Prenatal ultrasound markers for predicting blood transfusion in placenta accreta spectrum

Placenta accreta spectrum (PAS) is a leading cause of severe bleeding during childbirth and often requires complex surgery and blood transfusions. The aim of this study was to investigate whether prenatal ultrasound findings, particularly those reflecting vascular and cervical topography, can more accurately predict the need for transfusions.

Sixty-one surgically confirmed PAS cases from two tertiary centers were analyzed. The uterine spairing surgery and cesarean hysterectomy groups were compared in terms of antenatal ultrasonographic markers. Transfusion burden was first adjusted for preoperative hemoglobin level and cesarean hysterectomy status; then residual variability in the model was examined to assess the independent prognostic contribution of ultrasound markers.

The need for transfused erythrocyte suspension (RBC) was significantly higher in women undergoing cesarean hysterectomy compared to those undergoing uterine-sparing surgery (2.7 ± 1.7 vs. 1.4 ± 1.3 units, p = 0.003). After correction, uterovesical hypervascularity (β = 0.565, p = 0.034) and placental vessel extension to the cervix (β = 0.640, p = 0.011) remained independently associated with transfusion burden.

While classic findings such as loss of clear zone and placental lacunae support the diagnosis of PAS, vascular findings in the lower uterine segment and cervical region better reflect surgical difficulty and hemorrhagic burden. Focusing on these prognostic ultrasound markers can strengthen preoperative risk assessment, improve multidisciplinary surgical planning, and contribute to more reliable prediction of transfusion needs.