First Trimester Screening of High-Risk Cases for Placenta Accreta by Using Transvaginal Scan and Serum PAPP-A: A Preliminary Study

Background: Placenta accreta spectrum (PAS) presents substantial risks to maternal and fetal well-being, emphasizing the need for early detection and intervention strategies. Objective: This study aimed to evaluate the efficacy of first-trimester ultrasound screenings and pregnancy-associated plasma protein A (PAPP-A) testing in detecting PAS.
Methods: This prospective study analyzed data of 88 patients who underwent first-trimester ultrasound screening and PAPP-A testing to evaluate the accuracy of early diagnostic methods for placenta accreta spectrum (PAS).
Results: 88 patients with mean age of 30.75 years and BMI of 26.92 kg/m² were included in this study. 38.6% had ≥ 3 prior CS. Patients with placenta accreta (n=13) had significantly higher BMI (32.7 vs. 26.0, p<0.001) and prior CS (3.2 vs. 2.3, p<0.001). First-trimester ultrasound had 92.3% sensitivity and 98% NPV, while PAPP-A alone was of weak predictive value (AUC = 0.546, p=0.597).
Conclusion: First-trimester PAPP-A was not a good predictor for diagnosing placenta accreta spectrum (PAS) but may have added value. Transvaginal ultrasound remains the preferred modality and is more reliable for screening early, particularly in high-risk populations. Combined marker strategies need to be developed to improve early detection and maternal outcomes.