Background: Preeclampsia is a hypertensive disorder of pregnancy that significantly contributes to maternal and perinatal morbidity and mortality, particularly in developing countries. Altered calcium metabolism has been suggested as a potential factor in the pathophysiology of preeclampsia, but findings remain inconsistent across populations.

Objectives: To estimate serum calcium levels among pregnant women diagnosed with preeclampsia and to assess the association between serum calcium levels and the severity of the condition.

Methods: A hospital-based cross-sectional study was conducted over 12 months at the Department of Obstetrics and Gynecology, Rajkiya Mahila Chikitsalaya, JLN Medical College, Ajmer. A total of 300 pregnant women with gestational age >28 weeks and clinically diagnosed preeclampsia were enrolled. Sociodemographic and obstetric data were collected using a pre-tested questionnaire. Serum calcium levels were measured using an enzymatic colorimetric method. Preeclampsia was classified as mild, moderate, or severe based on clinical criteria. Statistical analysis was performed using SPSS version 20.0, and a p-value <0.05 was considered statistically significant.

Results: The mean serum calcium level among participants was 9.56 ± 1.10 mg/dL. A significant inverse relationship was observed between serum calcium levels and the severity of preeclampsia. Women with mild preeclampsia had the highest mean calcium levels (9.58 ± 0.68 mg/dL), followed by those with moderate (8.67 ± 1.43 mg/dL), and severe preeclampsia (8.12 ± 1.54 mg/dL) (p < 0.0001). Additionally, the majority of participants belonged to rural areas and lower socioeconomic classes, with a high prevalence of overweight and obesity.