Category Archives: Newborns

Mode of delivery and childhood illness: A randomized trial in 2004.

03c62f38ce31d41b01e1b5a4031bf11aOne of the biggest difficulties in proving a causal link between cesarean birth and chronic health problems in childhood is the type of research studies that can practically and ethically be done during pregnancy.

The gold standard in medical research is the randomized controlled trial (RCT). In an RCT researchers randomly place subjects into either “treatment” or “control” groups, then expose the treatment group to something—a new vaccine for Infection X, for example—and then compare outcomes in the two groups later on. (In this example, how many kids in the treatment [vaccinated] group came down with Infection X versus how many in the unvaccinated control group?) If there’s a significant difference in outcomes between the two groups, you’ve got a strong argument that the treatment made the difference.

How a randomized controlled trial works. (Credit: SUNY Downstate Medical Center)

How a randomized controlled trial works.**

As you can imagine, randomly assigning pregnant women to cesarean (treatment) or vaginal birth (control) groups is nigh onto impossible—ergo, you can’t do an RCT. This means that virtually all research studies on the issue of cesareans and chronic childhood have been observational in nature—looking backward in time at databases, for example, or trying to fish significant trends out of hospital registries, birth cohorts and the like. The best an observational study can tell you is that A and B are associated with one another, but that’s it—you can’t prove that A actually causes B. An observational study can’t prove that cesareans are a cause of asthma; it can only say that cesareans are associated with an increased risk of childhood asthma.*

So mode-of-delivery RCTs are out of the question…or are they? Actually, in 2004, a Canadian research team did one.

Well done, Northern Neighbors!

Well done, Northern Neighbors!

The multi-center, multi-nation Term Breech Trial wasn’t about whether cesareans might increase the risk of childhood asthma, diabetes and such. It was about trying to figure out whether elective cesarean section or vaginal birth was the safest way to deliver a breech baby at term. Since the existing research was somewhat murky at the time, it was considered ethical (with informed consent) to randomize women to have either a planned cesarean or attempt a vaginal birth.

The particulars of the breech birth debate are best left for another post, but tucked away in the study’s results section was this little nugget:

“…more parents in the planned cesarean birth group than the planned vaginal birth group reported that their children had had medical problems in the past several months…relative risk, 1.41; 95% CI, 1.05-1.89; P=0.2.”

Plain English version (mine): The toddlers who had been in the planned cesarean group were about 40% more likely to have been sick in the previous few months than those in the planned vaginal birth group. The types of medical problems—typical 2 year-old stuff like colds, ear infections and stomach flu—were no different between the groups. The only difference was in the numbers of children who’d gotten sick.

As is the case with all medical research, you can find things in the study to complain about: relatively small numbers, for example, the use of parental questionnaires and the fact that some mothers in planned vaginal birth group ended up having cesareans (and vice-versa), etc.

But here’s my bottom line:

In a randomized trial of pretty well-matched subjects, those babies whose mothers were in the planned cesarean group tended to get sick more often than those in the planned vaginal birth group.

This doesn’t address the issue of chronic illnesses like asthma, type 1 diabetes and the like, but it does support the theory that cesarean birth can mess with a baby’s developing immune system.

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*Here’s an exaggerated example of the trouble with mistaking association for causation: Virtually all adults who die suddenly of heart attacks drank water in the 24 hours before they died. So, drinking water is associated (time-wise) with heart attacks. But you would be wayyyy wrong to say that, based on that association, a glass of water can cause a heart attack.

**Credit: SUNY Downstate Medical Center

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Filed under Asthma, Canada, Cesareans, Immune system, Maternal-child health, Newborns, Vaginal birth

Pollution and birth weight

Beijing in January

Beijing in January

What with continuing air pollution woes in such diverse locales as Beijing and Salt Lake City,  a study released last week in Environmental Health Perspectives–which found a direct relationship between particulate air pollution and low birth weight in term babies–couldn’t be more timely.

The study’s authors compiled data on more than 3 million births in nine countries and found a 10-15% increased risk of low birth weight in the most polluted locations.

This isn’t just about turning out slightly less pudgy newborns. The consequences of low birth weight are far-reaching, even multi-generational. Low birth weight babies are more likely to develop chronic health conditions as they grow up, like heart disease, hypertension, and diabetes–just the sort of health problems that make for high-risk pregnancies a generation down the road.

In other words, today’s low birth weight baby girl is more likely to one day produce an unhealthy baby of her own. It’s a cycle that’s tough to break once it starts, and this study is more food for thought as world leaders (hopefully) get serious about addressing climate issues.

(Photo credit: jaaron)

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Filed under Environment/Toxins, Maternal-child health, Newborns

Surgery-saving prenatal intervention or nefarious anti-lesbian plot? You decide.

First do no harm?

First do no harm?

If you’re in the mood for a science-wonky tale of hormones, gender roles, a possible anti-lesbian plot, and a ‘medical intervention-versus-human experimentation’ controversy,  skip on over to a post I wrote for Our Bodies Ourselves (OBOS) in December.

The subject? Prenatal treatment of congenital adrenal hyperplasia (CAH), a rare inherited defect in hormone production that leads to an overproduction of male hormones in utero. CAH can cause deformity of the developing female genitalia (male genital development is unaffected), and can also lead to more “masculinized” behavior in affected girls and women. Though most are heterosexual, women with CAH are more likely to be lesbian or bisexual than the general population.

The prenatal treatment of CAH, in which mothers take very high doses of a steroid medication their entire pregnancies, is primarily intended to prevent genital deformity in girls. But some critics suspect a hidden agenda–the prevention of masculinized behavior and, by extension, lesbianism.

Other critics point out that very few affected girls really need the very aggressive genital surgery performed in the past, and that very high doses of prenatal steroids appear to increase the risk of serious consequences for treated children, including poor growth, learning disabilities, and even mental retardation. Such alarming reports have led many researchers in the United States and Europe to call for an end to the practice.

Still, Dr. Maria New, a pediatric endocrinologist in New York–by far the most prominent advocate of prenatal treatment–has declared the practice to be effective and “safe for mother and child.” Problem is, she and her colleagues haven’t been very diligent in following the babies they’ve treated over the last three decades, so the real risks of the prenatal steroid therapy aren’t yet completely known.

There’s much more detail in the post, and if you’re not feeling science-y enough to tackle that one, fear not. I’ll be back with lighter fare soon!

PS: Even if you’re not feeling science-y today, head to OBOS and donate money to that very worthy organization! Start racking up those 2013 tax deductions!

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Photo credit: Jason Pratt

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Filed under Development, Newborns, Science, Sex & Sexuality

Back in the saddle…at Science & Sensibility

Some days are like that…

Been away from the blog too long! But I haven’t been snoozing…

Science & Sensibility just put up a post of mine about delayed cord clamping (DCC)–i.e., the practice of waiting 2 or 3 minutes after birth before clamping the umbilical cord.

It’s hard to believe that it’s so difficult to get maternity care providers to sign on to DCC (versus immediate cord clamping, or ICC) in uncomplicated vaginal births. The benefits of DCC–better iron stores for babies, improved cardiovascular transition from fetal life to babyhood, and a big dose of stem cells–are well known, and there’s no evidence that ICC is beneficial to anyone. Still, tradition is a hard habit to break, especially when it comes to medical practice.

So skip on over to S&S and have a read!

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Filed under Cord clamping, Maternal-child health, Natural childbirth, Newborns

How babies learn: It’s all in the porridge

“She’s just using a ‘principled inferential process’, dear.”

How do babies decide what to concentrate on as they learn the ways of the world? And how do they keep from being overwhelmed by a world in which everything is new? Surprisingly (or maybe not), they act a lot like adults.

Writing in the journal PLoS ONE, Celeste Kidd and colleagues at the University of Rochester describe how babies learn: they use a “principled inferential process” and “appear to allocate their attention in order to maintain an intermediate level of complexity.”

Say what?

Fortunately Kidd saves the day by naming the process “the Goldilocks Effect.” (Quick refresher: Goldilocks stumbles into the bears’ cottage, finds their porridge to be either too hot or too cold, whines about her porridge-fate until she finally discovers a warm-ish bowl that’s “just right.” She eats it, settles into a “just right” bed, and goes to sleep. When the bears return they do not eat her, for reasons I’ve never quite understood.)

Kidd found that babies tend to spend most of their visual attention on things that are neither too simple nor too complicated. That is, they are attracted to “just right” complexity–enough to stimulate their brains, but not so dull as to put them to sleep, or so complex as to fry their little noggins.

This study confirms what many parents have long known: babies will seek out the level of stimulation in their environment that is appropriate to their learning needs. Bombarding them with extra, too-complex stimulation doesn’t accomplish much, other than to overwhelm them.

Watch a baby and you’ll know how much stimulation is too much. They simply look away when they’ve had enough. Kind of like me in my college calculus class…

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Filed under Development, Newborns, Science

Jailing addicted new moms: A slippery slope?

Two troubling articles about pregnant women, addiction, and the law came out this week.

1) The first, in the most recent New York Times Magazine, describes how Alabama is increasingly handing out long jail sentences to drug-addicted new mothers. The charge? “Chemical endangerment of a child,” a Class A felony in Alabama that carries a mandatory 10-year sentence.

Emma Ketteringham, the director of legal advocacy at the National Advocates for Pregnant Women (NAPW), is particularly rankled by the use of the “chemical endangerment” statute to prosecute addicted women. The law was originally drawn up to protect children from the dangers of parental meth labs and the like; it was never intended to be used against pregnant women struggling with the disease of addiction. From the Times article:

[Ketteringham] argues that applying Alabama’s chemical-endangerment law to pregnant women “violates constitutional guarantees of liberty, privacy, equality, due process and freedom from cruel and unusual punishment.” In effect, she says, under Alabama’s chemical-endangerment law, pregnant women have become “a special class of people that should be treated differently from every other citizen.” And, she says, the law violates pregnant women’s constitutional rights to equal protection under the law.

It also makes it much less likely that an addicted woman will seek help during her pregnancy, thus putting her child in even greater danger–a point which seems to have been lost on the state’s legislators.

The push to prosecute drug-addicted pregnant women is actually part of the larger effort to pass “fetal personhood” laws (which have been introduced as initiatives and measures in 22 states to date), which declare that a fully constitutional-rights-endowed person is created the moment sperm meets egg.  A major problem with this view, according to Lynn Paltrow, executive director of NAPW, is that:

“… there is no way to treat fertilized eggs, embryos and fetuses as separate constitutional persons without subtracting pregnant women from the community of constitutional persons.”

In other words, from the moment of conception a woman’s rights would be superseded by those of her fertilized egg.

2) Okay, so getting jailed on a PWA (pregnant-while-addicted) charge may seem like a distant concern for most Americans–the vast majority of pregnant women in the U.S. are not drug-addicted, after all.

But hold on a moment. As the second article (from the Washington Post) points out, the number of pregnant women addicted to prescription painkillers has tripled in the last decade, including many women who are being treated for very legitimate pain issues–not the “typical” drug addict so often reviled in the media.

The Alabama law makes no distinction between “medical” addiction to painkillers (prescribed after a car accident, say), and “recreational” addiction to heroin or crack, and in a way, they’ve got a point. From a baby’s standpoint it doesn’t matter why mom’s addicted, so why not prosecute them all? There hasn’t been a legal stampede to throw the book at moms on Vicodin as yet, but it shouldn’t take a politically ambitious Alabama attorney too long to figure that one out.

Spending a decade in jail for the “crime” of having a baby while addicted to a doctor-prescribed treatment may seem like a stretch today, but today’s stretch is often tomorrow’s norm. As Rush Limbaugh-esque politicians steadily chip away at women’s reproductive rights, it doesn’t sound so far-fetched to me.

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Filed under Maternal-child health, Newborns, Politics

Finger foods help prevent obesity

Filthy, yes. Fat, no.

Here’s something I’ve always felt made sense: Babies allowed to wean themselves to finger foods when they’re ready are less likely to become obese than those who continue to be exclusively spoon-fed. The simple explanation: it’s easier to learn to quit eating when you’re full if you’re the one controlling the feeding. In my experience the finger feeding phase arrives between 6 and 12 months, right at the age babies start fighting spoon feedings. (They must be reading the studies!)

Fear of choking is the concern I hear most often from parents leery of letting their babies finger feed themselves. But think of the foods typically offered as finger foods: cereal puffs, cheese, soft-cooked peas and carrots, and such. These are nearly impossible to choke on, since they quickly stick to saliva (and hair, and eyelashes, and nostrils, etc.). I challenge you – put a Cheerio in your mouth and try, try to inhale it and choke on it. You can’t, and neither can your baby.

The dangerous foods are slippery ones. Every year the leading causes of choking deaths from food are hot-dog chunks (with the skin all the way around) and whole grapes. (This usually happens to toddlers, who can grab food for themselves, and not infants, who eat what they’re given.) This is because the skin or peel makes it easy for the food object to slide to the back of the throat and block the windpipe.

Keep in mind, too, that choking and gagging are actually two very different things. Choking occurs when a solid object blocks the flow of air through the windpipe. Gagging moves food forward and away from the windpipe, and so actually protects babies from choking. It’s a good idea to take an infant CPR course so you’ll know the difference and be prepared in case of a real emergency. Most local hospitals and Red Cross chapters offer such classes.

Still, if your baby gags easily, go easy on the finger foods until a bit later. You want mealtime to be positive, and as we all have experienced at one time or another, gagging is not a pleasant sensation. The easy-gagger phase will pass in time.

In the meantime, on to finger feeding (and a jumbo under-the-high-chair ‘splat mat’!)

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Filed under Natural childbirth, Newborns, School