Calcium Supplementation For The Prevention Of Pregnancy Induced Hypertension/Preeclampsia

Abstract

Background: Pregnancy induced hypertension (PIH) and preeclampsia (PE) contribute significantly to maternal and perinatal morbidity and mortality. The role of calcium supplementation towards preventing PIH/PE however remains unclear.
Objective: To assess the efficacy of calcium supplementation in prevention of PIH and PE. 
Materials and methods: An open label, randomized controlled trial conducted at the antenatal clinic of University of Abuja Teaching Hospital between July 2014 and June 2015. A total of 484 nulliparous women 16 weeks or less gestation and with normal blood
pressures were randomly assigned to either receive 1200mg of calcium tablet daily (N=242) or not to receive calcium tablets (N=242) from 16weeks until delivery. Primary outcome measure was development of PIH or PE and secondary outcome measure was preterm birth.
Results: The incidence of PIH was 7.7% among the intervention group compared to 13.7% in the control, p=0.039 and calcium supplementation reduced the risk of PIH (RR=0.56 (95% CI: 0.32-0.98)), but not PE. It also prolonged the duration of pregnancy in women who developed PIH (p=0.02). Incidence of preeclampsia was not significant, RR-0.56 (95% CI: 0.21-1.52) so also was the incidence of preterm delivery between the two groups (RR-0.65 (95% CI: 0.32-1.31)). No serious maternal side effects of treatment were recorded.
Conclusion: Calcium supplementation during pregnancy reduced the risk of PIH and thus may have a role in the prevention of PIH amongst nulliparous women. Its role in the absolute prevention of PE was not demonstrated in this study.