Every pregnant woman in the country gets the same stern warning: Don't drink any alcohol.
But many of them still have a glass of wine at dinner, and they do it with the approval of their obstetrician/gynecologists.
So, what's the real deal? Is it dangerous to drink if you're expecting?
The country's medical establishment has long preached to pregnant women that they should avoid alcohol out of fear that it may harm the fetus.
But many obstetricians around the country counsel their patients that it's OK to have a few glasses of wine per week. And some of their patients take that advice -- more than 12 percent of pregnant women are social drinkers, according to government studies.
That discrepancy was exposed again last week when Oscar-winning actress Rachel Weisz, who recently gave birth to her first child, told fans that it was "fine" for expectant mothers to have a glass of wine after the first trimester.
The "Constant Gardener" star's recent comments caused an uproar among medical experts, some of whom condemned her advice as irresponsible.
In recent years, other celebrities such as Gwyneth Paltrow and Britney Spears have made headlines when they were photographed drinking while pregnant. Commentators were quick to call them unfit mothers-to-be.
"If you're pregnant and you drink alcohol in any amount, you take a risk that it could be causing harm to the fetus," said Tom Donaldson, the president of the National Organization on Fetal Alcohol Syndrome.
Because alcohol is a neurotoxin, it has the capacity to interfere with the development of the fetus and can be even more harmful than crack cocaine or other drugs, Donaldson explained.
"Why play Russian Roulette with your baby's health?" he said. "We say abstain from alcohol if you're pregnant or could be pregnant."
Similarly, the American Medical Association and the American College of Obstetricians and Gynecologists strongly recommend that expectant mothers avoid any alcohol during their pregnancy, warning that it could lead to mental and physical defects.
Concerned that the lack of public consensus on the issue was leading to risky behavior, then-Surgeon General Richard H. Carmona reissued a 25-year-old advisory last year about the dangers of drinking while pregnant.
Those stern warnings didn't dissuade Alexandra Atkins, a 38-year-old mother of two who lives in Manhattan, N.Y.
"I definitely drank once in a while, a glass of wine or a beer," she said. "My OB-GYN said it was OK to have an occasional drink -- and I have a healthy boy and girl."
Kate Licatta, a mother of three in New Canaan, Conn., says that her doctor said it was OK to have an occasional glass of wine.
"So I did, and I was less cautious with my second," Licatta said. "Not that I was taking it down every day with my third, but I drank twice a month, typically just wine or beer."
Plenty of obstetricians agree, arguing that it's safe to have a few glasses of wine or beer per week, as do some governments, including the British Health Ministry, which says that pregnant women can drink one or two units of alcohol -- glasses of wine, shots of liquor -- once or twice a week.
Robert K. Zurawin, a gynecologist at the Baylor College of Medicine in Houston, says that it's OK for a pregnant woman to have an occasional drink.