MATERNAL EXPOSURE TO ENVIRONMENTAL TOBACCO SMOKE (ETS) AND PREGNANCY OUTCOMES IN PROSPECTIVE COHORT STUDY

Abstract

Objectives Environmental tobacco smoke (ETS) inhaled by pregnant women may contain toxic compounds for adverse pregnancy outcome. This study was performed to examine the relationship between maternal exposure to ETS and adverse pregnancy outcomes (low birth weight and preterm birth) in prospective cohort study. Methods Pregnant women were enrolled at two hospital-based clinics and one local clinic in Seoul, Korea and followed for the pregnancy outcome from May 1st, 2001 to August 31st 2002. We surveyed 2,250 women who visited the hospitals at 35 gestational weeks with a self-administered questionnaire. Finally the total of 1,712 mother-infant pairs were analyzed in this study. We used multiple logistic regression analysis for analyzing the effect of maternal exposure to ETS on incidence of preterm or low birth weight, and linear regression analysis for birth weight or gestational age. Results Maternal exposure to ETS (©ø1 hours/day vs. less than 1 hour/day) during pregnancy was significantly associated with gestational age and birth weight. Maternal exposure to ETS may reduce 70g of birth weight after adjusting for potential confounders. Multiple logistic regression analysis showed that the adjusted odds ratio (AOR) of preterm birth was 1.7 (95% confidence interval (CI) 0.9, 3.3), and that of low birth weight was 2.3 (95% CI 0.9, 5.5). Conclusions This study suggests that maternal exposure to ETS during pregnancy may increase the frequency of low birth weight and preterm birth. Acknowledgement: This study was supported by the Ministry of Environment, Republic of Korea (Eco-technopia 2001).