[Maternal smoking during pregnancy and anthropometric measurements of newborns: a population-based study in southern of Brazil].

This cross-sectional study aimed to investigate the prevalence of maternal smoking during pregnancy and its impact on anthropometric measurements of newborns. A standardized questionnaire was applied to all pregnant women admitted for delivery in the maternity units in Rio Grande, Rio Grande do Sul State, Brazil, in 2007. Measurements were taken of the newborns' weight, length, and head circumference. Prevalence rates were 23% for maternal smoking during pregnancy and 29% for exposure to environmental tobacco smoke. After adjusting for potential confounding factors, compared with those whose mothers never smoked, newborns whose mothers smoked throughout pregnancy showed average decreases of 223.4 g in birth weight (95%CI: 156.7;290.0), 0.94 cm in birth length (95%CI: 0.60;1.28), and 0.69 cm in head circumference (95%CI: 0.42-0.95). In conclusion, prevalence of maternal smoking during pregnancy was high in this municipality. Maternal smoking during pregnancy was inversely associated with birth weight, length, and head circumference.