Association Between Acetaminophen Exposure in Pregnancy and Adverse Birth Outcomes [ID 751]

INTRODUCTION: It is estimated that 65% of women use acetaminophen during their pregnancy in the United States. Mounting evidence has indicated that acetaminophen exposure in pregnancy may affect fetal development, culminating in a consensus statement in Nature calling for increased vigilance. This prospective population study aims to understand the association between maternal acetaminophen use and adverse birth outcomes. METHODS: The population includes women aged 15–45 from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be. First-trimester pregnant women were enrolled across eight clinical sites. Linear and logistic regression models quantified the associations between maternal acetaminophen use and adverse birth outcomes. RESULTS: In the population (n=8,930), 1,881 (21%) women aged 15–45 used acetaminophen during their pregnancy. Women who used acetaminophen were similar in age, education status, and prenatal tobacco use (values of P >.05), but differed in race and prenatal alcohol use (values of P <.01), compared to women who did not use acetaminophen. In crude linear regression, acetaminophen exposure was not associated with birth weight ( P >.05); however, after accounting for confounders, it was associated with a decrease of 27.1 g in birth weight (95% CI, −51.0, −3.1). Acetaminophen exposure was not associated with preterm birth (odds ratio 0.94; P >.05). CONCLUSIONS/IMPLICATIONS: These initial results suggest that acetaminophen exposure may be associated with decreased birth weight, although not with preterm birth. Additional analyses to estimate the association between acetaminophen use and other important birth outcomes including congenital anomalies are underway.