Calcium supplementation during pregnancy for the prevention of pre-eclampsia
Hypertensive disorders* such as pre-eclampsia and eclampsia are among the main causes of maternal deaths and preterm births, especially in low-income countries. Preterm births are the leading cause of early neonatal deaths and infant mortality, and survivors are at higher risk of respiratory disease and long-term neurological morbidity.
Normally, during early pregnancy, blood pressure falls and then slowly rises until the end of pregnancy. However, obesity, diabetes, twin or teenage pregnancies and low calcium consumption alter this equilibrium and increase the risk of developing pre-eclampsia. Calcium supplementation improves calcium intake and consequently reduces the risk of hypertensive disorders during pregnancy.
*disorders in which blood pressure is elevated
In populations where calcium intake is low, calcium supplementation as part of the antenatal care is recommended for the prevention of pre-eclampsia in pregnant women, particularly among those at higher risk of developing hypertension.
Additional information, including a suggested scheme for supplementation, can be found in the guidance summary, and in the guidelines under 'WHO documents' below.
Systematic reviews used to develop the guidelines
- Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems
- Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes