Keira Knightley, who is nominated for an Academy Award for Best Supporting Actress for her role in “The Imitation Game,” would love nothing more than a cocktail right now. Alas, the 29-year-old actress is pregnant with her first child.

“I can’t drink,” Knightley told Ellen DeGeneres on her talk show recently. “I’m up for an Oscar and I can’t drink at the Oscars.” She added: “I went to the doctor—you have to get lots of doctor check-ups when you’re pregnant—and she asked if I had any questions. And I said, “Yes! When can I drink? Please! I just want a margarita.”

I can relate to Knightley’s plight: Outside of a sip or two, I abstained from drinking throughout my entire pregnancy. Did I miss indulging in my favorite Pinot Noir and beloved martinis? Sure. But I wasn’t willing to take any risks, however small they might be.

Some may feel that Knightley and I are being overly cautious by having a Prohibition-style pregnancy rather than indulging in a glass or two now and then. And they’re likely correct. But ask any reputable obstetrician what amount of light to moderate drinking during pregnancy is officially considered safe, and you’ll hear the following: “The real answer is we don’t know,” Iffath Hoskins, MD, a high-risk OB-GYN at NYU Langone Medical Center, told YouBeauty.

Doctors do know that frequent binge drinking (having four or more drinks on one occasion) and particularly, chronic, heavy drinking such as with alcohol addiction, is linked to fetal alcohol syndrome, which can cause a baby to develop multiple physical and cognitive problems, including facial deformities and brain damage. But the jury is still out when it comes to the safe limits of light drinking, such as having a glass or two here and there.

Explained Hoskins: “How much is okay and what is the tipping point of what’s not okay? Nobody really knows.” It’s likely safe to have one or two glasses of wine per week, she said. “But if you have three glasses of wine at a wedding, it doesn’t mean you’re a horrible person and are damaging your baby. It’s not [the same as] having alcohol week after week after week. There’s no shame or harm in periodical, social drinking at an event.”

While some pregnant women may abstain from drinking alcohol until they reach the third trimester, thinking that the “goose is cooked,” Hoskins pointed out that the fetus’ brain, as well as other organs, are still growing and developing then so there isn’t a risk-free period. “It’s not so much about the first or the third trimester,” she said, “it’s the quantity of drinking and drinking chronically that’s the issue.”

For moms-to-be, Hoskins recommends having an honest conversation with your health care provider about how much booze you’re drinking each week. “Don’t underreport it,” she says. “Better to say I drink three to four glasses of wine every single week and for your doctor to know.”

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