Calcium Supplements Reduce Risk of Preeclampsia, Preterm Delivery

Pregnant women whose diets are low in calcium should take calcium supplements to reduce the risks of preeclampsia and preterm birth, a review of 13 studies concluded.

Pertinent Points

- Calcium supplements given to women on low calcium diets can reduce the risk of preeclampsia and premature birth.

- The daily dose of calcium supplementation should be at least 1 gram for the benefit of reducing preeclampsia and preterm births.

- However, lower doses of daily calcium may also have a benefit.

The meta-analysis, conducted by the Cochrane Pregnancy and Childbirth Group, found strong evidence that women taking high doses of at least 1 g/d of calcium throughout pregnancy reduced the average risk of high blood pressure (RR, 0.65), significantly reduced the risk of preeclampsia (RR, 0.45), and were less likely to deliver prematurely (RR, 0.76).

In addition, there was no evidence of adverse effects from taking the daily supplement.

“We considered these benefits to outweigh the increased risk of HELLP syndrome, which was small in absolute numbers,” the editors of the review noted, referring to hemolysis, elevated liver enzymes, and low platelets syndrome.

The review also showed that the risk of high blood pressure in women was reduced with calcium supplementation when compared with placebo.

Women who took calcium supplements were also less likely to die, with four trials showing a reduced composite outcome of maternal death or serious morbidity.

Limited evidence showed that when lower daily doses of calcium (500 to 600 mg/day) were taken, there was a potential for benefit, especially when compared with taking no supplementation. The evidence on lower dose usage was harder to evaluate because in many of those trials, calcium supplements were given in combination with other interventions, such as vitamin D, linoleic acid, or antioxidants.

While benefits were noted for both mother and baby, calcium supplementation did not reduce neonatal high-care admission or have an effect on stillbirth or infant death.