The Effect of Prenatal and Postnatal Environmental Tobacco Smoke Exposure on Infant Health

Abstract

Objectives: Environmental tobacco smoke (ETS) is a common indoor pollutant. Fetuses, neonates, and young children are most at risk from ETS exposure. In this study, we evaluated the relationship of exposure to prenatal and postnatal ETS to birth outcomes (including preterm delivery [PTD], low birth weight [LBW], and small for gestational age [SGA]) and child health outcomes (including emergency visits and hospitalizations). Methods: In this pilot project of the Taiwan Birth Cohort Study, we used a self-reported questionnaire. We interviewed 2,048 mothers 6 months after their deliveries and recruited 1,725 mother-newborn pairs. We analyzed the association of adverse birth outcome and child health with exposure to prenatal and postnatal ETS using regression models, and analyzed relationships between birth outcome and child health and frequency of exposure to prenatal and postnatal ETS using the test for trend. Results: We found a significant association between exposure to ETS during pregnancy and PTD, SGA, emergency visits, and hospitalizations of infants. In addition, infant exposure to ETS via maternal smoking during or after pregnancy contributed to significant crude relationships between LBW, SGA, emergency visits, and hospitalizations, but these relationships were completely explained by the effects of covariates other than SGA. We also observed that paternal smoking during or after pregnancy dose-dependently increased hospitalization risks of infants. Moreover, the mean adjusted BW decrement was 222.3 g in newborns exposed to ETS from maternal smokers. Conclusions: Although maternal smoking risks are very low in Taiwan, prenatal or postnatal ETS exposure still impacts children. Our findings highlight the emerging challenge of prenatal and postnatal ETS exposure to the public health.