Endothelial Leakage-Erythrocyte Stress Index for the prediction of pre-eclampsia in the first trimester: A preliminary, hypothesis-generating retrospective case-control study.

Pre-eclampsia is a major cause of maternal and perinatal morbidity, and there remains a need for reliable and easily accessible biomarkers for early prediction. The Endothelial Leakage-Erythrocyte Stress (ELES) index is a novel composite biomarker derived from routine first-trimester red cell distribution width (RDW), aspartate aminotransferase (AST), and serum albumin, reflecting endothelial leakage and erythrocyte stress. This retrospective case-control study evaluated the predictive value of the ELES index for pre-eclampsia in singleton pregnancies undergoing routine laboratory assessment at 11-13 + 6 weeks who delivered at the same hospital. First-trimester ELES index values were significantly higher in women who later developed pre-eclampsia than in controls (6.36 ± 2.59 vs 4.75 ± 1.38, P < .001), with an AUC of 0.75 (95% CI: 0.65-0.85); at a cutoff of ≥5, sensitivity and specificity were 76.3% and 65.0%, respectively. After adjustment for maternal age and obstetric characteristics, ELES ≥ 5 remained independently associated with pre-eclampsia (OR 5.971, 95% CI: 2.427-14.688, P = .001); higher AST and lower albumin were also independently associated. Albumin alone yielded the highest AUC (0.775, 95% CI: 0.689-0.847), and the ELES index was not statistically superior to albumin alone (DeLong P = .698). Because first-trimester albumin is not part of routine national antenatal screening, only women in whom this measurement had already been requested could be analyzed, and BMI, aspirin prophylaxis, gestational age at diagnosis, and disease severity were not retrievable. These findings should therefore be regarded as preliminary and hypothesis-generating, requiring prospective validation in a broader obstetric population before clinical use.