Prediction of Preeclampsia in Twins Using First Trimester: cffDNA Fraction, PlGF, and MAP.

OBJECTIVES

To evaluate cell-free fetal DNA fraction (cffDNAF) as a first-trimester screening marker for preeclampsia necessitating delivery before 37 weeks' gestation in twin pregnancies alone and combined with other bio-markers.

METHODS

Women with two live fetuses were enrolled in the first trimester, and evaluated for cffDNAF as a first trimester preeclampsia marker alone, and with placental growth factor (PlGF), mean arterial pressure (MAP), and uterine artery pulsatility index (UtA-PI).

RESULTS

There were 20 affected women; the cffDNAF was 9.0% (IQR: 8.4%-10.3%) in the affected, compared to 14% (IQR: 11%-16%) in 163 unaffected cases (p < 0.001). The AUROC for cffDNAF was 0.73 (95% CI: 0.61-0.85, p < 0.001), PlGF had an AUROC of 0.71 (0.59-0.83, p = 0.001), MAP had AUROC of 0.61 (0.50-0.72, p = 0.053) whereas UtA-PI had AUROC of 0.54 (0.39-0.69, p > 0.05). Combining all three biomarkers yielded an AUROC of 0.89 (0.78-0.98), with a sensitivity of 81%, specificity of 90%, negative predictive value (NPV) of 97.5%, and positive predictive value (PPV) of 50.7 UtA-PI did not contribute to the AUROC.

CONCLUSION

In twin pregnancies low first trimester cffDNAF effectively screens for preeclampsia necessitating delivery before 37 weeks' gestation, which is augmented with PlGF and MAP.