Changes in smoking patterns during pregnancy.

This study examined trajectories of smoking during pregnancy among low-income smokers and differences on demographics, psychopathology, and smoking outcome expectancies among women with different smoking trajectories. The sample consisted of 215 urban pregnant smokers living in the United States. Results indicated four trajectories of smoking and significant changes over time within each trajectory. Persistent smokers had the highest demographic and mental health risks, reported higher craving compared to light smokers, and were more likely to endorse smoking to reduce negative affect, for state enhancement motives. Implications for intervention are discussed. The study was funded by the National Institute on Drug Abuse.