(357) Correlation of Placenta Accreta Index to Surgical Outcomes for Pregnancies with Suspected Placenta Accreta Spectrum

The Placenta Accreta Index (PAI) is a validated tool combining clinical and sonographic findings to predict placenta accreta spectrum (PAS). While effective for prenatal diagnosis in high-risk populations, its correlation to surgical outcomes remains unclear. We evaluated whether higher PAI scores are associated with increased surgical morbidity.

Study Design:

Single center retrospective cohort of patients referred for suspected PAS who were evaluated and delivered at a large academic center between January 2023-July 2025. Inclusion required ≥ 1 prior cesarean and confirmed low-lying or previa placentation. Blinded investigators reviewed third-trimester ultrasounds to calculate PAI scores stratified into three groups: group 1 (PAI ≤3), group 2 (PAI >3 to ≤6), and group 3 (PAI >6). The primary outcome was a composite severe maternal morbidity (SMM) score. Secondary outcomes included FIGO grade, quantitative blood loss (QBL), and use of ureteral stent and aortic occlusion devices. Multivariate analyses and logistic regression were performed.

Results:

Ninety patients were included. SMM increased significantly across PAI groups (23.5% vs. 55.6% vs. 60.9%; p=0.029). Compared to group 1, the odds of SMM were 4.0x higher in group 2 (CI 1.1–15.7) and 5.1x in group 3 (CI 1.4–17.9). Increasing PAI scores were associated with less frequent low-transverse hysterotomy (p< 0.001), greater incidence of FIGO grade ≥ 3 (p< 0.001), higher QBL (p=0.038), longer operative times (p< 0.001), and increase perioperative placement of ureteral stents (p=0.007) and aortic occlusion devices (p=0.005 respectively).

Conclusion:

Increasing PAI scores are associated with increased risk of SMM. Increased scores also demonstrate increased FIGO pathologic grading, blood loss, operative times, and use of ureteral stents and aortic occlusion devices. These findings support the use of PAI not only for prenatal diagnosis of PAS but also as a tool for preoperative planning and management of surgical complexity and morbidity in patients with suspected PAS.