Maternal Dietary Patterns and Pregnancy Hypertension in Low- and Middle-Income Countries: A Systematic Review and Meta-analysis.

Healthy maternal diets can lower the odds of developing pre-eclampsia, a direct and second leading cause of maternal death, globally. However, there is a research gap in low- and middle-income countries (LMIC), which bear a disproportionate burden of these deaths. The objectives of this systematic review were to: 1) evaluate the association between dietary patterns in pregnancy and hypertensive disorders, including pre-eclampsia for pregnant and postpartum women in LMIC, and 2) compile barriers and facilitators to an adequate maternal diet. A systematic search was performed on MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health, Web of Science, Cochrane Central Register of Controlled Trials, African Journals Online, the WHO Regional Databases, 2 trial registries, Google Scholar, and reference lists. Included in the analysis were primary research studies of dietary patterns during pregnancy, with pregnancy hypertension outcome(s), and conducted in LMIC. Included studies were assessed using ROBINS-I risk of bias. Thirteen studies were included, of which 5 studies were included in a meta-analysis (Review Manager 5). Lower odds of pre-eclampsia were associated with adequate (compared with no or low) consumption of vegetables (OR: 0.38; 95% CI: 0.18, 0.80; I2 = 85%; P = 0.01) and adequate (compared with no or low) consumption of fruit (OR: 0.42; 95% CI: 0.24, 0.71; I2 = 79%; P = 0.008). No firm conclusions could be drawn about the impact on pre-eclampsia odds of any of the following during pregnancy: high consumption of meat or grains; a "Western" diet; or alcohol consumption. More LMIC-based research is needed to explore whether the apparent beneficial effects of fruits and vegetables on pre-eclampsia incidence might be enhanced when maternal malnutrition is prevalent, and/or whether other sociodemographic factors might contribute.