Urine and serum L-type fatty acid-binding protein levels in preeclampsia: a prospective cohort study on maternal deterioration prediction

We aimed to examine the association between maternal urine and serum L-type fatty acid-binding protein (L-FABP) levels and preeclampsia (PE) severity and their potential as predictors of maternal and fetal deterioration following PE diagnosis. A prospective cohort of women with singleton pregnancies diagnosed with PE was analyzed. Participants were classified into two groups based on the timing of delivery: PE-delivery (delivery within 1 week of sample collection) and PE-non-delivery (no delivery within 1 week). Urine and serum samples were collected at the time of PE diagnosis, and cases were classified based on the presence of maternal or fetal complications. In total, 53 singleton pregnancies were analyzed and classified into the PE-delivery (n = 32) and PE-non-delivery groups (n = 21). No significant differences in L-FABP levels were observed between severe and non-severe PE cases. However, L-FABP levels were significantly higher in cases of severe PE due to maternal factors. In the PE-delivery group, urine and serum L-FABP levels were significantly elevated in cases requiring delivery within 1 week due to maternal indications compared to the PE-non-delivery group, whereas no such differences were found in cases with fetal indications. Receiver operating characteristic analysis showed strong predictive performance of L-FABP levels for delivery within 1 week due to maternal deterioration, with areas under the curve of 0.892 (urine, cutoff: 12.3 μg/gCr) and 0.795 (serum, cutoff: 1.64 ng/mL). Maternal urine and serum L-FABP levels are closely associated with PE severity due to maternal complications and may serve as reliable biomarkers for imminent maternal deterioration.