Association between maternal e-cigarette use during pregnancy and low gestational weight gain.

Objective: To evaluate the risk of low gestational weight gain (GWG) in women who use electronic cigarettes (e-cigarettes), combustible cigarettes, or both e-cigarettes and combustible cigarettes (dual use) during pregnancy.

Methods: We conducted a secondary analysis of the data from 176 882 singleton pregnancies in the 2016-2020 US Pregnancy Risk Assessment Monitoring System (PRAMS). Postpartum women self-reported their use of e-cigarettes and/or cigarettes during the last 3 months of pregnancy. Low GWG was defined as the total GWG less than 12.7 kg, less than 11.3 kg, less than 6.8 kg, and less than 5.0 kg (<28, <25, <15, and < 11 lb) for women with underweight, normal weight, overweight, and obesity, respectively. We used multivariable logistic regression to estimate the odds ratios (ORs) of low GWG, adjusting for confounders.

Results: In this national sample, 921 (weighted percentage, 0.5%) of women were e-cigarette users and 1308 (0.7%) were dual users during late pregnancy. Compared with non-users during late pregnancy (40 090, 22.1%), cigarette users (4499, 28.0%) and dual users (427, 26.0%) had a higher risk of low GWG, but e-cigarette users had a similar risk (237, 22.1%). Adjustment for sociodemographic and pregnancy confounders moderately attenuated these associations: confounder-adjusted ORs 1.26 (95% confidence interval [CI] 1.18-1.35) for cigarette users, 1.18 (95% CI 0.96-1.44) for dual users, and 0.99 (95% CI 0.78-1.27) for e-cigarette users.

Conclusions: Unlike combustible cigarette use, e-cigarette use during late pregnancy does not appear to be a risk factor for low GWG.