Short-term preeclampsia prediction: cutoff variations for sFlt-1/PlGF in U.S. Patients with or without hypertensive...

Preeclampsia (PE) is a complex disorder with significant maternal and fetal risks. The soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) ratio shows promise as a diagnostic tool, but its adoption in the U.S. remains limited due to the lack of accessible testing platforms, U.S.-based studies, and evidence-based implementation guidelines.

We conducted a cohort study to evaluate the sFlt-1/PlGF ratio for predicting PE within two weeks among pregnant individuals ≥18 years, ≥20 weeks gestation. Serum samples were obtained from routine prenatal visits or triage evaluations. sFlt-1/PlGF ratios were measured using Roche Elecsys assays, and performance was assessed by receiver operating characteristics (ROC) curve analysis with logistic regression, bootstrapping, and cross-validation.

The sFlt-1/PlGF ratio was higher in hypertensive (n = 119) than non-hypertensive patients (n = 346) (p < 0.001). PE developed in 9.7% of all patients and 37.0% of hypertensive patients within two weeks. ROC analysis showed an area under the curve (AUC) of 0.92 for the overall population, higher than 0.82 in the hypertensive group. The optimal cutoff for the overall population was 33, yielding a sensitivity of 93.8%, specificity of 81.3%, negative predictive value (NPV) of 99.2%, and positive predictive value (PPV) of 35.3%. For the hypertensive group, the optimal cutoff was 50, with a sensitivity of 81.7%, specificity of 73.1%, NPV of 87.6%, and PPV of 65.2%.

Performance differed between the overall and hypertensive populations, supporting the need for population-specific thresholds and further guidance for clinical implementation in the U.S.