Fetal Growth Following Electronic Cigarette Use in Pregnancy

Abstract

Electronic cigarette (e-cig) use in pregnancy is common, but potential effects on fetal development are largely unknown. This study's goal was to examine the association between e-cig exposure and fetal growth. Data were extracted from medical charts in this single-site retrospective study. The sample, excluding those with known tobacco, alcohol, illicit drug, opioid, and benzodiazepine use, contained women who used e-cigs throughout pregnancy and non-e-cig user controls. Fetal size measurements from second- and third-trimester ultrasounds and at birth were expressed as percentiles for gestational age. Following adjustment for confounding factors, in the second trimester, only femur length was significant, with an adjusted deficit of 11.5 percentile points for e-cig exposure compared to controls. By the third trimester, the femur length difference was 28.5 points, with the fetal weight difference also significant (17.2 points). At birth, all three size parameter differences between groups were significant. Significant size deficits were predicted by prenatal e-cig exposure, becoming larger and impacting more parameters with increasing gestation. While additional studies are warranted to confirm and expand upon these findings, this study adds to emerging data pointing to specific harms following e-cig exposure in pregnancy and suggests that e-cigs may not be a "safer" alternative to combustible cigarette smoking in pregnancy.

Keywords: birth size; electronic cigarettes; in utero growth; pregnancy smoking; vaping.