Maternal smoking during pregnancy and risk factors for cardiovascular disease in adulthood.

Objective: This study was aimed at assessing the effect of maternal smoking during pregnancy on metabolic cardiovascular risk factors in early adulthood in a Brazilian birth cohort, after controlling for possible confounding variables and health behaviors in early adulthood.

Methods: In 1982, the maternity hospitals in Pelotas, southern Brazil, were visited and all births were identified. Those livebirths whose family lived in the urban area of the city were studied prospectively. In 2004-2005, we attempted to follow the whole cohort, the subjects were interviewed, examined and blood sample was collected. The following outcomes were studied: blood pressure; HDL cholesterol; triglycerides; random blood glucose and C-reactive protein. To explore the effect of maternal smoking, we adjusted the coefficients for the following possible mediators: perinatal factors (low birthweight and preterm births); adult behavioral factors (physical activity, dietary pattern, intake of fat and fiber, and tobacco smoking) and adult anthropometry (body mass index and waist circumference).

Results: In 2004-2005, we interviewed 4297 subjects, with a follow-up rate of 77.4%. The only significant finding in the unadjusted analyses was lower HDL cholesterol among females. After adjustment for lifestyle variables in early adulthood, birthweight and waist circumference, the difference in HDL levels between offspring of smokers and non-smokers reduced from -2.10mg/dL (95% confidence interval: -3.39; -0.80) to -1.03 mg/dL (-2.35; 0.30).

Conclusion: Evidence that maternal smoking during pregnancy programs offspring metabolic cardiovascular risk factors are scarce, and reported associations are likely due to postnatal exposure to lifestyle patterns.