The effect of immediate postpartum depot medroxyprogesterone on early breastfeeding cessation

Background: This study evaluated the effect of immediate postpartum depot medroxyprogesterone (DMPA) on breastfeeding cessation within 6 weeks postpartum. Study Design: At low-income-serving obstetric and pediatric clinics, eligible mothers within 1 year postpartum were recruited to participate in a retrospective cohort study. The 183 participants completed a self-administered survey. Surveys were merged with birth certificate data and perinatal maternal/infant medical records. Kaplan-Meier distributions assessed the relationship between DMPA use and breastfeeding cessation. A multivariable Cox proportional hazards model estimated hazard ratios (HRs) and included five known risk factors (age, education, race, parity and parental cohabitation) and identified potential confounders. Results: Consistent with the biologic model, the Kaplan-Meier results raised the possibility of a detrimental effect of DMPA on duration of any breastfeeding, but differences in these distributions did not achieve statistical significance (p=.24); after adjustment for potential confounders, this nonstatistically significant association remained (HR: 1.22; confidence interval: 0.75-1.98). Conclusion: Given the state of the evidence, it is unclear whether a causal effect does or does not exist. However, if there is a causal effect of DMPA on breastfeeding duration, it is minimal. Additional well-designed research is warranted.