Associations between electronic nicotine delivery systems and birth outcomes

Nicotine crosses the placenta and is a known teratogen. The use of electronic nicotine delivery systems (ENDS) has increased among pregnant women in the US, but there is limited knowledge about their effects on birth outcomes. We examined the associations between ENDS and cigarette use during pregnancy with birth outcomes.

We conducted a cross-sectional analysis of 57,046 respondents from 32 US states in the 2016-2017 Pregnancy Risk Assessment Monitoring System. Respondents self-reported use of ENDS and cigarettes during the last 3 months of pregnancy; this was linked with birth outcomes documented on the birth certificate, including birth weight, gestational age, small-for-gestational age, and preterm birth.

During the last 3 months of pregnancy, 0.5% of women used ENDS only, 0.8% were dual users of ENDS and cigarettes, and 8.0% used cigarettes only. In adjusted models, infants of women who used ENDS only weighed 57.8 grams less (95% CI -134.2, 18.6; p = .14) and were born 0.21 weeks earlier (95% CI -0.45, 0.03; p = .09) than infants of non-users. Infants born to dual users were 193.9 grams less (95% CI -274.9, -112.8; p < .01) and had a 1.93 higher odds of being born small-for-gestational age (95% CI 1.31, 2.83; p < .01) than infants of non-users.

Our results provide some indication that prenatal ENDS use may adversely affect birth outcomes by reducing birth weight and gestational age. Estimates were imprecise, suggesting that larger samples of ENDS users with more detailed information about patterns of use are needed.