Background: It is unclear if state laws supporting breastfeeding are associated with exclusive breastfeeding (EBF) practice among low-income mothers participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The main objectives of our study were to assess the relationship between such laws and EBF among WIC-participating mothers and to assess whether this association varied by employment status. We also assessed how mother’s exposure to WIC breastfeeding consultation was associated with EBF. Methods: A cross-sectional study was conducted across seven WIC program locations (i.e., Georgia, Massachusetts, Nevada, Pennsylvania, Wisconsin, Wyoming, Chickasaw Nation) between July–August 2020. Data were collected using convenient sampling from each program location and surveys were administered electronically or on paper to WIC-participating mothers. We restricted our analysis to data from 1161 WIC-participating mothers with infants aged zero to five months old. Multivariable mixed models were used to estimate the relationship between our exposures of interest (i.e., number of laws supporting breastfeeding, employment-related breastfeeding laws, WIC breastfeeding consultation) and EBF, while controlling for potential confounders and accounting for clustering by program location. Effect modification by employment status was assessed on the additive and multiplicative scales. Results: Among WIC-participating mothers living in program locations with no employment-related breastfeeding laws, EBF was 26% less prevalent for employed mothers compared to unemployed mothers (adjusted prevalence ratios [aPR]: 0.74, 95% CI: 0.67,0.83). Among all mothers, a one-unit increase in laws supporting breastfeeding was not associated with EBF (aPR: 0.88, 95% CI: 0.71,1.10). However, among employed mothers, living in areas with more employment-related laws was associated with a higher prevalence of EBF (aPR: 1.43, 95% CI: 0.83, 2.44). Infants whose mothers received a WIC breastfeeding consultation had 33% higher prevalence of being exclusively breastfed compared to infants whose mothers did not receive a WIC breastfeeding consultation (aPR: 1.33, 95% CI: 1.05,1.70). Conclusions: Infants whose WIC-participating mothers were employed, were less likely to be exclusively breastfed, but our effect modification analyses showed that laws supporting breastfeeding at the workplace may promote EBF among employed women. EBF was more prevalent among mothers who received a WIC breastfeeding consultation compared to those who did not receive such a consultation.
- Effect modification
- Exclusive breastfeeding