Age of smoking onset as a predictor of smoking cessation during pregnancy.

OBJECTIVE To assess age of smoking onset as a predictor of smoking cessation during pregnancy. METHODS Multivariate logistic regression analysis of cross-sectional data for 35,687 women 15-34 years old from the 2000 and 2001 National Household Survey on Drug Abuse. RESULTS Pregnant women (1805) were twice as likely to abstain as nonpregnant women (47.7% vs 23.3%). Initiation of smoking at >15 years old was associated with increased likelihood of 30-day abstinence during pregnancy (OR=1.75) after adjusting for confounders. CONCLUSIONS The earlier a woman starts smoking, the more likely it is that she will smoke during pregnancy, underscoring the need for early prevention to protect mothers and the fetuses.