Circulating neutrophil gelatinase-associated lipocalin and preeclampsia: a meta-analysis.

BACKGROUND: Previous studies evaluating the association between circulating neutrophil gelatinase-associated lipocalin (NGAL) and the risk of preeclampsia (PE) showed inconsistent results. A systematic review and meta-analysis was performed to summarize the relationship between circulating NGAL and PE. METHODS: Studies comparing the circulating NGAL between pregnant women with PE and controls with no PE were found by searching Medline, Web of Science, Cochrane's Library, and Embase. Pooling results was performed using a random-effects model incorporating heterogeneity. RESULTS: In the study, 1293 women with PE and 1773 healthy pregnant women were enrolled in 18 case-control studies, and the gestational age was matched between cases and controls. Pooled results showed that compared to controls, women with PE had a significantly higher blood level of NGAL (standardized mean difference [SMD]: 0.95, 95% confidence interval [CI]: 0.63-1.28, p < .001; I2 = 92%). Subgroup analyses showed consistent results in studies of NGAL measured at the first (SMD: 0.47, 95% CI: 0.15-0.80, p = .004), the second (SMD: 0.87, 95% CI: 0.55-1.19, p < .001), and the third trimester (SMD: 1.06, 95% CI: 0.63-1.24, p < .001) of pregnancy. In addition, women with mild (SMD: 0.78, 95% CI: 0.13-1.44, p = .02) and severe PE (SMD: 1.19, 95% CI: 0.40-1.97, p = .003) both had higher circulating NGAL as compared to controls. CONCLUSIONS: High circulating NGAL is associated with PE, which may be independent of the trimesters for blood sampling and the severity of PE.