Combustible Cigarette Use at Any Point in Pregnancy Reduces Fetal Growth

Combustible cigarette use in pregnancy has long been associated with adverse fetal outcomes. This study used data from >73,000 mother-neonate pairs to assess the effects of smoking cessation at different points of pregnancy on fetal outcomes.

• Compared with newborns whose parent did not smoke during pregnancy, mean adjusted weights of babies whose parent smoked throughout pregnancy were 135 g and 125 g lower for male and female infants, respectively.
• Quitting smoking during pregnancy reduced but did not eliminate the impact of smoking on growth parameters.
• There were no differences in growth parameters of newborns whose parent never smoked compared with those whose parent ceased smoking prior to pregnancy.

Comments: Smoking during pregnancy is harmful to the fetus. The large number of participants in this study allowed authors to demonstrate two important and actionable findings: 1) quitting smoking before pregnancy appears to eliminate the risks of nicotine and tar exposure to the fetus; and 2) while any smoking during pregnancy confers fetal risk, quitting improves outcomes in a time-dependent fashion. These findings support smoking cessation efforts that target people who are or may become pregnant as an important public health measure.

Sharon Levy, MD, MPH

Reference: Tatsuta N, Asato K, Anai A, et al. Timing of maternal smoking cessation and newborn weight, height, and head circumference. Obstet Gynecol. 2023;141:119–125.