Reducing the Prevalence of Alcohol-Exposed Pregnancies in the United States: A Simulation Modeling Study

Public health efforts to prevent alcohol-exposed pregnancies (AEPs) primarily focus on promoting abstinence from alcohol among women if pregnant or seeking pregnancy and using effective contraception to prevent unintended pregnancies if consuming alcohol. Little is known about how programs to improve adherence to these recommendations would affect the prevalence of AEPs.

We developed an individual-based simulation model of US women of reproductive age to project the prevalence of AEPs under different public health strategies. The model varies each woman's risk of an AEP over time depending on fertility, contraceptive use, awareness of pregnancy, sexual activity, and drinking patterns. We used the 2013-2015 National Survey on Family Growth data set to parameterize the model.

We estimate that 54% (95% uncertainty interval: 48%-59%) of pregnancies that result in a live birth in the United States are exposed to alcohol, 12% (10%-15%) are ever exposed to ≥5 alcoholic drinks in a week, and 3.0% (1.3%-4.2%) to ≥9 drinks. Unintended pregnancies (either due to contraceptive failure or sex without contraceptives) account for 80% (75%-87%) of pregnancies unknowingly exposed to alcohol. We project that public health efforts that focus only on promoting alcohol abstinence among women who are aware of their pregnancy or seeking pregnancy could reduce the prevalence of AEPs by at most 42% (36%-48%). Augmenting this strategy with efforts to avert unintended pregnancies could yield an 80% (73%-86%) reduction in the prevalence of AEPs.

Promoting alcohol abstinence among women who are aware of their pregnancy or seeking pregnancy offers limited potential to reduce the prevalence of AEPs. Programs to avert unintended pregnancies are essential to achieve more substantial reductions in AEPs in the United States.