Background: Previous research has noted an association between breastfeeding and a reduced risk of postpartum depression (PPD). This article provides a systematic review and meta-analysis on the possible association of the type and degree of breastfeeding and PPD. Methods: A systematic literature search in English was conducted by using PubMed, Google Scholar, Scopus, Web of Science, and Cochrane Library Databases from their start dates until January 2021. Outcome estimates were pooled by odds ratios (ORs) or standardized mean differences. Result: Women who did not exclusively breastfeed had 89% higher odds of PPD (OR = 1.89, 95% confidence interval [CI]: 1.50-2.39). Included studies used different cutoff points for the diagnosis of PPD. Therefore, PPD in nonexclusive breastfeeding mothers was more in studies using the cutoff point 9/10 (OR 1.97, 95% CI 1.46-2.64) as symptoms of depression than those using the cutoff point 12 (OR 1.78, 95% CI 1.21-2.61). Some studies reported PPD based on means and the others reported it based on OR. Accordingly, nonexclusive breastfeeding mothers had higher odds of PPD in studies calculating the effect size based on means (OR 1.62, 95% CI 1.19-2.19) and OR (OR 2.36, 95% CI 1.65-3.39) than in other studies. Conclusion: This review showed that exclusive breastfeeding is associated with a reduced risk for PPD.
Keywords: breastfeeding; exclusive breastfeeding; postnatal depression; postpartum depression.