Marissa Nahirney, Amy Metcalfe, Katie H Chaput

Postpartum depression (PPD) is a common complication of pregnancy, affecting approximately 13% of mothers internationally. Previous research has examined whether epidural analgesia used for pain control during labor and birth is associated with a lower risk of PPD, but reports conflicting results and may have suffered from methodological shortcomings. Our study aimed to prospectively assess whether epidural analgesia is associated with a lower risk of PPD (at either 6 weeks or 6 months postpartum) after attempting to adequately adjust for selection bias and confounding variables. We conducted a secondary analysis of a prospective cohort of urban Canadian mothers who were recruited at birth in Calgary, Canada, in 2010, for a primary study on predictors of PPD. Mothers with full-term, singleton infants who did not require neonatal intensive care unit admission of >24 hours were included, and filled out questionnaires at birth, 6 weeks and 6 months postpartum including demographics, birth data, maternal and infant physical health, lifestyle, breastfeeding and maternal mental health. Descriptive statistics were calculated for participant characteristics and to identify potential confounder variables. Multivariable logistic regression analysis was conducted to assess whether epidural analgesia is associated with PPD after controlling for available confounding variables. Our study included 206 mothers who had vaginal deliveries and were free of depression at delivery. We found an incidence of PPD of 13.3% (n=27) and no statistically significant association between epidural use and PPD, regardless of adjustment for potential confounding variables (unadjusted odds ratio [OR] 0.86, 95% confidence interval [CI] 0.69-1.22; adjusted OR (for body mass index 1.04, 95% CI 0.40-2.77). We did not observe a significant association between epidural use and PPD. While the CIs are wide, we do not believe that this masks a clinically relevant association, and as such, the risks and benefits of epidural analgesia communicated to women during labor and delivery should not be modified.