Longitudinal Assessment of Calcium and Magnesium Levels in Women with Preeclampsia

The present study reports the levels of maternal serum calcium and magnesium from early pregnancy until delivery, along with cord levels, in women who developed preeclampsia (PE) and compares them with those without PE. A total of 324 pregnant women (216 non-PE and 108 PE women) were included in this retrospective case–control study of prospectively collected data nested in an observational cohort study. Maternal blood was collected at 4 time points during pregnancy (V1 = 11–14 weeks, V2 = 18–22 weeks, V3 = 26–28 weeks, and V4 = at delivery) and umbilical cord blood at delivery. Independent t tests were used to compare calcium, magnesium, and their ratio between two groups, and their associations with PE were studied using regression models. Calcium levels were similar between groups at all time points. Magnesium levels were lower ( p = 0.021) at V2 in PE group as compared with non-PE group. Maternal calcium and magnesium levels were negatively associated, with blood pressure in early pregnancy. In fully adjusted logistic regression analysis, lower magnesium levels were associated with an increased risk of PE at V2 (OR 0.25 [95% CI 0.07, 0.94] p = 0.04). Lower magnesium in mid-pregnancy was associated with higher risk of PE. These changes were observed before the diagnosis of PE, thereby suggesting that they may have a role in the etiology of PE.