According to new research, drinking alcohol is most damaging to fetal development during the first trimester, with the potential to lead to physical deformities as well as behavioral and cognitive symptoms.
The latest study, published in the journal Alcoholism: Clinical & Experimental Research, followed 992 women over a nearly 30 year period, tracking their alcohol and substance intake every three months while they were pregnant. As Alice Park of Time reports, every drink pregnant mothers consumed between their 43rd and 84th days of pregnancy added a 16 percent chance that their babies would be born smaller than average. These infants were also more likely to incur birth defects such as abnormally small heads and thin upper lips typical of fetal alcohol syndrome.
It's compelling, even frightening, evidence. But how much stock should we place on a single study of 1,000 people?
In 2010, a more expansive survey done in the United Kingdom came to a less harrowing conclusion. Following more than 18,500 children born between 2000 and 2002, scientists found no evidence of harm from having a couple of drinks a week during pregnancy. Said Fred Bookstein, an applied statistician studying fetal alcohol spectrum disorders at the University of Washington and the University of Vienna, to Discovery News:
"It is no longer valid to argue that we don't know enough about low-dose drinking during pregnancy or that the known effects of binge drinking may penetrate to low-dose drinkers somehow," said Bookstein. "There is no detectable risk associated with light or moderate drinking during pregnancy."
So which is it? While everyone knows heavy boozing is bad for babies, cultural attitudes vary when it comes to the occasional glass of merlot. In the U.K., where a third of women report drinking at some point during their pregnancy, official guidelines mandate that they "should not drink more than 1 to 2 units of alcohol once or twice a week and should not get drunk." Meanwhile, here in the States, pregnant women are often pressured to abstain completely, getting turned away by liquor store clerks even when they're not planning on drinking.
In the end, it comes down to personal choice. But for mothers-to-be who might have imbibed before they found out they were pregnant, there's some comfort in knowing that a glass of wine probably isn't going to do lasting damage. Just don't make a habit of it. As Dr. Michael Katz, professor emeritus of pediatrics at Columbia University, said to ABC News: "You can walk on a railroad track and not be hit by a train, but that doesn't mean it's a safe thing to do."