Does the Addition of Serum PAPP-A and β-hCG Improve the Predictive Value of Uterine Artery Pulsatility Index for Preeclampsia at 11-14 Weeks of Gestation? A Prospective Observational Study.

Objective: To study the role of uterine artery Doppler pulsatility index (UtA-PI), serum pregnancy-associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotropin (fβ-hCG) levels, individually and in combination with each other, at 11-14 weeks of gestation for prediction of preeclampsia (PE).

Methods: In a prospective observational study, a total of 100 low-risk gravid females were recruited at 11-14-weeks of gestation. UtA-PI, PAPP-A and fβ-hCG levels were estimated. These women were followed up until delivery for the development of PE and gestational hypertension (GH).

Results: The best individual marker for screening PE and GH was UtA-PI with ROC AUC (± standard error) = 0.934 ± 0.028, p < 0.0001. UtA-PI at a cutoff value of ≥ 2.8 (95th percentile) had 77.8% sensitivity, 98.9% specificity, 97.8% NPV and 87.5% PPV in detecting PE. PAPP-A (MoM) at a cutoff value of ≤ 0.27 (5th percentile) demonstrated 44.4% sensitivity, 95.6% specificity, 94.5% NPV and 50% PPV. fβ-hCG (MoM) at a cutoff value of ≤ 0.5 (5th percentile) had a specificity of 94.5%. Among the combined markers, UtA-PI along with PAPP-A estimation served best with a sensitivity and specificity of 44% and 100%, respectively. Addition of fβ-hCG to either UtA-PI or PAPP-A levels was not found sensitive for detecting PE but yielded 100% specificity and 96% NPV.

Conclusions: UtA-PI as a stand-alone test was found most useful for the prediction of PE. Addition of either or both of PAPP-A and fβ-hCG to UtA-PI did not improve the sensitivity of combined test with only a slight improvement in specificity and NPV. Their routine addition to UtA-PI studies is not recommended for prediction of PE at 11-14 weeks of gestation in low- and lower-middle-income countries (LMIC).