Independent factors associated with renal impairment in preeclampsia and its association with maternal and neonatal adverse outcomes.

Background: Renal impairment is a clinically important manifestation of preeclampsia and may identify patients at increased risk of adverse maternal and neonatal outcomes. This study evaluated independent factors associated with renal impairment in preeclampsia and examined the association between renal impairment and in-hospital maternal and neonatal adverse outcomes. Methods: This retrospective cohort study included 333 women with preeclampsia (PE) managed between June 2021 and June 2025. Patients were classified into renal-impairment and control groups. Baseline characteristics, laboratory variables, treatment exposure, and in-hospital outcomes were compared using appropriate parametric, nonparametric, or categorical tests. Univariable and multivariable logistic regression analyses were performed to identify factors associated with renal impairment and to evaluate its association with adverse outcomes. Model calibration, discrimination, and multicollinearity were assessed using the Hosmer-Lemeshow test, receiver operating characteristic curve analysis, and variance inflation factors, respectively. Sensitivity and subgroup analyses were performed according to alternative renal-impairment definitions and PE onset type. Results: In the primary multivariable model, higher body mass index (BMI), mean arterial pressure (MAP), and uric acid were independently associated with renal impairment, whereas later gestational age, higher albumin, and higher platelet count were inversely associated. In the expanded model, early-onset PE (adjusted odds ratio [aOR] 1.68, 95% confidence interval [CI] 1.02-2.78), MAP (aOR 1.73, 95% CI 1.26-2.37), 24-h urinary protein (aOR 1.58, 95% CI 1.25-2.00), serum uric acid-to-creatinine ratio (aOR 0.36, 95% CI 0.26-0.51), and albumin (aOR 0.87, 95% CI 0.81-0.94) remained associated with renal impairment. Renal impairment was independently associated with composite adverse maternal outcome (aOR 2.08, 95% CI 1.20-3.59), intensive care unit admission (aOR 3.39, 95% CI 1.65-6.95), eclampsia (aOR 3.92, 95% CI 1.09-14.14), preterm birth, low birth weight, low 5-min Apgar score, and neonatal intensive care unit admission. Conclusion: In preeclampsia, renal impairment was independently associated with hemodynamic severity, biochemical markers, and increased odds of major maternal and neonatal adverse outcomes. These findings suggest that renal impairment might serve as a clinically relevant marker for in-hospital risk stratification, although prospective validation is needed.