A New Standard for Calcium Replacement in Pregnancy

Hypertension during pregnancy can be a life-threatening illness for both the mother and the baby. The most severe form of hypertension during pregnancy is preeclampsia, which is a leading cause of premature birth worldwide.

While delivery of the fetus will resolve preeclampsia, premature delivery of the fetus can result in a higher risk of infant mortality. Prevention of preeclampsia is therefore much preferred to treatment.

Calcium supplementation in areas of low dietary calcium intake has proven effective in reducing the risk of preeclampsia by 50%. Unfortunately, the WHO recommendation for 1500 to 2000 mg of daily calcium involves administration around the clock, which is cumbersome and has precluded the widespread use of this vital therapy.

In this installment of Talking Therapeutics, we explore a new study that evaluated a simplified calcium administration plan to prevent hypertensive-related pregnancy complications.

Talking Point: Simpler is Better

A new trial, which randomized 11,000 nulliparous pregnant women in India and Tanzania to a 500 mg daily dose or to a 1500 mg daily dose of calcium supplementation, proved that the old adage is true. The cumulative incidence of preeclampsia was 3.0% in the 500 mg group and 3.6% in the 1500 mg group in the India trial, and 3.0% and 2.7%, respectively, in the Tanzania trial. Noninferiority was established between both calcium regimens in both cohorts of women.

The percentage of live births that were preterm was 11.4% in the 500 mg group and 12.8% in the 1500 mg group in the India trial, which was within the noninferiority margin. However, in the Tanzania trial, the respective percentages were 10.4% and 9.7% (relative risk, 1.07; 95% CI, 0.95 to 1.21), which exceeded the noninferiority margin.

Talking Point: Setting a New Standard

We need to wait for the WHO to weigh in on this trial and determine if they will change their official recommendation, but the results of this study are highly encouraging. The lower-dose calcium regimen is much more practical for patients to take and will greatly lower the associated costs with calcium replacement. This should drastically increase the number of women who receive this life-changing therapy, which should override the potential for a slightly higher rate of preterm labor in that was seen in one arm of the low-dose calcium regimens.