Sex differences in the association between prenatal smoking and decreased birthweight, and intensive health care of the neonate.

Gender-specific associations between prenatal smoking and birthweight, and neonate intensive health care were studied. Cross-sectional data from 11,583 newborns in the continuous National Health and Nutrition Examination Survey (NHANES) 2003-2008 early childhood data sets were used. Change in infant birthweight and likelihood of receiving neonatal intensive care by prenatal smoking exposure were assessed. Multivariable regression models were used to assess the influence of prenatal smoking on birthweight and likelihood of receiving intensive neonatal health care. Compared with infants from nonsmoking mothers, prenatal smoking associated with significant decrease in infant birthweight, -203.0 g ± 32.5, P < 0.001. The change in birthweight differed between infant boys, -220.2 g ± 44.5, and girls, -184.1 g ± 38.8. Newborns exposed to prenatal smoking were more likely to have low birthweight, odds ratio 1.46, P < 0.03, and to receive neonatal intensive health care, odds ratio 1.20; P < 0.04. It is imperative that prenatal counseling emphasizes prenatal maternal smoking.