Exposure to active and passive smoking during pregnancy and severe small for gestational age at term.

Objective: The objective of this study was to assess the relationship between active smoking as well as environmental tobacco smoke (ETS) exposure and severe small for gestational age (SGA) at term in a sample of pregnant Italian women.
Methods: A case-control study was conducted in nine cities in Italy between October 1999 and September 2000. Cases of severe SGA were singleton, live born, at term children with a birth weight <or= 5(th) percentile for gestational age. Controls (10:1 to cases) were enrolled from among singleton at term births that occurred in the same hospitals one or two days after delivery of the case, with a birth weight > 10(th) percentile for gestational age. A total of 84 cases of severe SGA and 858 controls were analyzed. A self-administered questionnaire was used to assess active smoking and ETS exposure, as well as potential confounders.
Results: Multivariate logistic regression analysis showed a relationship between active smoking during pregnancy and severe SGA (adjusted odds ratio (OR) 2.10, 95% confidence interval (CI) 1.13-3.68). ETS exposure was associated with severe SGA (adjusted OR 2.51, 95% CI 1.59-3.95) with a dose-response relationship to the number of smokers in the home.