Paternal smoking and birthweight in Shanghai.

OBJECTIVES. Although maternal active smoking has been established to be associated with fetal growth retardation, evidence of an effect of environmental tobacco smoke exposure on birthweight is still limited and inconclusive. This study addressed the relationship between prenatal environmental tobacco smoke exposure and birthweight and fetal growth retardation in Shanghai, China. METHODS. Data on 1785 full-term live-born normal infants of nonsmoking mothers were used from the Shanghai Birth Defects and Perinatal Death Monitoring conducted between October 1986 and September 1987. Environmental tobacco smoke exposure was defined as exposure to paternal smoking. RESULTS. Infants with environmental tobacco smoking exposure were, on average, 30 g lower in birthweight than nonexposed infants, after adjustment for gestational age, parity, maternal age, and occupation. CONCLUSION. Consistent with previous research, this study suggests that environmental tobacco smoking exposure may have a modestly adverse effect on birthweight.