Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems.

Abstract

BACKGROUND:

Calcium supplementation may prevent high blood pressure through a number of mechanisms and may help to prevent preterm labour.

OBJECTIVES:

The objective of this review was to assess the effects of calcium supplementation during pregnancy on hypertensive disorders of pregnancy and related maternal and child adverse outcomes.

SEARCH STRATEGY:

We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register and we contacted study authors.

SELECTION CRITERIA:

Randomised trials comparing at least one gram daily of calcium during pregnancy compared to placebo.

DATA COLLECTION AND ANALYSIS:

Eligibility and trial quality were assessed. Data extraction was carried out independently by two reviewers.

MAIN RESULTS:

Nine studies were included, all of good quality. There was a modest reduction in high blood pressure with calcium supplementation (relative risk 0.80, 95% confidence interval 0.73 to 0.88). The effect was greatest for women at high risk of hypertension (relative risk 0.35, 95% confidence interval 0.21 to 0.57) and those with low baseline dietary calcium (relative risk 0.49, 95% confidence interval 0.38 to 0.62). There was also a modest reduction in the risk of pre-eclampsia with calcium supplementation (relative risk 0. 72, 95% confidence interval 0.60 to 0.86). The effect was greatest for women at high risk of hypertension (relative risk 0.22, 95% confidence interval 0.11 to 0.43) and those with low baseline calcium intake (relative risk 0.32, 95% confidence interval 0.21 to 0.49). There was no overall effect on the risk of preterm delivery, although there was a reduction in risk amongst women at high risk of hypertension (relative risk 0.42, 95% confidence interval 0.23 to 0. 78). There was no evidence of any effect of calcium supplementation on stillbirth or death before discharge from hospital.

REVIEWER'S CONCLUSIONS:

Calcium supplementation appears to be beneficial for women at high risk of gestational hypertension and in communities with low dietary calcium intake. Optimum dosage requires further investigation.

• Authors: A N Atallah, G J Hofmeyr, L Duley
• Journal: The Cochrane database of systematic reviews (Cochrane Database Syst Rev) Issue 2 Pg. CD001059 ( 2000) ISSN: 1469-493X [Electronic] England
• PMID: 10796232 (Publication Type: Journal Article, Review, Systematic Review)

Chemical References

• Calcium

Topics

• Calcium
• Dietary Supplements
• Female
• Humans
• Hypertension (prevention & control)
• Pre-Eclampsia (prevention & control)
• Pregnancy
• Pregnancy Complications, Cardiovascular (prevention & control)