Calcium supplementation to prevent pre-eclampsia--a systematic review.

Area of Science:

• Obstetrics and Gynecology
• Nutritional Science
• Public Health

Background:

• Hypertensive disorders of pregnancy are significant maternal health concerns.
• Preterm labor remains a leading cause of perinatal morbidity and mortality.
• Calcium intake during pregnancy is a modifiable factor with potential health implications.

Purpose of the Study:

• To evaluate the efficacy of calcium supplementation in preventing hypertensive disorders of pregnancy.
• To assess the impact of calcium on maternal and infant adverse outcomes.
• To synthesize evidence from randomized controlled trials on calcium supplementation in pregnancy.

Main Methods:

• Systematic review of randomized controlled trials (RCTs).
• Inclusion criteria: at least 1 g daily calcium supplementation versus placebo during pregnancy.
• Data extraction and quality assessment of eligible trials.

Main Results:

• Calcium supplementation showed a modest reduction in pre-eclampsia risk (RR 0.68).
• Significant benefits observed in high-risk hypertensive women and those with low baseline calcium intake.
• Reduced incidence of low birth weight (<2,500g) babies (RR 0.83).
• No overall effect on preterm delivery, but reduced risk in high-risk hypertensive women.
• No impact on stillbirth or early mortality.
• Potential reduction in childhood high systolic blood pressure noted in one study.

Conclusions:

• Calcium supplementation may benefit pregnant women at high risk of gestational hypertension or with low dietary calcium intake.
• Observed benefits were primarily in smaller trials and not replicated in a large, low-risk population study.
• Further research is warranted to clarify the role and optimal use of calcium supplementation in pregnancy.