Maternal smoking and the timing of WIC enrollment.

OBJECTIVE: To investigate the association between the timing of enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and smoking among prenatal WIC participants. METHODS: We use WIC data from eight states participating in the Pregnancy Nutrition Surveillance System (PNSS). We adjust the association between the timing of WIC participation and smoking behavior with a rich set of maternal characteristics. RESULTS: Women who enroll in WIC in the first trimester of pregnancy are 2.7% points more likely to be smoking at intake than women who enroll in the third trimester. Among participants who smoked before pregnancy and at prenatal WIC enrollment, those who enrolled in the first trimester are 4.5% points more likely to quit smoking 3 months before delivery and 3.4% points more likely to quit by postpartum registration, compared with women who do not enroll in WIC until the third trimester. However, among pregravid smokers who report quitting by the first prenatal WIC visit, first-trimester enrollment is associated with a 2% point increase in relapse by postpartum registration. These results differ by race/ethnicity; white women who enroll early are 3.6% points more likely to relapse, while black women are 2.5% points less likely to relapse. CONCLUSIONS: Early WIC enrollment is associated with higher quit rates, although changes are modest when compared to the results from smoking cessation interventions for pregnant women. Given the prevalence of prenatal smoking among WIC participants, efforts to intensify WIC's role in smoking cessation through more frequent, and more focused counseling should be encouraged.