularly critical for parents of newborns. It may require creative delegation of tasks to friends and family so that you can squeeze in a longer nap or an earlier bedtime. They’re happy to help, and you need it. We were never meant to parent alone.

Help your baby develop healthy sleep patterns. Check out my tips for newborn sleep here. And if your older baby is struggling with sleep (and by extension, you are too), know that it is not selfish to make changes that help everyone get the rest they need (more on that here).

Avoid screen time before bed. It gets in the way of melatonin release, confusing the biological clock trying to keep time in our brains and prepare us for sleep. Yes, your Facebook feed may be your lifeline to the world, but it could also be keeping you up at night.

Be aware of your sleep debt. I think that after a while, we forget how much sleep we’re missing. Six hours a night and chronic daytime yawns become our new normal. But knowing that we’re behind on sleep, combined with the knowledge of the profound effects of sleep debt on mood and cognition, can give us valuable perspective. Maybe, for example, your partner is being just a little bit of an ass instead of the complete asshole that you perceive. Maybe catching up on sleep will help the day’s problems seem a little more manageable.

And now, a confession: All of these tips I just gave you? I’m not very good at them. I hate leaving dishes in the sink, and I’m not good at asking for help. I stay up too late – usually in front of my computer. I don’t get enough sleep, and it isn’t even my daughter’s fault. She sleeps for 11 hours at night. Why can’t I manage to sleep for 8 of those? What am I staying up for? It’s that treasured ME time. These days, most of it is actually spent working, but that doesn’t make it easier for me to give any of it up. This research, though, has convinced me that sleep deprivation is probably putting a damper on my productivity, and maybe my parenting patience.

So, I’m taking a pledge: For the rest of the month of May, in honor of Mothers’ Day, I’m giving myself at least 7 hours of sleep each night. I’m making it a priority. I’m informing my husband that no, I will not watch one more episode of Breaking Bad with him, unless it is before 10 PM. And I’m turning off my computer and phone by that time, too. It’s a personal experiment and a gift to myself. Happy Mother’s Day, Me!

Do you get enough sleep? If so, how do you do it? If not, what’s standing in your way?

Check out the other posts in this second edition of the Carnival of Evidence-Based Parenting:

The Transition to New Motherhood (Momma, PhD)

Bonding in Early Motherhood: When Angels Don’t Sing and the Earth Doesn’t Stand Still (Red Wine and Applesauce)

The Connection Between Poor Labour, Analgesia, and PTSD (The Adequate Mother)

For Love or Money: What Makes Men Ready for New Fatherhood (Matt Shipman)

What the Science Says (and Doesn’t Say) About Breastfeeding Issues, Postpartum Adjustment, and Bonding (Fearless Formula Feeder)

No, Swaddling Will Not Kill Your Baby (Melinda Wenner Moyer, Slate)

Sleep Deprivation: The Dark Side of Parenting (Science of Mom)

The Parenting Media and You (Momma Data)

Reassessing Happiness Research: Are New Parents Really That Miserable? (Jessica Smock)

40 Long Days and Nights (Six Forty Nine)

You can also “like” the Carnival of Evidence-Based Parenting on Facebook. Check out our Facebook page, and connect with all of us there! And finally, we’ll be hosting a Twitter party (I’m @scienceofmom) Friday 1-2 PM EST to discuss new parenthood and our posts (#parentscience). Please join us!

6 Tips for Sweet Newborn Sleep

Posted on May 9, 2013 by ScienceofMom

Nothing can prepare you for the changes in your sleep when you welcome a newborn baby into your family. Experienced parents will issue dire warnings and tell you to sleep while you can during the last few weeks of pregnancy. (And you will think, yeah right, there’s a large boulder resting on my bladder, and sometimes it kicks for good measure.)

But then the baby arrives, and your world changes forever. Sleep disruption is one of the most immediate and dramatic changes associated with parenthood. It isn’t just that you’re getting less sleep; it’s that your sleep is suddenly dependent on this baby sleeping. And even though newborns sleep a lot – as much as 16-18 hours per day – it feels disorganized and unpredictable.

The thing is, babies, even brand new ones, actually do have organized sleep, it just isn’t organized like yours. But under the surface, baby is working towards being more like you in his sleep. During the first few months, you have no choice but to go with the flow and sleep when the baby sleeps (something I was never good at), but it can help to understand the inherent patterns in your baby’s sleep/wake cycles so that they become more predictable. Your goal is to work with your baby’s biology, find some time for your own sleep, and support your baby in his natural development towards more mature sleep patterns.

In the research for my book, I’ve buried myself in research papers on infant sleep, trying to glean some knowledge that can be helpful to parents in these first few months of baby’s life. Here’s what I’ve come up with so far:

1. Understand newborn sleep cycles. Newborn sleep alternates between active and quiet sleep (akin to REM and non-REM sleep in adults). During the first few months of life, infants usually begin each sleep period in active sleep. Then, after about 25 minutes, they’ll transition to a cycle of quiet sleep, also about 25 minutes long. During active sleep, babies will twitch and flail their limbs, grunt and sigh, and maybe even cry a little. Their eyes move beneath translucent closed lids and may even open from time to time. In quiet sleep, babies breathe slowly and rhythmically, and their bodies are still ^1,2.

Why care about the biology of sleep? Because it can help you in these practical ways:

Babies wake easily from active sleep, so if your baby falls asleep in your arms, wait until you see signs of that deeper, quiet sleep before you try to move him.
Around the 45-50 minutes mark, baby will be finishing up that first active/quiet sleep cycle of 45-50 minutes. Transitioning from one cycle to the next can be tricky for a new baby, so if he wakes during this time (particularly if it’s after just one cycle), see if he wants your help returning to sleep before assuming that he’s ready to eat or play.
Active sleep is noisy. Parents often mistake the normal vocalizations of active sleep as the baby waking, and in their efforts to soothe the baby, they’ll actually wake him up. If you think your baby is waking up, pause and watch him for a moment. He may just be dancing in his sleep, or he might be waking briefly only to return to sleep on his own.

2. Help your baby find a rhythm. We are adapted to Earth’s 24-hour cycle of light and dark, and our physiological circadian rhythms help us to feel awake during the day and sleepy at night. Newborn babies, on the other hand, sleep just as much during the day as they do at night. It takes them some time to develop rhythms to match our day/night cycle. You can help by sending baby strong environmental and social cues about day and night.

During the day, keep the baby in a light, maybe even noisy place, even as he naps. At night, keep the lights as low as possible and the environment quiet. Even as you’re feeding frequently during the night (and you probably are), keep your interactions with your baby very quiet, uninteresting, and unstimulating. Be boring. With these cues, babies start to show physiological circadian rhythms quickly. A rhythm in body temperature can be detected around one week of age, and by two months of age, babies have robust rhythms of the hormones melatonin and cortisol. By two to three months, most babies are sleeping for most of the night (just waking briefly to feed) and have some distinct periods of wakefulness during the day (with some naps, of course)^3–6. One study reported an outlier – a baby that hadn’t developed a day/night circadian rhythm at five months. Turns out that night owl took his night feedings in a brightly lit room – he had received confusing signals about nighttime⁷.

3. Start to develop a soothing bedtime routine. It’s never too early for this. Find some calming rituals that you repeat each night before bed. These become part of the social cues that will key your baby into the nighttime rhythm and let her know that sleep time is coming. Tell your baby what is happening: It’s almost time for bed, so we’re having a bath. Then you’ll have some milk, and I’ll sing our bedtime song. And then it will be time to sleep. (Bedtime routines have been shown to help babies fall asleep faster and get more sleep during the night, but they’ve only been empirically tested in older infants⁸. I just think it’s smart to start this within the first few months.)

4. If you’re breastfeeding, breastfeed at night. During pregnancy, baby was exposed to mom’s day/night rhythm of melatonin, which increases during the dark night and decreases during the light of day. If you breastfeed, you keep sending that sleepy melatonin signal to your baby through your milk, even before he begins to produce his own melatonin. Human breast milk reflects maternal plasma melatonin concentrations, peaking between midnight and 4 AM and being virtually undetectable during the day^9–11. Melatonin during a night feeding should help baby transition peacefully back to sleep. Consider this if you supplement with formula or use pumped breast milk for a nighttime bottle. Nighttime breast milk (pumped or from the breast) might mean better sleep for baby.

5. Let your baby practice falling asleep in different ways. You’re going to want to hold him a lot, and so will all his doting family. There is nothing like watching a newborn fall asleep in your arms. He’ll also fall asleep feeding. You might enjoy having him sleep on your chest in a wrap or sling while you go about your day. Enjoy all of these snuggles with your baby. But every once in a while, see if you can put him down sleepy but awake. Some, but not all, babies can be surprisingly flexible during the first months of life about how they sleep. Letting him practice this now may give your baby the skills he needs to sleep well later. Babies that are able to fall asleep without a lot of active soothing (i.e. feeding, rocking, bouncing, walking, driving) tend to be the same babies who sleep well during the night¹². This is a great time to encourage flexibility while also providing secure and predictable routines.

6. Observe your baby. Observing your baby means learning his particular signals for when he’s feeling sleepy; then you can work together towards getting comfortable for sleep. Observing your baby may mean that when you hear him start to grunt and move around during the night, you wait a moment and watch to see what he’s doing and if he’s trying to communicate with you. Is he hungry? Uncomfortable? Wet? He’ll let you know that. But he may just be transitioning from one sleep cycle to the next. He may want to go right back to sleep, or he may not have woken at all but instead is in a noisy active sleep period. Babies that learn to transition between sleep cycles without your help will grow into better sleepers later in infancy, but you have to give them a chance to practice this valuable skill^12–14. Wait a moment or two to see if he needs your help, and if he does, soothe him quietly.

What advice do you have for helping babies and parents find their groove with sleep?

REFERENCES:

1. De Weerd, A. W. & van den Bossche, R. A. S. The development of sleep during the first months of life. Sleep Med. Rev. 7, 179–191 (2003).

2. Anders, T., F. in Encycl. Early Child. Dev. (Tremblay, R. E., Boivin, M. & Peters, Rd.) 1–8 (Centre of Excellence for Early Childhood Development and Strategic Knowledge Cluster on Early Child Development, 2010). at

3. McGraw, K., Hoffman, R., Harker, C. & Herman, J. H. The Development of Circadian Rhythms in a Human Infant. Sleep 22, 303–310 (1999).

4. Mirmiran, M., Maas, Y. G. . & Ariagno, R. L. Development of fetal and neonatal sleep and circadian rhythms. Sleep Med. Rev. 7, 321–334 (2003).

5. Custodio, R. J. et al. The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin-pair synchrony. Clin. Endocrinol. (Oxf.) 66, 192–197 (2007).

6. Ardura, J., Gutierrez, R., Andres, J. & Agapito, T. Emergence and Evolution of the Circadian Rhythm of Melatonin in Children. Horm. Res. 59, 66–72 (2003).

7. McMillen, I. C., Kok, J. S. M., Adamson, M., Deayton, J. & Nowak, R. Development of Circadian Sleep-Wake Rhythms in Preterm and Full-Term Infants. Pediatr. Res. 29, 381–384 (1991).

8. Mindell, J. A., Telofski, L. S., Wiegand, B. & Kurtz, E. S. A nightly bedtime routine: impact on sleep in young children and maternal mood. Sleep 32, 599–606 (2009).

9. Illnerová, H., Buresová, M. & Presl, J. Melatonin rhythm in human milk. J. Clin. Endocrinol. Metab. 77, 838–841 (1993).

10. Cubero, J. et al. The circadian rhythm of tryptophan in breast milk affects the rhythms of 6-sulfatoxymelatonin and sleep in newborn. Neuro Endocrinol. Lett. 26, 657–661 (2005).

11. Cohen Engler, A., Hadash, A., Shehadeh, N. & Pillar, G. Breastfeeding may improve nocturnal sleep and reduce infantile colic: Potential role of breast milk melatonin. Eur. J. Pediatr. 171, 729–732 (2011).

12. Burnham, M. M., Goodlin-Jones, B. L., Gaylor, E. E. & Anders, T. F. Nighttime sleep-wake patterns and self-soothing from birth to one year of age: a longitudinal intervention study. J Child Psychol Psychiatry 43, 713–25 (2002).

13. Pinilla, T. & Birch, L. L. Help me make it through the night: behavioral entrainment of breast-fed infants’ sleep patterns. Pediatrics 91, 436–44 (1993).

14. Wolfson, A., Lacks, P. & Futterman, A. Effects of parent training on infant sleeping patterns, parents’ stress, and perceived parental competence. J Consult Clin Psychol 60, 41–8 (1992).

Breastfeeding a Toddler? Should You Be Concerned About Iron Deficiency?

Posted on April 22, 2013 by ScienceofMom

You may have heard about a study published in Pediatrics last week (Maguire et al. 2013) showing an association between iron deficiency and breastfeeding beyond a year. If you’re breastfeeding a toddler, or considering it, you might be wondering if you should be worried about iron deficiency. There is very little research on breastfeeding beyond a year in developed countries, so this study is worth a closer look. (If you’re interested, I’ve written before about some of that research, my own reasons for choosing to breastfeed beyond a year, and my experience of weaning my two-year-old.)

What This Study Shows

This was a cross-sectional study of children ages 1-6 in Toronto, Canada. Blood samples were taken from 1647 children, and their mothers were asked, “How long has your child been breastfed?” We always have to be cautious about studies based on parental recall. However, research shows that mothers actually answer this question with good accuracy (Li et al. 2005). Of the children in this study, 93% had been breastfed at all, and median breastfeeding duration was 10 months. Twenty-seven percent of children were breastfed for more than one year, and 4% breastfed for more than two years.

The children’s blood samples were analyzed for serum ferritin and hemoglobin. Serum ferritin reflects the amount of iron stores available for use by the body, so it can be used to assess iron deficiency. If an iron deficient child also had low hemoglobin, he was diagnosed as having iron deficiency anemia. In this study, the prevalence of iron deficiency was about 9%, and 1.5% had iron deficiency anemia, findings similar to other studies in developed countries (Baker et al. 2010, full text here).

This study showed that kids that were breastfed for longer were more likely to be iron-deficient. Each month of breastfeeding beyond baby’s first birthday increased the risk of iron deficiency by about 5%. Children who were breastfed for longer than a year were estimated to have 1.7 times the odds of being iron deficient than those breastfed for less than a year. The researchers corrected for several potentially confounding factors: age, gender, birth weight, BMI, ethnicity, household income, day-care attendance, age of introduction of solids and cow’s milk, and current daily intake of cow’s milk. Children with iron deficiency were also more likely to be heavier at birth (bigger babies have higher iron requirements), younger (meaning that older kids seemed to have recovered from iron deficiency), and to be drinking more cow’s milk (something I wrote about here). Breastfeeding duration was not associated with iron deficiency anemia, which would indicate a more severe deficiency.

An obvious limitation to this study was that the observed relationship between breastfeeding and iron deficiency was just a correlation. There are other factors that could come into play that weren’t examined, like timing of umbilical cord clamping and how much iron these kids were getting from their diets or supplements. For example, it’s possible that moms who breastfeed longer are less likely to give their toddlers a multivitamin or other iron supplement. It that case, it wouldn’t be the breastfeeding that increased the risk of iron deficiency, but rather something else about moms who choose to breastfeed beyond a year. This is a major limitation, but to be fair, almost every study that shows positive outcomes for breastfeeding has the same problem.

Why be concerned about iron deficiency?

Iron is a mineral essential to life in all animals. Most of the iron in the body is used to make hemoglobin and myoglobin, so iron is really critical for oxygen transport to all tissues of the body. Iron is also part of several enzymes involved in energy metabolism. Every cell in the body requires iron, but blood, brain, and muscle cells are the ones that really suffer if there isn’t enough iron around. A person with severe iron deficiency will develop iron deficiency anemia, one of several types of anemia.

Iron deficiency in the first years of life, even without anemia, has been associated with cognitive, motor, and behavioral deficits (Lozoff et al. 2006). There are a lot of confounding variables in these studies, because kids that are iron deficient are likely to have other disadvantages as well. However, there are mechanisms for a causal relationship established through animal research (McCann and Ames 2007). So there’s some controversy as to just how scared we should be about iron deficiency, but given that we’re talking about brain development of our kids and that iron deficiency can be corrected with dietary changes, I think we should pay attention to it.

The current study was the first to look at the relationship between breastfeeding and iron in toddlers. Many studies have shown that exclusively breastfed babies are at higher risk for iron deficiency during late infancy (reviewed by Baker et al. 2010, full text here). Human breast milk is low in iron, but babies are usually born with enough iron, passed from mom via the placenta, to last for about the first six months. Delayed cord clamping at birth can extend the iron stores by another month or two. If breastfed babies aren’t getting some good iron-rich solid foods by late infancy, they can become iron-deficient.

So should I be worried about my breastfed toddler?

Worried? I wouldn’t go that far. Instead, I’d say you should be alert to the possibility that your breastfed toddler could become iron deficient. The good news is that it isn’t that hard to prevent iron deficiency if you’re mindful about nutrition.

How can I ensure that my breastfeeding toddler is getting enough iron?

Why would a breastfed toddler be at greater risk for iron deficiency? The study at hand doesn’t tell us, but I’ll speculate for you. Breast milk doesn’t have much iron. Yes, the iron in breast milk is well-absorbed, but there is still very little there. That’s probably a good thing for an infant (more on that here), but it means that breast milk really can’t provide complete nutrition for a growing toddler. Toddlers need good iron-rich sources of solid foods in their diets. If a toddler fills up on breast milk, then it may be challenging for him to get balanced nutrition.

So how can you make breast milk part of a balanced diet for a toddler?

Talk with a health care provider about your child’s risk for iron deficiency. Consider having him tested so that you know if you should be concerned. If he does test low for iron, then depending on the severity, your pediatrician might recommend a supplement or suggest trying to correct the problem through diet.

Include lots of iron-rich foods in your toddler’s diet, like meats, legumes, whole grains, green veggies, and dried fruits. Of course, toddlers can be picky, so this may be easier said than done. Know that it may take many low-pressure exposures for your kid to be ready to try new foods. Iron-fortified breakfast cereals are a good option for more skeptical eaters. You can find a list of iron-rich foods, as well as strategies for increasing iron absorption, in this post.

Cow’s milk inhibits iron absorption. If your toddler is breastfeeding AND drinking cow’s milk, consider limiting cow’s milk to just one or two cups per day (or even none at all). Of course, without cow’s milk, you’re losing a good source of vitamin D (also low in breast milk), so you may want to consider a vitamin D supplement.

Evaluate if breastfeeding is getting in the way of your toddler eating well at meals. This might be an issue if you’re breastfeeding on demand throughout the day. Toddlers do better with eating if they have structure around their meals and snacks. To you and your toddler, breast milk is probably much more than a food. It is comfort, closeness, and a moment of quiet together. But, it is also calories, and there’s no getting around that. Toddlers who snack on breast milk throughout the day might not come to the table hungry and be ready to eat a variety of foods with the rest of the family. If that seems like it might be an issue for your child, consider fitting breastfeeding into times of day when it is unlikely to interfere with eating, such as before nap and bedtime.

If you’re breastfeeding beyond a year, what do you do to balance breast milk and foods in your toddler’s diet?

Rocking and Swinging Babies to Sleep, In Thailand and the Rest of the World

Posted on April 11, 2013 by ScienceofMom

I’m working on the “sleep strategies” chapter of my book. This chapter is about the strategies that we use to help our babies sleep and how these practices correlate to the development of baby’s sleep patterns.

I’m fascinated by cultural variation in nighttime parenting strategies. However, according to some accounts, there’s a simplistic dichotomy in the way parents around the world help their babies sleep. In most of the world, mothers sleep with their babies and breastfeed on demand throughout the night. Sleep is not a problem, because babies simply aren’t expected to sleep through the night. We in the West, however, don’t understand normal infant sleep. We bend over backwards with all sorts of tricks and gadgets to help our newborns sleep, often alone. (I’m looking at you, swings, bouncy seats, strollers, drives in the car, exercise balls, washing machines.) Then, a few months later, we tire of the antics, grow intolerant of night wakings, and turn to sleep training as the answer.

There is definitely some truth to this. It’s something that I’m writing about in greater detail in my book. But we also know that nothing is as simple as it seems, and infant sleep is no exception. I think it’s helpful to know that parents everywhere struggle with their babies’ sleep or lack thereof, and that’s true regardless of sleep customs or cultural expectations (Sadeh et al. 2011). No matter where they’re born, babies have to acclimate to a world that grows dark and quiet at night and bright and busy during the day. We might use different strategies to help our babies sleep, but there are many similarities as well.

I ran across one of these similarities in a paper I read yesterday (Anuntaseree et al. 2008). Thai researchers surveyed parents of three-month-olds born across the country in 2000. They asked the parents how their babies fell asleep, where they slept, how they were fed, and how often they woke during the night. The parents of more than 3700 babies responded to the survey.

Most of these babies – 68% – shared a bed with their parents. The rest slept in a separate bed but in the same room. Putting babies to sleep in a separate room was nearly unheard of. Of 3700 babies, only two slept alone (a whopping 0.05%). About half were exclusively breastfed, and another quarter were fed a combination of breast milk and formula. On average, these three-month-old babies woke their parents 2.7 times per night, but there was of course a lot of variation here. Nearly 50% woke just one or two times per night. The researchers wondered which factors were related to waking more often, and they found significant correlations with these: male gender, more than three naps per day, falling asleep while feeding, exclusive breastfeeding, and the use of a swinging or rocking cradle.

The gender and napping associations are a little odd and not supported by other studies. However, the rest of it isn’t surprising. It is well accepted that breastfed infants wake more often during the night. Human breast milk is more rapidly digestible than formula (Cavell 1981), so breastfed babies need to feed more frequently. It’s also a common finding that feeding to sleep increases waking (or more accurately, waking the mother) during the night.

But I was really interested in learning more about the swinging or rocking cradles mentioned in this paper. It turned out that 88% of babies commonly started their night in such a cradle. Here’s how the paper described it:

“Use of a swinging or rocking cradle for infant sleep is traditionally used in many Asian countries including Thailand. The typical “getting the infant to sleep” situation in Thailand is for parents to use a cradle as a sleeping aid, and then when the infant falls [to] sleep, transfer the infant to the bed. There has been no previous study regarding the effect of this custom on night waking; our study is the first to demonstrate this association.”

Photos by Jop Timmers

I was curious about what a Thai swinging cradle might look like, so of course, I Googled it. The only photos I found showed a pretty extraordinary contraption:

I found these photos on this design blog and emailed the author, Jop Timmers, to see if I could repost his photos here. He happily agreed, and he told me a bit more about the photos:

“The picture was taken in Kong Chiam, close to the Mekong River and near the border with Laos. The grandmother was trying to make the crying baby of 9 months old to become quiet and go to sleep. The speed was dazzling, but it worked, the boy fell asleep almost instantly. It was a habit of her to do so.”

Anuntaseree et al. consistently refer to “swinging or rocking cradles,” so I assume that the swinging design is not unusual. I’m picturing the rocking cradles as being more similar to the traditional European design, but that’s just a guess. Anyone have more knowledge of these cradles?

There are a few things to point out about this Thai study. For one thing, rocking or feeding to sleep didn’t doom parents to sleepless nights. Plenty of babies in this study fell asleep this way and only woke once or twice. And second, this Thai study just identified associations. (As I said, it isn’t particularly groundbreaking work, but I think it is interesting from a cross-cultural perspective.) As with any cross-sectional study, we don’t know for sure if it is the infant influencing the parenting practices or vise versa. It is surely a bit of both. But several lines of evidence support the idea that parental practices shape baby’s sleep. One study found that mothers’ ideas about infant sleep during pregnancy predicted how many times their babies would wake during the night at 6 months, and this effect was mediated by the way they soothed their babies (Tikotsky and Sadeh 2009). And when parents are counseled, even prenatally, on early strategies to encourage their babies to learn to go to sleep on their own, their babies end up with fewer night wakings (Pinilla and Birch 1993, Kerr et al. 1996, Wolfson et al. 1992). In other words, how you parent around bedtime and during the night has at least some impact on how your baby sleeps.

The strategy of using motion to help babies fall asleep must be universal. We parents find that if we can mimic the motion of the uterine environment in some way, it is often soothing to our newborns. In the first weeks and months of parenting, we’ll do anything to help calm our babies. And really, who can blame us? But, at some point, we often find ourselves stuck with unsustainable sleep associations. Perhaps Thai parents are no different. The baby in the photos above has learned to fall asleep with motion akin to a carnival ride. This kind of environment is actually quite different from the one he experienced during fetal life, and at some point, he’s going to have to learn to fall asleep while his body is still.

I have a love-hate relationship with motion as a sleep aid. We bounced Cee to sleep on an exercise ball for most the first three months of her life, and this may have saved my sanity and feelings of self-efficacy as a new parent. But then I was horrified when I realized that she couldn’t wind down without a fairly vigorous 30 minutes or more of bopping up and down. For her, learning to fall asleep without motion made all the difference in the quantity and quality of her sleep. I wish that I had supported Cee in learning to fall asleep in stillness or even a more gentle, sustainable motion, a bit sooner. Of course, that’s always easier to say in hindsight. At the time, we were surviving one day at a time.

I don’t think we should be afraid to rock our babies to sleep for as long as we want. We should just know that it might be causing baby to wake more later in the night. If that doesn’t appeal to you, consider helping your baby to learn some other ways to fall asleep. If a baby falls asleep in conditions that are similar to those he’ll feel when he wakes briefly during the night, he’s more likely to be able to yawn and go back to sleep. The key is to find opportunities to make that a gentle transition earlier in life, lest you end up with a nine-month-old who requires “dazzling speed” to get some rest.

Did you use motion to help your baby sleep? How did you transition away from that strategy?

While we’re talking baby cradles from around the world, here’s a few more cool cradles that turned up in my Internet meandering. And if you can’t tell, I’m really having a lot of fun with this research!

This one is labeled as a “Primitive African handcrafted baby cradle” and is for sale on 1stdibs.com.

primitive african

A gorgeous Japanese cradle, dated 1701-1850, inlaid with tortoise and abalone shells. I wonder if that hole in the bottom third has something to do with diapering or lack thereof?

Photo from Science Museum, London

An Italian cradle, dated 1600-1750, made of fabric covered in plaster.

Photo from Science Museum, London

And finally, here’s a modern cradle with a cool design. Of course, you might prefer to just hold your baby if you’re going to rock him to sleep, but this cradle does eliminate the delicate transfer maneuver (although this doesn’t look like a safe place for a baby to sleep unsupervised for the night).

Guest Post: What the World Looks and Sounds Like to a Newborn Baby

Posted on April 8, 2013 by ScienceofMom

Hi-ResBrinkCover I am delighted to have a guest post from Author Susan Brink today. Susan’s book, The Fourth Trimester: Understanding, Nurturing, and Protecting an Infant Through the First Three Months, was released a few weeks ago. I really enjoyed this book. It is billed as an “operating manual” for newborns, but it read to me more like an “understanding manual.” This is actually more helpful, because if you can understand why your newborn is doing the things she’s doing, you’re on your way to figuring out how you and your baby will survive and thrive in this period. The Fourth Trimester includes chapters on crying, sleeping, feeding, sound, sight, touch, physical development, and stimulation. Each is full of both science (well-cited, I might add) and stories from real parents. The sight and sound chapters were two of my favorites, so I’m happy that Susan chose these topics for her guest post on Science of Mom. Enjoy!

WHAT THE WORLD LOOKS AND SOUNDS LIKE TO A NEWBORN BABY

By Susan Brink

Imagine yourself in Paris, and you don’t speak French. Pretend for a moment that you’re from rural America, have never seen a big city much less the elegant capitol of France, and you’re trying to cross the Champs-Elysees at the Arc de Triomphe. You dare not step into traffic, you can’t read the street signs, and you cannot understand what people are trying to tell you. Sights and sounds overwhelm you. Nothing makes sense.

That’s something to think about when wondering what the world looks and sounds like to a newborn baby. But there’s more. Dr. Alison Gopnik, professor of psychology at the University of California, Berekley, adds two elements to the confusing mix: love and caffeine. “You want to know what it’s like to be a baby?” says Gopnik. “It’s like being in love for the first time in Paris after four double espressos. It’s fantastic. It’s a wonderful state to be in. And very likely, you’ll wake up at three a.m….crying.”

We look into a newborn baby’s eyes and wonder what he sees. We watch her reactions and wonder what she hears. But now we’ve got a wealth of recent research into what newborns see and hear that adds scientific chops to what parents have been imagining for ages.

Vision

After counting fingers and toes, the first thing most parents do is gaze into their infants’ eyes. We tell ourselves that they’re looking right back. But what, exactly, do they see?

We know that vision is the least developed sense at birth. Babies have heard their mothers’ voices through layers of flesh and organ for nine months already, and they recognize her voice at birth. But they have no similar recognition of her face. Already, they can discern contrast and are drawn to the shadows of eye sockets and the edges of faces. But vision has multiple components, including focus, contrast, coordination between eyes, depth, distance, and color. Their developing brains must lay down dendrites and create synapses between cells in visual areas of the brain, the networks that send and receive signals.

Even as that important brainwork is going on, parts of the eye itself must physically develop. At birth, an infant can project a clear image onto the retina, the light-sensitive tissue at the back of the eye. The images are converted to electric signals and sent on to the brain to interpret. But the fovea, the part of the retina that gives good, detailed vision, is not yet mature. The muscles controlling coordination of binocular vision aren’t yet strong. And the brain architecture that will eventually interpret the signals is not yet up and running. So when a newborn baby looks at an object, the clear image received by the retina falls on a fovea too immature to transmit a clear image to visual areas of the brain. And those visual areas are themselves just beginning to form. In time, the fovea will mature and pass on clear images. And with every visual sensation, the brain adds structure to enable more complete vision.

With every open-eyed observation that passes their way, information is making its way from the eye to the developing visual centers of the brain.

In other words, vision develops through the inevitable practice of looking around.

What Infants See Right Away

Almost from birth, infants are drawn to contrast. We tell ourselves that the baby is looking right into our eyes. If she is, it’s because she notices the contrasting shadow of the eye socket. But it’s equally likely she’s looking at the edge of our face because she’s drawn to the contrast of head against background. For example, newborns can see measurable contrast between very light and very dark objects. At a distance of one foot, they can see high contrast black lines on a white board—lines only 1/16” wide. They notice movement of large, high-contrast objects. In another month, they’ll see some reds and greens. By two months, they’ll be drawn to all the details a loving face, not just the edges and shadows; and they’ll begin to respond to more subtle motions, like the movement of a hand in front of their faces.

There is important visual work going on in the months before a baby actually sees. If the visual pathways, ripe for development early in life, are completely blocked during crucial early periods, the result will be permanent visual impairment. But relax. A healthy baby living within anything resembling a normal human environment will not have those critical pathways blocked.

Research using animal models in the 1960s showed why early visual experience is so important. In experiments done with newborn kittens, scientists sewed shut one eye of each kitten and left it that way for several weeks. When the sutures were removed and the eye allowed to open, the kitten still could not see from that eye, even though the eye was perfectly healthy. What the experiment showed was that if the eye and brain fail to make connections during crucial periods of development, the visual cortex undergoes dramatic reorganization and vision never develops normally.

David Hubel and Torsten Wiesel, Nobel Prize–winning scientists who pioneered this vision work, repeated their work with monkeys. They found that in the normal monkey brain, there are columns of neurons in the visual cortex. Each column receives input from one eye, and the columns alternate between those dominated by information sent from the left eye and those dominated by information from the right eye. The alternating columns allow the brain to start putting that information together as binocular vision.

But among the monkeys deprived of vision in one eye, the neural columns dominated by the seeing eye became wider. The neural columns associated with the blinded eye became narrower. It became clear that in order for monkeys or kittens to see normally, they had to have visual experiences during the earliest weeks of their lives. Without it, the brain’s capacity to make the necessary neural connections was gone.

But the world provides exactly the right visual stimulation for healthy infants without the need of special toys or mobiles. We all have blue sky above, and green trees below and the view of the firmament through branches is a glorious feast of vision. And quite simply, there is nothing an infant likes better than a close-up view of a parent’s face.

It’s a difficult and imprecise business, knowing what a baby is seeing or recognizing. But parents and babies have always gazed into one another’s eyes. It’s deeply rooted, it’s bonding, it’s complex—and it’s important.

Sound

A fire truck screaming, a vacuum cleaner roaring, a talk show host droning, grown-ups chattering, children nattering, dishes clattering. For a newborn baby, the sounds are all there, but the brain isn’t ready to assign more or less importance to any one of them. As a fetus, he heard most of it before, but in utero the sounds were mercifully muffled, almost soothing. The most soothing of all sounds in the new world no doubt is also the most familiar—mother’s voice. Newborns recognize their mothers’ voices, turning toward them more readily than toward any other voices.

Hearing is the most highly developed sense at birth—but newborns cannot yet discern what is worth listening to and what can be safely ignored. They don’t yet have the skill to know where a dog bark ends and a screaming sibling begins, much less to know where one word ends and another begins.

But during the first three months of life, they set about the work, bit by bit, of organizing the sounds around them.

Sorting Through the Din

Think of newborn hearing as a passive exposure with the baby’s brain soaking up sounds and being bathed in the acoustics of his surroundings. Just as each little peek of vision is sculpting new brain circuitry to enable sight, each phrase and sentence sets up the brain wiring that will soon allow the baby to understand where one word ends and another begins. Long before she utters her first “ma-ma” or “da-da,” she’s building the foundation for speech and understanding language.

Babies begin to learn language by listening. And they need to hear human voices. Television and video doesn’t work. That’s because part of what’s needed to learn is human interaction. They learn early on that even their accidental sounds—a burp, a sneeze, a hiccup—get a reaction: a back pat, a gesundheit, a startled look. Soon, another kind of accident happens. The baby leans his head back, the tongue hits the roof of the mouth, and a “g” or “k” sound emerges as he exhales an “oo” sound. It’s a coo! And research tells us that when parents coo back, infants respond by babbling more.

All babies around the world are born with the ability to recognize every sound made in every language on earth. But within months, we lose that ability. The brain is an efficient organ, and just as it’s busy building the connections it will need, it also works at pruning away those neurons that will not be needed.

Dr. Patricia Kuhl, a neuroscientist and professor of speech and hearing at the University of Washington and a leading expert on speech development, discovered why it is that Japanese people have difficulty mastering the ra and la syllables of the English language. Dr. Kuhl and her colleagues tested infants using special pacifiers connected to computers. The infants loved new sounds, and sucked up to eighty times a minute to keep the sound going. But infants, like all of us, get bored with repetition. They eventually slowed down after hearing the same sound over and over. Then as a new sound was introduced, they again sped up their sucking.

Using these special pacifiers, researchers found that infants as young as one month of age heard all sound distinctions— the ones that would become part of their native language, as well as others that they were unlikely to hear as adults. The Japanese babies in the study could tell there was a change in sound when they heard rake and then lake. Japanese adults cannot make the distinction—even the Japanese scientists involved in the experiment couldn’t do it.

When tested at ten months of age, the Japanese babies could no longer make the distinction. If they heard the ra sound long enough to get bored, and then the sound changed to la, they remained bored and inattentive. Whatever inborn ability they had to make the distinction was lost to brains that were preparing themselves for the sounds that would be needed in Japan.

And so it is around the world. A French baby and an American baby have the same ability, for several months, to hear the guttural, rolling r of the French language. Within ten months, the American baby has lost it, and if she tries to learn the French language as a teen or an adult, the unnatural attempt to say rouge or après can be challenging, if not downright embarrassing.

Babies love the sound of voices, the lilt of language. They want it to be interactive. They want to connect facial expressions to words, and every word you utter—for this brief period of time—will be completely fascinating to this listener.

It seems that, once again, nature and biology know what they’re doing in giving sound a head start on vision The world is a confusing enough place to enter with good hearing. It’s probably best that infants are more able to begin understanding sounds as their brains quietly go about the business of developing vision.

Susan Brink is a freelance medical writer. Her book, “The Fourth Trimester: Understanding, Nurturing, and Protecting an Infant Through the First Three Months,” is published by the University of California Press and was released March 20, 2013.

Welcome to the Carnival of Evidence-Based Parenting! First Edition: Preschool

Posted on April 2, 2013 by ScienceofMom

Welcome to our first edition of the Carnival of Evidence-Based Parenting!

What is a blog carnival? It’s a collection of blog posts, all focused on one theme, submitted by various bloggers. We plan to hold our carnival every month or two, rotating hosts to different blogs and choosing a new theme for each carnival. Bora Zivkovic of A Blog Around The Clock wrote about blog carnivals in his post on the history of science blogs. Carnivals aren’t as common now as they once were. Instead, bloggers are sharing their work through social media outlets. But as Bora wrote, carnivals do something that social media can’t: “Each edition of a carnival is a magazine, a snapshot of the moment, and a repository of pieces that both their authors (by submitting) and hosts (by accepting) thought were good and important.” This is what we’re hoping to capture in our collections of posts on parenting and science.

Since I have the honor of being the first host of this Carnival, I’ve been thinking about what “Evidence-Based Parenting” means to me.

If you had asked me what evidence-based parenting meant when I first became a mom, I probably would have said something along the lines of, “doing everything right.” Now I know better.

I know that parenting is complex. I know that there are countless factors that enter into our parenting decisions, and even the best science can’t describe all of those variables. I’m a scientist by training, and I like to see data when I’m faced with a tough decision. But if I’m wondering if preschool is right for my kid, then I know that looking at the data will give me some ideas about important considerations and average outcomes, but it still isn’t going to tell what is the right choice for my child.

Why, then, do we care about the science? There’s something about parenting that invites judgment and controversy. Maybe it’s because we care so much about getting it right, but deep down, we’re afraid we’re doing everything wrong. Pick a parenting controversy, do an online search, and you’ll find strong voices supporting opposing sides. They’ll also both be citing science to back their opinions. My only solution to cutting through the spin in these cases is to get to know the field and broadly understand the evidence base for it. Or perhaps better still, since we’re busy parents and all, find someone you trust who can do this for you. That’s what this carnival is all about: science-minded bloggers compiling some of our best resources on a given topic to bring you a summary of the important science. It’s helpful (and more fun!) to work together on this, because we know that a true base of evidence requires multiple viewpoints, all committed to looking through the lens of science.

Evidence-based parenting means recognizing what we don’t know as well as what we do. It is an attempt to understand the questions as well as the answers. It isn’t a search for the One Right Way so much as it is a quest to understand the variation, complexity, and bias inherent to real life. After all, no scientist will tell you that their research has answered all the questions; instead, they know that every new experiment uncovers both new knowledge and new questions. To me, it is this spirit of curiosity that defines evidence-based parenting.

Let’s get to the posts for our first Carnival. Preschool: Do you need it? What kind is best? How can we even measure that?

Melinda Wenner Moyer’s piece on Slate, The Early Education Racket, stimulated a lot of conversation in my parenting circle. “Research suggests that if you have the time and money to argue over the merits of a Waldorf preschool versus a Montessori one, little Emma isn’t going to suffer either way. In fact, she probably doesn’t need to go to preschool at all,” Moyer writes. Start your Carnival reading here and breathe a sigh of relief. Your kid will probably be OK, whatever choices you make for preschool.

I know you’re still curious, though, so keep reading.

Over at Momma Data, Polly Palumbo lays out the evidence for why play is so important for preschoolers. Children learn naturally through play, and research shows that direct instruction like that found in academically focused preschools might actually get in the way of children’s curiosity, creativity, and natural development of problem-solving skills.

Jessica Smock of School of Smock writes about families that are opting out of formal preschool altogether and instead choosing to home school their preschoolers. Jessica explores some of the reasons behind this choice and what exactly a home-based preschool “curriculum” looks like. There are companies out there that will happily sell you a curriculum package with promises of giving your kid a jump-start in math and reading, but Jessica cautions against this approach. What preschoolers really need is – you guessed it – play! That’s true whether your child is learning at home or in a classroom.

Here on Science of Mom, I tackled another question that might play into your choice of preschool: Which is a better preschool environment, mixed-age or single-age classrooms? I wanted to learn more about this question because Cee is currently in a mixed-age, at-home daycare (not technically a preschool, but close enough for me). I found lots of interesting studies on the effects of age composition on children’s learning, but I also had fun critiquing those studies.

In her post, Momma, PhD gives her own account of the factors that went into choosing a preschool for her daughter. As a working scientist herself, Momma, PhD knows that kids are natural scientists, and the way they experiment is through play. That was a major factor in their preschool decision. She and her husband ended up choosing a modified Montessori program, so you’ll definitely want to read this post if you’re interested in this teaching philosophy.

Speaking of scientists, Jeanne Garbarino, Biology Editor at Double X Science, submitted a piece she wrote for Agora. Jeanne writes about her daughter’s natural curiosity about science and ponders how to answer her questions. She comes back to recent research about how kids learn best. It isn’t through direct instruction, even when your mom knows the answers. It’s about letting kids discover answers on their own and acknowledging that the process is just as important.

Jennifer Doverspike of Six Forty Nine sorted through a tremendous amount of research in search of answers to an important question: How do we define quality in preschool? And in a word, it’s complicated. And difficult. (OK, two words.) That’s actually not a big deal to many of us, because chances are good that we’re choosing between several high quality preschools. But it matters a lot to families who don’t have much choice, like those sending their kids to local Head Start programs. How do we give those kids the best preschool experience possible, and do it on a mass scale? These questions are really important to education policy. (This post is actually Jennifer’s third in her series on preschool. She’s also written recently about if preschool is necessary and if Head Start works.)

Suzanne Barston of Fearless Formula Feeder wondered if she should be concerned about the teaching style at her kids’ “down-home” preschool, but she quickly learned that the research is confusing and hard to interpret if you’re looking for answers to your personal preschool questions. “But through the panic, the uber-rational devil on my shoulder kept whispering “does it really matter? It’s preschool.” Sometimes recognizing the limitations of the science provides just enough reassurance to trust your gut, and that’s a good thing.

Finally, Tara Haelle at Red Wine and Apple Sauce walks us through a recently published study on the success of one preschool program. It’s helpful to look closely at one study in this way, because then you can start to see the limitations inherent to any single study. That’s something that you might not learn from media accounts of hot new research. Real outcomes from preschool are hard to study, so it takes a lot of work to understand what is effective and what isn’t. Like all of science, it isn’t a single study but rather a body of evidence that matters.

I loved reading all of these posts, and I encourage you to click through and check them out. Even though we tackled different questions, there was a clear theme that emerged. We all recognized the importance of play and discovery in preschool, and we were cautious about pushing kids to an academic curriculum too soon. That’s interesting coming from a group of highly educated women. I can’t help thinking, if Cee is going to follow in the footsteps of her parents, she may have a few decades of school ahead of her. Why not play a little longer?

We’d love to hear your comments – here or on our individual posts. How did you choose preschool – or not – for your children? How much was science and how much was gut?

You can also follow our discussion on Twitter with the hashtag #parentscience.

A quick list of our contributors for this First Edition of the Carnival of Evidence-Based Parenting:

The Early Education Racket (Melinda Wenner Moyer)

Preschool Should Be Less School and More Play? (Momma Data)

Preschool at Home? Let the Children Play! (School of Smock)

Mixed-Age Preschool: Benefits and Challenges (Science of Mom)

Picking a Preschool (Momma, PhD)

On parenting (and teaching) in the name of science (Jeanne Garbarino)

Universal Prekindergarten: Evidence from the Field (Six Forty Nine)

Preschool Schmeeschool (Fearless Formula Feeder)

What Can We Learn from a Single Preschool Study? (Red Wine and Apple Sauce)

Mixed-Age Preschool: Benefits and Challenges

Posted on April 2, 2013 by ScienceofMom

My daughter, Cee, is almost two-and-a-half. Five mornings per week, she is cared for by an in-home childcare provider I’ll call Amanda. On a given day, Amanda and an assistant care for between four and eight kids ranging in age from one to six years old. The one-year-olds are just starting to walk. The six-year-old, who also attends half-day kindergarten, can read and write.

One of the reasons why we chose Amanda’s for childcare is that it allows Cee to interact with kids of different ages. When I first visited Amanda’s, the problem-solving and conflict resolution that I observed among the older kids impressed me. It was refreshing to watch, particularly after visiting chaotic childcare centers with rooms of as many as 10 two-year-olds. I imagined that Cee would learn so much from observing and playing with these more mature children.

When Cee began daycare last fall, we watched as two older girls took her under their wing, reading her stories and including her in their pretend play. Suddenly Cee was acting out complex stories at home, too, as she became aware that her imagination could make all kinds of fun. She was making us coffee, asking if we wanted it hot or cold, with milk or sugar. She was hushing us because her baby doll was sleeping. And she could not stop talking about her friend, the kindergartener, who rode on a real, honest-to-goodness school bus. We also watched, proudly, when she stuck up for herself and brushed off older kids if their play was too intense for her. She seemed to make a huge developmental leap within a couple of weeks of starting childcare.

Delivering Valentines to her friends

I’ve also noticed that the friend that Cee talks about the most at home, and the one that she hugs the longest when she says goodbye, is a little girl just 2 weeks younger than her. I’ve witnessed them engaged in complex, interactive play together, where neither is the obvious leader or follower. And while I think Cee is doing great in her mixed-age childcare setting, I wonder if I’ll feel differently about this as she gets older. We could keep her at Amanda’s through kindergarten, but when she’s four or five, will hanging out with toddlers be a bore? Should we consider moving Cee to a preschool where she’ll be surrounded by kids her own age? Is mixed-age grouping helpful for preschoolers, or does it slow them down?

Child development experts have debated the merits of mixed- vs. single-age classrooms since the 1930s. Soviet psychologist Lev Vygotsky was an early proponent of mixed-age learning. He thought that the best way for children to learn was through interaction with older, more competent children who could set good examples for cognition and behavior. According to Vygotsky, hanging out with older children pushes younger ones to learn more than they would be capable of learning on their own. In contrast, Jean Piaget, well-known for his theory of cognitive development, believed that children learn best from peers close in age, well-matched in knowledge, skills, and power. With their peers, children can learn to solve problems organically and to practice playing a variety of roles in solving them, rather than always being guided in how to fix things by an older, more experienced child.

Decades of research haven’t been able to clarify whether mixed-age or single-age classrooms make for better preschool environments. Some studies point to benefits of mixed-age grouping, similar to my own observations. Toddlers who have a chance to play with slightly older kids seem to develop more complex language and types of play (Rothstein-Fisch and Howes 1988; Howes and Farver 1987). And in mixed-age classes, older children have opportunities to practice leadership skills and prosocial behaviors, like helping and sharing (Derscheid 1997; French et al. 1986).

Mixed-age classrooms might also have the benefit of muddying age-based comparisons and competition between children – a good thing, I think – because there is likely to be a naturally wide range of skills and abilities within the class. As a parent, it is hard to fret that your child is behind the curve if there is no real curve. And teachers might be more likely to work with children where they are, focusing on their individual interests and skills rather than expecting the entire class to move linearly through milestones and achievements. Plus, mixed-age classes make it logistically easier to keep the same teacher with a group of kids for several years, maybe decreasing the stress of abrupt classroom and teacher changes for young kids (Whaley and Kaplan 1992).

However, there is also a fair amount of research pointing to problems with mixed-ages, the main concern being that mixed-age classrooms don’t challenge older children enough. For example, one study found that older children in a mixed-age setting were more likely to be hanging out solo, detaching themselves from the rest of the group, than if they were in a class of closer peers (Urberg and Kaplan 1986). Another found that older children were less likely to take part in teacher-led activities in mixed-age groups, probably because it is challenging for teachers to plan activities that are appropriate for a broad range in ages (Goldman 1981).

We’re starting to see a pattern emerging here, right? Mixed-age classrooms seem to generally work well for the younger kids in the group, but the older kids might be missing out. A 2002 study headed by Adam Winsler of George Mason University illustrated exactly this pattern in a university-affiliated child development center with morning-only care and a child-centered, play-based philosophy. This study was unique in that it took advantage of the center’s switch from single-age to combined 3- and 4-year-old classrooms, tracking children’s behavioral and cognitive development during the years before and after the switch. Research assistants carefully observed the minute-to-minute activities of the children. Were they engaged in a focused, goal-directed activity? How long was their attention focused on that activity? Were they working alone, with another child (close or distant in age), or with a teacher? A limitation of this design (and most studies like it) is that it can’t be blinded, so it’s possible that the researchers were just seeing what they wanted to see. However, that specific checklist of observations decreases the chances of this being a problem.

How did the children’s behavior differ between single-age and mixed-age classrooms in Winsler’s study? When kids were in single-age classrooms, the 4-year-olds were more “on-task” and had longer attention spans for a given activity. They also spent more time with their peers and less time with their teachers compared to the 3-year-olds. But when those two age groups were combined into one room, the age differences essentially disappeared. The 3-year-olds started acting more like 4-year-olds, and the 4-year-olds started acting more like 3-year-olds. For example, in single-age classes, the 3- and 4-year-olds were working on goal-directed activities 63% and 85% of the time, respectively. When they were thrown into a room together, those numbers shifted to 71% for the 3-year-olds and 70% for the 4-year-olds.

Reading this study got me thinking about the challenges of figuring out what exactly to measure if we’re trying to quantify effectiveness of a preschool program. This isn’t my field at all, so these study methods were new to me. (And, to be fair, the Winsler study is more than a decade old, and the research methods of the field have no doubt changed since then.)

For example, what exactly does it mean for a 3-year-old to be “goal-directed”? Here’s how the Winsler paper described it:

“Goal-directed activity was defined as behavior by the child, which appeared focused, organized, and had an identifiable goal or end point to the activity… Examples of goal-directed activity… included building a structure out of Legos or some other assembly/construction materials, doing a puzzle, playing a game with rules, or engaging in an organized make-believe episode of ‘house.’ Nonexplicitly goal-directed behavior in this context included, for example, aimless wandering around the classroom, looking on into another group’s activity, repeatedly spinning a puzzle piece around one’s finger for the apparent ‘fun of it,’ and making a transition between one activity and another.”

I get that we like to see kids focused on a project or game. Learning is more obvious in this context. But I wouldn’t disregard daydreaming as unproductive activity; science is revealing that daydreaming is actually an indicator of a busy and active brain. And who’s to say that a child isn’t learning a great deal from observing other kids? Or that repeatedly spinning a puzzle piece around one’s finger isn’t the beginning of a passion for physics? Maybe being an older kid in a mixed-age group means spending less time on “school-readiness” activities and more time playing alone and developing empathy and leadership, but how much does each of these contribute to how your kid will ultimately get along in the world? How much do we really know about how kids should and shouldn’t be spending their time?

To their credit, Winsler et al. make this exact point:

“The finding that 3-year-old children in MA [mixed-age] groupings are stretched a bit behaviorally while this is not the case for the 4-year-olds would appear to give some support to the fears reported by parents who typically prefer their child to be the younger child in MA settings (Lloyd, 1999). However, it is important to point out that these data (nor the data from any other studies for that matter) do not imply that MA classrooms are bad for the older children in such classrooms. First of all, it is not clear that the outcome variables in the present study on which the age-by-age-composition interaction effects were observed (sustained activity, goal-directed activity, time spent with peers and a teacher) are predictive of child competence and later positive outcomes. Secondly, there could easily be other advantages to MA grouping for the older children (like the diversity of social experience afforded by increased gender and age desegregation or other social climate variables not explored in the present study) that balance or outweigh these findings.”

In other words, it is difficult for science to capture all the factors that might impact your child’s experience in preschool. Of the factors that we can capture, we’re not even sure how important they really are. Labeling one type of classroom as “better” and another as “worse” is bound to be a gross oversimplification. What the research does show is that the age composition of a classroom impacts how children spend their time, for better or for worse.

This research, with all its limitations, can be useful for informing education policy. For example, more 3-year-olds are now entering Head Start programs. Should Head Start classrooms mix 3- and 4-year-olds together, or should they keep them separate? If they’re mixed, then the research in this field can help highlight important aspects of teacher training, such as strategies for ensuring that children of all ages and abilities are engaged and challenged in their work. A couple of recent studies have looked specifically at the Head Start question, and again, found mixed results (Moller et al. 2008; Bell et al. 2013). There’s a lot more to learn about age composition in preschool classrooms.

Clearly “goal-directed”: Collecting eggs at Amanda’s

I don’t know whether we’ll move Cee to a more traditional preschool before kindergarten. But I like knowing about this research, because it will keep me thinking as I watch her grow up among her dear friends. I’ll be watching to see if she seems bored or disengaged from the group. But there are other factors that will play into our decision, like the stress of moving to a new school and her attachment to Amanda. For Cee, my priorities are that she be in a place where she is happy and feels safe, has lots of opportunities to play solo or with other kids, and that she grows her confidence in social situations. And to be honest, I’m glad she’s in a place where daydreaming isn’t discouraged.

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