For decades, the message from the medical community has been clear: Alcohol and pregnancy do not mix. But if you love a glass of merlot with dinner or an IPA after work, questions arise. What about a glass of wine here and there? Or half of a beer? Does a celebratory sip of champagne really count?

Despite near-constant warnings from organizations such as the CDC, U.S. Surgeon General, and American Academy of Pediatrics—not to mention a vast library of research on the harmful effects of alcohol use during pregnancy—many women still partake. According to 2013 data from the CDC, one in 10 pregnant women reported having a drink in the past 30 days, while one in 33 even reported binge drinking.

Plus, some research has suggested that a little alcohol is OK: One Danish study published in 2012 found that low to moderate consumption of alcohol throughout pregnancy had no measurable effect on the babies in question when they were tested five years later.

And a 2013 study found that light drinking during the first trimester had no impact on the behavior and development of over 10,000 7-year-olds. So is it really that bad?

The Bottom Line

Yes, it really is that bad, experts say. Despite any outlier evidence and anecdotal advice, any alcohol during pregnancy is still a hard and fast no. Period. (And drinking isn’t any less risky just because it’s your birthday or New Year’s Eve.)

“It’s not at all controversial for me because there’s only one answer: There is no safe low threshold of alcohol known in pregnancy,” says Alyssa Dweck, M.D., OB/GYN, assistant clinical professor of medicine at the Mount Sinai School of Medicine.

As she points out, some women are worried about getting their nails done while pregnant, but they’re wavering about drinking alcohol—which just doesn’t add up.

Think of it this way: When you drink, your baby drinks—and alcohol can be a toxic substance in utero. Introducing alcohol into the fetal environment (any amount, any type of alcohol, at any time) may cause brain damage, birth defects, or serious behavioral and learning disorders, such as autism or attention deficit disorder (ADD). And although many babies affected by alcohol may not have any physical birth defects, the impact of alcohol will become evident in later childhood or adolescent.

Why take any additional chances or risks with something that’s already so risky?

Niket Sonpal, M.D. assistant clinical professor of medicine at Touro College of Medicine, agrees: “From the minute you know to the minute you deliver, no alcohol,” he says. “Why take any additional chances or risks with something that’s already so risky?”

As for rumors that a glass of wine as you approach the due date can help you relax and speed up labor? Those are nothing more than old wives’ tales, our experts say. Each phase of pregnancy is critical to fetal development, so even in those final days, alcohol is a no-go.

“The fetus’s brain continues to develop in utero during late term, and there is no lower limit of alcohol that has been determined to be safe, either pre-conception or during pregnancy,” Dweck says. And it’s doubtful we’d have a better idea any time soon, since many women underreport the amount they drink in studies and randomly assigning pregnant women to drink would be unethical, Dweck adds.

Finally, if you’re trying to get pregnant, you may want to pay extra attention to your cycle (we assume you probably are anyway). “It’s best to avoid alcohol from the time of ovulation for ladies who aren’t yet pregnant but hoping to be,” Dweck says.

If you have alcohol and then find out you are pregnant, avoid drinking from that point on. “I say this out of an abundance of caution because, again, there is no known minimum amount of alcohol considered to be safe in pregnancy,” she adds.