Moderate drinking may not affect women’s fertility

Although current U.S. guidelines encourage women to stop drinking while trying to get pregnant, a new Danish study suggests giving up alcohol may not be necessary for improving the chances of conceiving.

Women in the study who drank up to 14 drinks per week were just as likely as those who didn’t drink at all to get pregnant in the first month of trying.

“We tell women not to eat seafood, or consume too much caffeine when trying to conceive,” Dr. Christina Porucznik of the University of Utah in Salt Lake City told Reuters Health by phone. “So it’s reassuring to know that if they drink a small amount of alcohol, it’s not going to prevent them from getting pregnant.”

But she cautions that women who think they might be pregnant should still limit their alcohol intake.

“In this study, they focus on drinking before you conceive. But we know that alcohol can be harmful for the fetus,” said Porucznik, who studies the effects of the environment on pregnancy but who wasn’t involved in the current research.

Lead author Dr. Ellen Mikkelsen, senior researcher in the Department of Clinical Epidemiology at Aarhus University in Denmark, didn’t respond to a request for comment.

The researchers analyzed national survey data collected from 2007 through 2016 from 6,120 Danish women, ages 18 to 40, who were in stable relationships with men and were trying to conceive.

As part of the surveys, women were asked to consider their alcohol intake during the previous month and to report on average how many servings of alcohol they consumed weekly.

The definition of “one serving” varied depending on the type of drink: beer (330 mL, or about 11 oz), red or white wine (120 mL; about 4 oz), dessert wine (50 mL; about 2 oz), and hard liquor (20 mL; about 1 oz).

Researchers also accounted for risk factors including age, menstrual cycle regularity, frequency and timing of sex, caffeine intake and last method of birth control. But they didn’t examine the alcohol habits of male partners.

By the end of the study, 4,210 women, or 69 percent, had gotten pregnant.

Fecundability – the probability of getting pregnant in a single menstrual cycle – was similar as long as women consumed less than 14 servings a week of hard liquor, the researchers found.

Consumption of beer and wine made “no appreciable difference” to fecundability no matter how much women consumed, they found.

The study wasn’t designed to examine the effects of binge drinking on fertility, the authors note in The BMJ.

Dr. Lynn Westphal, who studies fertility issues in women at Stanford University Medical Center in California but was not involved with the study, was not surprised by its findings.

“It’s common knowledge that women get pregnant even while drinking,” she said.

For women who want to conceive, it’s most important to think about living a healthy lifestyle, said Westphal.

“It’s a good time for women to cut back on alcohol, especially for those who drink heavily,” she said.

“If they’re aware of their drinking habits, they’ll hopefully be mindful of stopping as soon as they get pregnant.”