Drinking During Pregnancy in the U.S., 2015–2017: One in Nine, and a Third of Them Binge

No amount of alcohol is known to be safe during pregnancy. Drinking while pregnant can cause fetal alcohol spectrum disorders (FASDs) — birth defects involving central nervous system impairment, behavioral disorders and impaired intellectual development, which can later make school and work harder. A recent study in four U.S. communities found FASDs in 1.1%–5.0% of first-graders. Drinking may also raise the risk of miscarriage, stillbirth and other poor pregnancy outcomes.

A CDC team (Clark H. Denny, Cristian S. Acero, Timothy S. Naimi and Shin Y. Kim) measured how many pregnant women still drink.

How the data were collected

The Behavioral Risk Factor Surveillance System (BRFSS) is a landline and cellphone survey, reached by random-digit dialing, of civilian, noninstitutionalized adults aged 18 and older. All states and participating U.S. territories run it with CDC.

• Sample: 6,814 women aged 18–44 who said they were pregnant, from all 50 states and the District of Columbia, 2015–2017. How far along each pregnancy was was not recorded.
• Response rate: annual medians of 45.8% to 47.0%.
• Current drinking: at least one drink in the past 30 days.
• Binge drinking: four or more drinks on at least one occasion in the past 30 days.
• Intensity: the largest number of drinks on any one occasion in that month.

Results were weighted to state populations and combined into national estimates, with adjusted prevalence ratios (aPRs) accounting for age, race/ethnicity, education, employment and marital status.

What they found

• 11.5% of pregnant women reported current drinking and 3.9% reported binge drinking — roughly one in nine drinking, and about a third of those binge drinking.
• Women who binge drank did so an average of 4.5 times in the month, with an average of 6.0 drinks at their heaviest.
• Unmarried women were more likely than married women to drink and to binge drink.

* Possibly unstable (relative standard error 0.2–0.3). "Suppressed" means the relative standard error was above 0.3. Source: CDC, MMWR.

Compared with earlier years

Both measures were slightly higher than in 2011–2013, when 10.2% of pregnant women reported drinking and 3.1% binge drinking. Binge frequency was about the same (4.6 episodes then), but intensity fell from 7.5 drinks to 6.0.

The authors suggest the higher rates among unmarried women may reflect the financial stress of being the sole provider and a lack of social support. High blood alcohol levels may be especially harmful to a developing brain, and can occur before a woman knows she is pregnant; women who binge drink before pregnancy are more likely to drink and binge drink during it.

Caveats

1. Answers are self-reported, so drinking during pregnancy is probably underreported.
2. Response rates were under 50% every year, which can bias results.
3. Some estimates were unstable or suppressed because of large standard errors.
4. Some pregnancies were likely not yet recognized at interview; on average women learn they are pregnant at 5.5 weeks.
5. Trimester was not recorded, and drinking is more common in the first trimester than later.

What helps

• Community measures recommended by the Community Preventive Services Task Force: regulating how many places sell alcohol in an area (through zoning, licensing or state alcohol control), commercial host liability laws, and limits on hours and days of sale.
• Screening and brief counseling: the U.S. Preventive Services Task Force recommends it in primary care for all adults 18 and older, pregnant women included; any drinking in pregnancy counts as unhealthy use.
• Obstetric care: the American College of Obstetricians and Gynecologists recommends screening all women seeking obstetric-gynecologic care, telling patients no level of alcohol is known to be safe in pregnancy, and advising women who are or might be pregnant not to drink.

Sources

Based on Denny CH, Acero CS, Naimi TS, Kim SY, "Consumption of Alcohol Beverages and Binge Drinking Among Pregnant Women Aged 18–44 Years — United States, 2015–2017," MMWR, Centers for Disease Control and Prevention; a work of the United States government in the public domain.