Purpose: Despite high rates of spontaneous and assisted smoking cessation during pregnancy, postpartum maintenance is disappointingly low. Predictors of return to smoking remain unclear, thus limiting the development of interventions that could protect the health of women and their children. This study followed women who had participated in a prenatal smoking cessation intervention trial and successfully stopped smoking to address two aims: (1) describe the probability of relapse in confirmed quitters during the first 6 months after the birth, and (2) identify factors that increase relapse.
Design: Prospective design during pregnancy and retrospective report at 6 months postpartum used survival analysis with return to smoking as the dependent variable and the Cox proportional hazards regression technique.
Measures: Questionnaires were used at the first prenatal visit and telephone interviews at the 26th week of pregnancy and 6 months postpartum. Nonsmoking after the 20th week was measured by urine cotinine tests (m = 3); nonsmoking postpartum was measured by retrospective self-report.
Setting: The setting was an HMO-based group practice in Los Angeles.
Subjects: Subjects were white, black, and Hispanic women (n = 127) available for follow-up.
Results: The proportion of the sample classified as relapsers at 6 months postpartum was 62.9%. The final model identified the following risk factors for smoking: taking puffs in late pregnancy and having friends who smoke at the first prenatal visit, less confidence in mid-pregnancy that they could maintain nonsmoking postpartum, and a partner who smokes postpartum.
Conclusions: Intervention should begin in late pregnancy, and smoking networks, including partner smoking, should be addressed.