Evaluating transvaginal ultrasound in placenta accreta spectrum scoring to determine placenta accreta spectrum...

We previously developed the transvaginal ultrasound in placenta accreta spectrum scoring system to stratify severity of suspected placenta accreta spectrum cases. By evaluating the loss of uterine wall interface in the lower uterine segment, arterial vascularity, and cervical involvement, we established a framework to categorize placenta accreta spectrum severity based on its association with intraoperative blood loss.

This study evaluates the performance of transvaginal ultrasound in placenta accreta spectrum scoring in an independent cohort and assesses its association with blood loss and surgical complexity, such as cystotomy.

We studied a retrospective cohort of consecutive patients referred to a quaternary center for suspected placenta accreta spectrum from 2023 to 2024. The lower uterine segment and cervix were evaluated by transvaginal ultrasound per predefined protocol, evaluating the utero-placental interface and cervical involvement with bladder half-full. Patients were managed per usual clinical approach, not based on transvaginal ultrasound in placenta accreta spectrum scoring, including cesarean section with placenta removal, cesarean hysterectomy, and conservative management with or without delayed hysterectomy. An examiner blinded to patient history and clinical outcomes retrospectively scored images and clips. Patients were assigned scores of 0 to 3 in 3 domains: uterine wall defect, arterial vascularity, and cervical involvement. Cumulative scores of 0 to 9 were converted into 4 categories, as previously published: Category 0: placenta accreta spectrum score 0; Category 1: placenta accreta spectrum score 1 to 3; Category 2: placenta accreta spectrum score 4 to 6; and Category 3: placenta accreta spectrum score 7 to 9. The primary outcome was calculated estimated blood loss during the primary surgery. Secondary outcomes were blood product transfusion, intensive care unit admission, length of hospital stay, and bladder injury.

Of 86 patients referred, 78 were included in the analysis. Transvaginal ultrasound in placenta accreta spectrum scores were distributed as follows: 20 patients (25.6%) were classified as Category 0, 11 (14.1%) as Category 1, 25 (32%) as Category 2, and 22 (28.2%) as Category 3. The primary outcome, calculated estimated blood loss, differed significantly by transvaginal ultrasound in placenta accreta spectrum scoring category: median (interquartile range) calculated estimated blood loss was 738 (604-926) mL in Category 0, 1167 (949-1677) mL in Category 1, 1166 (732-1871) mL in Category 2, and 1353 (1028-2250) mL in Category 3 (P<.001). Category 3 was independently associated with greater blood loss than other categories (β=1.35, P=.002). Cystotomy was exclusively performed in Category 3 patients (27.2%). Additionally, Category 3 had the highest rate of intensive care unit admission (86.3%), with 5%, 18.1%, and 60% in Categories 0, 1, and 2, respectively (P<.001). Surgical management differed across transvaginal ultrasound in placenta accreta spectrum categories. Cesarean hysterectomy was more common in Categories 2 and 3 (40% each) than Categories 1 (18%) and 0 (0%) (P<.0001). Conservative management with or without delayed hysterectomy was most frequent in Category 3 (54.5%), at nearly twice the rate as in Category 2 (24%); no patients in Categories 0 and 1 underwent conservative management (P<.001). These trends suggest that higher transvaginal ultrasound in placenta accreta spectrum categories align with more extensive surgical interventions, although management remains multifactorial.

Our study evaluated transvaginal ultrasound in placenta accreta spectrum scoring in an independent cohort and confirmed its performance and its association with estimated blood loss and surgical complexity in placenta accreta spectrum. Category 3 cases were associated with the highest blood loss and surgical complexity, indicating that transvaginal ultrasound in placenta accreta spectrum scoring may be able to identify severe cases.