OBJECTIVES: To evaluate the effect of a provider counseling and office systems intervention in obstetric, pediatric, and Special Supplemental Nutrition Program for Women, Infants and Children (WIC) clinics on smoking and relapse rates in pregnant and postpartum women.

METHODS: Five community health centers were randomized to special intervention (SI) or usual care (UC). Subjects (n =601) were current smokers or had quit with pregnancy. Prenatal and postpartum interviews assessed smoking status and related factors. Data were collected between May 1997 and November 2000.

RESULTS: There was a statistically significant difference in 30-day abstinence rates between SI (26%) and UC (12%) conditions at the end of pregnancy among women who had not quit spontaneously with pregnancy (odds ratio [OR]=2.57, p =0.05). This effect remained at 1 month postpartum but was lost at 3- and 6-month postpartum follow-ups.

CONCLUSIONS: Brief interventions delivered by healthcare providers during routine prenatal care increased smoking abstinence during pregnancy among women who did not quit spontaneously. Interventions extended into postpartum care did not affect relapse and smoking rates postdelivery.