Palacios C.; Pena-Rosas JP
Hypertension complicates approximately 10% of all pregnancies worldwide, and pre-eclampsia and eclampsia are major causes of maternal and perinatal morbidity and mortality (1). Currently, preeclampsia and gestational hypertension are considered either separate diseases affecting the same organs or different levels of severity of the same underlying disorder (2). Based on available estimates and case–fatality rates, each year up to 40 000 women, mostly in developing countries, die of hypertensive disorders (3). Pre-eclampsia and eclampsia complicate 2–8% of pregnancies and, overall, 10–15% of direct maternal deaths are associated with these conditions (1).
A recent systematic review which sought to determine the distribution of causes of maternal deaths found a wide regional variation (4). Hypertensive disorders were reported as the cause of 16.1% of maternal deaths in developed countries, 9.1% in Africa, 9.1% in Asia, and 25.7% in Latin America and the Caribbean (4).
Observational studies have found an inverse association between maternal calcium intake and hypertension disorders of pregnancy (5). Clinical trials have also confirmed that calcium supplementation reduces blood pressure and hypertension-related disorders (6). However, the effects of this intervention on other maternal outcomes and on the mothers’ offspring is less clear. The present RHL commentary relates to the review by Hofmeyr et al (7), which assessed the effects of supplementation with 1 g or more of calcium per day on hypertensive disorders and other maternal and child outcomes in non-hypertensive pregnant women at less than 34 weeks of gestation.