Association Between Duration of Breastfeeding and Maternal Hypertension: A Systematic Review and Meta-Analysis

Recently, an increasing number of studies have implied that breastfeeding has a protective effect on maternal hypertension, but it remains controversial. The aim of this study is to evaluate the effect of breastfeeding on maternal hypertension through meta-analysis. Eligible studies were searched and identified in various databases. Meta-analysis was conducted to assess the association between the duration of breastfeeding and maternal hypertension. Seven eligible studies that contained 444,759 participants were included in our study. Meta-analysis of these seven studies showed a significant protective effect of breastfeeding on maternal hypertension. Specifically, pooled odds ratios (ORs) of hypertension for >0-6, >6-12, and >12 months of breastfeeding were 0.92 (95% confidence interval [CI]: 0.88-0.96, I = 67.5%), 0.89 (95% CI: 0.86-0.92, I = 0), and 0.88 (95% CI: 0.84-0.93, I = 43.9%), respectively, compared with nonbreastfeeding mothers, and the pooled OR of hypertension was 0.93 (95% CI: 0.91-0.95, I = 40.8%) for women who breastfed compared with women who had not. Furthermore, the pooled hazard ratio of hypertension was 1.34 (95% CI: 1.17-1.52, I = 58.7%) for women who did not breastfeed compared with women who breastfed for more than 12 months for their first child. Different durations of breastfeeding have different protective effects against the development of maternal hypertension, and breastfeeding for >12 months has a better effect than