Serum tumor necrosis factor-α level and uterine artery Doppler indices at 11-13 weeks' gestation for preeclampsia screening in low-risk pregnancies: a prospective observational study

Preeclampsia affects 1-2% of human pregnancies with no effective screening test. Studies have found some association between cytokines/other biomarkers and the later onset of preeclampsia. The challenge has been to find indicators with sufficient positive predictive value. A prospective observational study recruiting 500 low-risk pregnant women was carried out. Serum TNF-α and uterine artery Doppler were measured at 11-13 weeks. TNF-α cut-off value ≥14 pg/mL had a sensitivity of 67.8% and a specificity of 98% in predicting PE with PPV of 79.4% and NPV of 96.4%. Mean uterine artery PI ≥1.7 had a 100% sensitivity and 84.4% specificity in predicting PE, with a PPV of 41.7% and NPV of 100%. When combining both parameters together we had 88.6% sensitivity and 100% specificity in predicting PE with a PPV of 100% and NPV of 98.6%. Serum TNF-α assay improves the performance of mean uterine artery PI at 11-13 weeks for PE screening and the combination of both tests can rule out PE in the case of normal results.