Biomarkers for Risk Stratification of Severe Maternal–Fetal Outcomes in Hypertensive Disorders of Pregnancy: A Retrospective Study

Background: Hypertensive disorders of pregnancy are associated with heterogeneous maternal and fetal risks, making early identification of patients at risk of severe adverse outcomes clinically important. Serum creatinine, uric acid, and D-dimer have uncertain incremental prognostic value among women with diagnosed hypertensive disorders of pregnancy. Methods: This single-center retrospective cohort study included women with hypertensive disorders of pregnancy who delivered during a predefined 4-year period. The earliest serum creatinine, uric acid, and D-dimer measurements obtained within 24 h of admission were analyzed. The primary outcome was a severe composite maternal–fetal outcome comprising predefined maternal, fetal, or neonatal events. Multivariable logistic regression assessed biomarker–outcome associations. Incremental predictive performance was evaluated using area under the receiver operating characteristic curve (AUC), calibration, Brier score, and decision curve analysis. A biomarker burden score and nomogram-based risk stratification were also assessed. Results: Among 612 patients screened, 428 were included, of whom 86 (20.1%) experienced severe composite outcomes. Serum creatinine, uric acid, and D-dimer were significantly higher in affected patients (all p < 0.001). Per 1-SD increase, adjusted odds ratios were 1.46 (95% CI, 1.12–1.91), 1.58 (1.21–2.08), and 1.42 (1.09–1.86), respectively. Outcome rates increased from 7.5% with no elevated biomarkers to 53.6% with all three elevated (p for trend < 0.001). With biomarker addition, AUC increased from 0.732 to 0.811 within the cohort (ΔAUC = 0.079; p < 0.001), alongside a lower Brier score and greater estimated net benefit. Observed event rates were 3.9%, 18.7%, and 60.2% in low-, intermediate-, and high-risk groups, respectively. Conclusions: These admission biomarkers showed incremental discrimination in this cohort but should complement, not replace, guideline-based assessment and require external validation.