Calcium Supplementation During Pregnancy for Preventing Hypertensive Disorders Is not Associated with Changes in Platelet Count, Urate, and Urinary Protein: a Randomized Control Trial

Abstract

Objective. To test the hypothesis that calcium supplementation inhibits the underlying pathological processes in women with preeclampsia. Methods. Seven hundred and eight nulliparous women were enrolled in a WHO randomized double-blind trial, who received 1.5 g of calcium or placebo from 20 weeks of pregnancy or earlier. Platelet count, serum urate, and urinary protein/creatinine ratio were measured at or near 35 gestational weeks. Results. No difference was detected in rates of abnormal platelet count (relative risk [RR] 1.18; 95% confidence interval [CI], 0.63 to 2.18), serum urate level (1.0; 0.64 to 1.57) or urine protein/creatinine ratio (1.01; 0.76 to 1.34). This was consistent with the main trial finding of no difference in the incidence of ‘dipstick’ proteinuria between women receiving calcium and those receiving placebo (8312 women; RR, 1.01; 95% CI, 0.88 to 1.15). Conclusions. An effect of calcium supplementation in the second half of pregnancy on the rate of abnormal laboratory measures associated with preeclampsia was not demonstrated.

Keywords:

• Calcium supplementation
• Pre-eclampsia
• Proteinuria