Last week, a study generated a slew of headlines with its finding that even small amounts of alcohol during pregnancy might affect a child's later IQ. But earlier this year, another study found that moderate drinking during pregnancy didn't have any ill effects. Ultimately, while heavy drinking is clearly harmful, there may not be any reason for pregnant women to panic about light drinking — but our attitudes toward alcohol and pregnancy may not have much to do with the available science.
The study that got so much traction last week focused on children with specific gene variants that affect alcohol metabolism. Lead study author Sarah J. Lewis and her team found that among children who had one or more of these genetic variants, those whose mothers had drank any alcohol during pregnancy had lower IQ scores at age 8 than those whose moms abstained completely — children with the highest number of risky genetic variants had IQ scores about 3.5 points lower than those with none of these variants. Says Lewis, "We show that small differences in exposure to alcohol (even at low levels) is important, so I believe women should be aware that there may be a danger even when drinking small amounts."
That's in line with current guidelines from the Centers for Disease Control, which "urges pregnant women not to drink alcohol any time during pregnancy." But not all clinicians tell patients never to drink. Dr. Karin Blakemore, Director of the Division of Maternal-Fetal Medicine at Johns Hopkins, says her typical advice is that "there's no hard evidence that a little tiny bit of very light drinking causes any problems to the child." She adds, "Most pregnant women drink very little or not at all. They may have something on occasion, and we feel that that is probably safe."
Lewis's study, says Blakemore, doesn't change that. She notes that for their analysis, the study authors grouped together women who had less than one drink a week with those who had up to six, when those who had almost no alcohol may have had very different effects than those who drank nearly daily. (Lewis says, "We decided not to break the data down into smaller groups because this would reduce our power to detect an effect.")
Blakemore adds that the differences in IQ the study authors found, while statistically significant, are "clinically not significant" — they're unlikely to produce measurable effects on a child's life. "It's really not a study that should alter what we currently tell our patients," she says.
Attitudes toward drinking while pregnant aren't the same worldwide — biological anthropologist Pamela Stone, coauthor of the book Childbirth Across Cultures says, "If we were in France right now, the idea of having a glass of wine while you're pregnant would be totally normal." And doctors' own preferences may come into play. She says there's a saying that "if you go to a doctor who skis and you're pregnant, he'll say you can ski. If he doesn't ski, he'll say you can't ski." The same may be true with drinking.
Nonetheless, the idea that any drinking during pregnancy is hazardous is pretty firmly entrenched in many people's minds, at least in the U.S. Claudia Malacrida, a sociologist who studies gender and motherhood, says that these days when it comes to alcohol and pregnancy, women "police themselves and they police one another, and they're seen as normal to do that." In the past, women could (perhaps half-jokingly) point to photos of their pregnant moms sipping martinis and note that they came out fine. But now prohibitions on alcohol have been around long enough, says Malacrida (who's in her fifties), that "my daughter's generation can't talk about 'Mom and the martini' because there are no pictures of me like that." The notion that even small amounts of alcohol are dangerous might be contested in studies (like the one from this summer), but in general, it's totally accepted.
And she suspects that restrictions on pregnant women's behavior — not just on alcohol but on food, activity, medications, stress — are likely to get more numerous rather than less. She blames the large and growing market for pregnancy advice of all kinds, "and a lot of people are making a lot of money telling other people what to do," she says. The result is a feeling among moms that "if anything goes wrong, it's your fault."
Nobody advocates heavy drinking during pregnancy; it's awareness of the dangers of fetal alcohol syndrome that led pregnant women to avoid alcohol in the first place. And of course, many may simply prefer to do so. But Blakemore points out that many women don't know they're pregnant right away, and they shouldn't worry unduly if they've had a few drinks before they found out. "You don't scare the pants off a pregnant woman if you're not fairly sure that something's dangerous," she says. "They have enough to worry about."