Study details

For the study, researchers analyzed 2021-2024 data from the national Behavioral Risk Factor Surveillance System, which is an annual state-based survey of health behaviors. The study included responses from women ages 18 to 49 who self-reported as pregnant. Information on trimester was not collected.

The researchers found that 15.2% of pregnant women reported drinking in the past 30 days, while 4.9% reported binge drinking and 2.2% reported heavy drinking. Current drinking was defined as one or more alcoholic drinks in the past 30 days while binge drinking was defined as four or more drinks on at least one occasion in the past 30 days and heavy drinking was defined as eight or more drinks in a one-week period in the past 30 days.

Among the pregnant women who reported current drinking, 33.2% also reported binge drinking and 14.7% reported heavy drinking, the study found.

The researchers also found that some groups of women were significantly more likely to drink during pregnancy than others. For example, unmarried pregnant women had roughly twice the prevalence of current drinking, binge drinking, and heavy drinking than married women.

Meanwhile, pregnant women who reported frequent mental distress also had roughly twice the prevalence of current drinking and binge drinking, and three times the prevalence of heavy drinking compared to those who didn't report frequent mental distress.

The researchers also noted significant regional differences, which generally aligned with drinking trends in the overall U.S. population. For example, 19.9% of women in New England reported drinking while pregnant compared to 10.4% in the mid-South and 12.4% in the Mountain West.

The authors noted some limitations to their study, including the possibility that respondents may have become pregnant during the 30 days prior to the survey and as a result their reported alcohol use may have been prior to pregnancy.

"Recommended clinical interventions include routine screening for alcohol consumption and mental health conditions, brief behavioral counseling, and referral to specialized services," the authors wrote. "Community-level approaches that include providing information about outcomes associated with alcohol consumption during pregnancy or address alcohol consumption among the general population might also help reduce prenatal alcohol exposure and prevent its associated adverse health outcomes."

Nikki Zite, an ob/gyn with the University of Tennessee Graduate School of Medicine who was not involved in the study, said that the increase in drinking while pregnant is "concerning."

"Media coverage and public health campaigns that historically focused on the dangers of alcohol use in pregnancy have shifted to recommendations related to other substances — such as opioids or marijuana," Zite said. "Hopefully this MMWR will remind providers and public health officials that awareness, screening, and support for those that are at increased risk of or already consuming alcohol during pregnancy is still needed despite competing priorities."