Evaluation of urinary biomarkers in relation to the serum sFlt-1/PlGF ratio in pregnant women with suspected placental dysfunction.

INTRODUCTION

Urinary biomarkers may provide a non-invasive approach for assessing placental dysfunction. We evaluated their relationship with the clinically validated serum sFlt-1/PlGF ratio and clinically relevant pregnancy outcomes in women with suspected preeclampsia (PE) or fetal growth restriction (FGR).

MATERIALS AND

METHODS

This cross-sectional study included 151 pregnant women with suspected PE or FGR. Urinary placental growth factor (PlGF), myeloperoxidase (MPO), Serpin A7 (SA7), vascular endothelial growth factor A (VEGF-A), placental protein 13 (PP13) and endothelin-1 (ET-1) were evaluated according to a serum sFlt-1/PlGF ratio threshold of 38. ROC analyses assessed discriminatory performance overall and by gestational age at sampling (<34 and ≥ 34 weeks). Urinary PlGF was additionally evaluated against clinical outcomes and compared with the serum ratio for PE.

RESULTS

Urinary PlGF concentrations were lower in women with a serum sFlt-1/PlGF ratio > 38 (17.15 vs 32.13 pg/mL, p < 0.001) and showed the highest discriminatory performance among urinary biomarkers (AUC 0.73; 95%CI: 0.64-0.82), increasing to 0.85 (95%CI, 0.74-0.97) before 34 weeks. Urinary PlGF correlated negatively with the serum ratio before 34 weeks in women with a ratio ≤ 38 (rho = -0.77, p < 0.001). Urinary PlGF showed modest discrimination for PE (AUC 0.67) and FGR (AUC 0.64). For PE, the serum ratio outperformed urinary PlGF overall (AUC 0.82 vs 0.67; p = 0.001), whereas their AUCs did not differ significantly before 34 weeks (0.88 vs 0.80, p = 0.175).

CONCLUSIONS

Urinary PlGF may provide a feasible non-invasive biomarker of placental angiogenic imbalance, particularly before 34 weeks. It could complement serum-based assessment, although validation in larger independent cohorts is required.