Tara Haelle via www.forbes.com
It’s been just over four decades since fetal alcohol syndrome (FAS) was first described, yet contradictory advice to women about drinking any alcohol at all during pregnancy continues to confuse and frustrate women. Is one glass a day okay? Or once a week maybe? One a month? One time ever, in 40 weeks of gestation?
In a new clinical report, the American Academy of Pediatrics makes the issue crystal clear from their perspective, based on the available research to date: no amount of alcohol is safe to drink during pregnancy, period. No lower threshold of safe consumption has ever been established, and prenatal alcohol alcohol remains the “leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities,” the AAP states.
I would once have found this conclusion from the evidence base misleading and draconian. After all, women in Europe drink a little wine with dinner during pregnancy, right? And haven’t lots of studies found that women who drink very lightly during pregnancy — say, no more than a glass a week — have children that turn out just fine or even a little better off than their peers? Yes, many studies have found this result — I read dozens of them while researching the book on science-based parenting that I cowrote with Emily Willingham. In fact, I started researching that section trying to prove myself wrong because I knew I was biased toward believing that a glass here and there couldn’t hurt much, if at all. The thing is, while poring over dozens of studies, I actually succeeded in convincing myself that I was wrong. The evidence showed me I was.
The problem with the many studies showing no effect from very light drinking on children is that the women most likely to drink lightly also tend to be more educated women with higher household incomes. The deck is already stacked in favor of their children, who are already more likely to have better cognitive, behavioral and health outcomes than children born to parents with less education, lower incomes or otherwise fewer resources. The majority of these studies attempt to “control” for education and income — that is, make adjustments in the analysis to statistically account for those differences. But no amount of math can overcome the residual confounding that occurs in these studies because women who drink very lightly during pregnancy are so fundamentally different from women who drink more or women who abstain altogether.
The other problem with those studies, I discovered while researching the book, is that they often lack the precision to identify potential effects of alcohol exposure. The harm that can come from alcohol during pregnancy isn’t limited to fetal alcohol syndrome. FAS occurs along a spectrum, and children without physical indications of diagnosed FAS can still exhibit the cognitive and behavioral effects of alcohol exposure in the womb. Perhaps it’s just one IQ point a child doesn’t have (putting aside all the problems with IQ as a measure) because of exposure to several glasses of Merlot during pregnancy. That’s not a difference that will easily show up, if at all, in a study with a couple tests, but the absence is still there.
Furthermore, effects of prenatal alcohol exposure may not show up until adolescence, yet the vast majority of studies investigating light drinking during pregnancy only follow children until toddlerhood or occasionally the preschool or early elementary school years. One series of studies, still ongoing from Denmark, has only assessed children up to 5 years old. Another study of more than 5,000 children did evaluate children up to age 14, but few have done so, and there is disagreement among researchers over which assessments are best for identifying possible problems.
Some things have been well-established for many years: alcohol during the first trimester can have more harmful effects than alcohol during later trimesters. (This fact is especially problematic considering that half of all pregnancies in the US are unplanned.) The type of alcohol — beer, wine or liquor — is irrelevant. And binge drinking — having more than a couple drinks in one sitting — has worse effects on a fetus. Basically, the more a woman drinks while pregnant, the worse the effects on her child usually are.
Is having a single drink one time during 40 weeks of incubating your little critter going to have a major effect on them? No, probably not, or at least we don’t have a single study saying so. (That’s also why women shouldn’t panic if they found out they were pregnant after a binge; the anxiety caused by worry could, over a pregnancy, end up having greater effects than the alcohol, and what’s done is done.) But women and their metabolism differ, as do the fetuses they’re incubating. There is no way to establish what is potentially “safe” and what is not for one women’s child or another’s. Alcohol is a neurotoxin that crosses the placenta. If a pregnant woman drinks it, her fetus absorbs it — but without an equivalent ability to metabolize it. The only way to be absolutely certain your child does not experience lifelong negative effects from alcohol exposure is to abstain while trying to conceive or not to drink as soon as you find out your pregnant.