Intraoperative Transvaginal Ultrasonographic Evaluation for Placenta Accreta Spectrum in Placenta Previa: A Retrospective Observational Study.

AIM: To assess the utility of intraoperative transvaginal ultrasonography (TVUS) in evaluating the duration of blood flow in cervical hypervascularity as a real time diagnostic marker for placenta accreta spectrum (PAS) in placenta previa.

METHODS

This single-center historical cohort study included patients with placenta previa with intraoperative TVUS. The primary outcome was blood flow persistence time, defined as the interval from fetal delivery to disappearance of low-velocity (≤ 2.0 cm/s) color Doppler signals in cervical hypervascularity. Two obstetricians independently reviewed surgical video recordings. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of flow persistence time for predicting PAS. The AUC was calculated to assess discrimination. Optimal cutoffs were based on sensitivity and specificity. Independent predictors of PAS were identified by multivariate regression.

RESULTS

PAS was diagnosed in 20 cases (38.5%). Flow persistence time was significantly longer in PAS cases (20.20 ± 14.31 min) than in non-PAS cases (5.69 ± 2.46 min). A cut-off of 7 min achieved 100% sensitivity and 72% specificity (AUC = 0.94), reliably excluding PAS when flow ceased within this period. A threshold of ≥ 14 min yielded 100% positive predictive value for PAS and 96% specificity for predicting hysterectomy. Flow duration remained an independent predictor in multivariable analysis (AUC = 0.95).

CONCLUSIONS

Intraoperative assessment of cervical hypervascularity blood flow duration using TVUS may serve as a supportive indicator when PAS is suspected. A flow duration of < 7 min may help rule out PAS, while ≥ 14 min may suggest its presence and guide safer intraoperative management.