Breastfeeding and maternal health outcomes: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to evaluate the impact of breastfeeding duration and type on various long-term and short-term maternal health outcomes. Specifically, the researchers investigated breast carcinoma, ovarian carcinoma, osteoporosis, type 2 diabetes mellitus, lactational amenorrhoea, postpartum depression, and postpartum weight change.

The authors conducted a comprehensive search of PubMed, the Cochrane Library, and CABI databases through February 2015. They identified 163 eligible studies, including observational cohorts and case-control studies. The team performed new meta-analyses for breast and ovarian cancer, osteoporosis, and lactational amenorrhoea, while updating existing reviews for type 2 diabetes, postpartum depression, and weight change. They utilized random-effects models and subgroup analyses to address heterogeneity and assess the impact of study quality and confounding factors like parity.

The study found clear evidence that longer durations of breastfeeding are protective against several chronic conditions. Breastfeeding for more than 12 months was associated with a 26% reduction in breast cancer risk and a 37% reduction in ovarian cancer risk. Additionally, breastfeeding was linked to a 32% lower risk of developing type 2 diabetes. Regarding short-term outcomes, exclusive and predominant breastfeeding were significantly associated with an increased duration of lactational amenorrhoea. However, the researchers found no conclusive evidence linking breastfeeding to changes in bone mineral density, postpartum depression, or postpartum weight loss.

These findings reinforce the importance of breastfeeding not only for infant health but also as a significant preventive health measure for mothers. By quantifying the protective effects against major cancers and metabolic diseases, this review provides strong evidence to support public health policies that encourage and facilitate longer breastfeeding durations. The lack of evidence for other outcomes, such as weight loss, highlights the need for more rigorous, longitudinal research to better understand the full spectrum of maternal health impacts.