Serum osteoprotegerin levels and their association with preeclampsia severity: a case-control study

Preeclampsia is a hypertensive disorder of pregnancy associated with significant maternal and neonatal morbidity and mortality. Osteoprotegerin (OPG), a glycoprotein involved in vascular homeostasis, has emerged as a potential biomarker for disease severity. This study aimed to evaluate serum OPG levels in pregnant women with and without late-onset preeclampsia and to assess its correlation with disease severity and clinical outcomes. This case–control study was conducted at Ain Shams University Maternity Hospital between August 2022 and January 2024. Ninety pregnant women with gestational age ≥ 34 weeks were enrolled and equally divided into three groups: normotensive controls (n = 30), mild late-onset preeclampsia (n = 30), and severe late-onset preeclampsia (n = 30). Clinical assessments, laboratory investigations, and serum OPG levels (measured by ELISA) were compared among groups. Correlation, multivariate regression, and receiver operating characteristic (ROC) curve analyses were performed. Serum OPG levels were significantly higher in women with late-onset preeclampsia, particularly in the severe group (p < 0.0001). Elevated OPG levels were strongly correlated with adverse perinatal outcomes, including fetal growth restriction, preterm delivery, NICU admission, and cesarean delivery. Multivariate regression analysis demonstrated that OPG levels were independently associated with preeclampsia severity and adverse perinatal outcomes. ROC analysis showed excellent diagnostic performance of OPG in identifying severe late-onset preeclampsia (AUC = 0.976), with sensitivity and specificity of 93.3%. Serum OPG levels are significantly elevated in late-onset preeclampsia and correlate closely with disease severity and adverse maternal and fetal outcomes. OPG shows promise as a clinical biomarker for identifying severe late-onset preeclampsia, although its utility in mild disease appears limited.