Ratio of Serum Calcium to Magnesium Levels on Pregnancy with and without Preeclampsia

BACKGROUND: Preeclampsia increases maternal and perinatal mortality and is affected by calcium and magnesium levels. Reduced extracellular levels of calcium and magnesium constitute the pathogenesis of eclampsia. A reduction in the calcium-magnesium ratio may aid in the detection and prevention of preeclampsia. MATERIAL/METHODS: This was an analytical observational study with a cross-sectional design, including patients with and without preeclampsia (inpatient and outpatient). A total of 246 patients were included in this research; 138 patients had preeclampsia and 108 patients did not. All examinations of magnesium and calcium levels at the Hasan Sadikin Hospital Clinical Pathology laboratory were conducted using an ion selective electrode modified with methylthymol blue complexometric titration. RESULTS: Patients with preeclampsia had significantly higher average serum magnesium and calcium levels than did patients without preeclampsia (2.85 vs 2.09, P=0.0001; 4.45 vs 4.85, P=0.025, respectively). Patients with preeclampsia demonstrated significantly lower serum calcium-magnesium ratios than did patients without preeclampsia (1.98 vs 2.60, P=0.0001). Receiver operating characteristic curve analysis on the serum calcium-magnesium ratio showed an area under the curve of 68.0% (P=0.0001), with a cutoff value of 2.36 (sensitivity 64.8%, specificity 62.3%), indicating that patients with serum calcium-magnesium ratios of <2.36 were predicted to have a risk of preeclampsia. CONCLUSIONS: Patients with preeclampsia had significantly lower serum calcium-magnesium ratios than did patients without preeclampsia; therefore, a low calcium-magnesium ratio could be a risk factor for preeclampsia.