Association of Neutrophil Gelatinase‐Associated Lipocalin ( NGAL ) Levels With Acute Kidney Injury and Postpartum Renal Functional Recovery in Patients With Preeclampsia

ABSTRACT Objective To examine the association between neutrophil gelatinase‐associated lipocalin (NGAL) level and acute kidney injury as well as postpartum renal functional recovery. Methods A retrospective study was conducted on 100 preeclampsia patients who were admitted and delivered in the Department of Obstetrics at our hospital between July 2024 and January 2025. Among them, 26 patients had concurrent acute kidney injury (AKI) while 74 did not. Demographic data and laboratory parameters were collected for all patients. Statistical analyses included Student's t ‐test, Pearson correlation analysis, and receiver operating characteristic (ROC) curve analysis for comparisons. Results Compared with the non‐AKI group, the AKI group exhibited significantly higher levels of 24‐h urinary protein excretion (1.91 ± 0.68 vs. 0.74 ± 0.20 g/24 h, p < 0.001), D‐dimer (5.15 ± 0.73 vs. 3.15 ± 1.13 mg/L, p < 0.001), and neutrophil gelatinase‐associated lipocalin (NGAL; 461.33 ± 75.74 vs. 370.22 ± 56.51 ng/mL, p < 0.001), but a significantly lower estimated glomerular filtration rate (eGFR; 165.27 ± 19.44 vs. 181.66 ± 25.80 mL/min/1.73m 2 , p = 0.004). NGAL level showed positive correlations with D‐dimer ( r = 0.402) and 24‐h urinary protein excretion ( r = 0.367). The area under the curve (AUC) for predicting AKI occurrence superimposed on preeclampsia (PE) was 0.974 for 24‐h urinary protein excretion,0.699 for eGFR,0.923 for D‐dimer and 0.841 for NGAL, indicating their predictive value. Compared with Day 1, NGAL levels decreased on Days 5 and 7 in the renal function recovery group, while NGAL levels increased on Day 7 in the group without renal function recovery. Conclusion Elevated serum NGAL levels at admission are significantly associated with acute kidney injury in patients with preeclampsia and serve as a valuable predictor for its occurrence, as evidenced by a high AUC.