Serum Calcium and Magnesium Levels in Women Presenting with Pre-eclampsia: A Systematic Review and Meta-analysis Based on Observational Studies.

BACKGROUND

Multiple studies have investigated the serum concentrations of calcium (Ca) and magnesium (Mg) in preeclampsia, but the results have been contradictory. The objective of this systematic review and meta-analysis was to examine the association between serum calcium and magnesium levels in patients with preeclampsia and those in the healthy pregnancies.

MATERIALS AND METHODS

A comprehensive search was conducted in various online databases, including PubMed/Medline, Scopus, Embase, Web of Sciences, and Cochrane library to identify relevant studies on Ca and Mg levels in preeclampsia up to July 2023. Inter-study heterogeneity across the included studies was assessed using the chi-square test and I2 statistic. Pooled effect size (ES) was calculated as weighted mean differences (WMDs) with corresponding 95% confidence intervals (CI).

RESULTS

A total of 76 articles (comprising 92 studies) were included, with a combined sample size of 10,482 participants (preeclampsia: n=3,991; controls: n=6,491). The random-effects model revealed significantly lower levels of calcium (WMD=-0.807 mg/dL, 95% CI: -0.983, -0.632, P0.01) and magnesium (WMD=-0.215, 95% CI: -0.338, -0.092, P0.01) in women with pre-eclampsia compared to the control group. However, the overall pooled WMD for calcium and magnesium levels did not significantly change when individual studies were excluded one by one.

CONCLUSION

This meta-analysis demonstrates that the circulating levels of calcium and magnesium in patients with preeclampsia are significantly lower than those in the control group.