Identification of Placenta Accreta Spectrum: A Case Series

Background: Technological advancements continue to increase the antenatal suspicion and diagnosis of placenta accreta spectrum (PAS) prior to delivery. Therefore, further understanding is needed regarding the characteristics and outcomes in preparation for continued expected growth in the number of cases and to better prepare providers for care of the complexity of care in providing for these patients. The purpose of this study is to review outcomes and maternal characteristics for cases with suspected PAS at a tertiary care center. Methods: This is a retrospective case series performed at The University of Louisville from January 2024 through March 2025 with a review of patients with suspected PAS. All cases were delivered at a single site. Outcomes reviewed included antepartum care (consults, ultrasound findings, maternal obstetric/surgical history), operating room care (estimated blood loss, units of RBC transfusion, operative complications) and final pathology. Demographics and clinical factors were summarized and compared by CS history (one or fewer previous CS vs 2 or more) using two-sample test for continuous, Fisher exact for categorical, and Mann-Whitney test for non-parametric features. Results: A total of 17 cases over a 15-month period were identified for suspected PAS. The average maternal age was 33.7 years. Patients had a range of 2 to 14 prior pregnancies. All patients except one had at least one prior cesarean section (1CS= 7, 2CS= 6, 3+CS= 4). The average gestational age at time of delivery was 34 weeks and 3 days. Average birth weight was 2344.44g. 88.2% of infants were admitted to the Neonatal Intensive Care Unit (NICU) following delivery with 23.5% requiring intubation, 64.7% CPAP, and 11.7% remaining on room air. The average length of admission was 22 days, with two infants requiring transfer for higher level of pediatric care. 94.1% of patients had ultrasound evaluation with Maternal-Fetal Medicine at our institution, and 88.2% obtained a MRI to confirm diagnosis. Placenta previa was present in 14 cases (73.7%.). Imaging was sorted based on suspected degree of placental invasion with 10 suspected accreta cases (52.6%), 5 suspected increta cases (26.3%), and 2 suspected percreta cases (10.5%). There was one patient with PAS not suspected on imaging at outside institution with an accreta present at the time of delivery. In 5 cases, PAS was not confirmed at the time of delivery (26.3%). Of those cases that were confirmed at time of delivery, 5/13 (38.5%) were consistent with imaging suspicion, 5/13 (38.5%) had a higher level of placenta invasion, and 3/13 (23.0%) had a lower level of invasion. The average blood loss during these deliveries was 1200ml with 9 patients requiring receipt of blood products. The average number of blood products received was 2 units. Only 3 patients had ureteral injury at the time of delivery, with one of those being intentional injury due to extent of placental invasion. Re-operation was needed in one patient due to continued intra-abdominal bleeding. Overall, there was no statistically significant in patient outcomes based on number of prior cesarean sections. The cohort was further divided into 1 or less cesarean section vs multiple cesarean sections with no statistical significance in maternal blood loss, receipt of blood products, ureteral injury or need for re-operation. There was also no statistical significance in neonatal weight or APGAR scores at delivery. Discussion: An extensive review of the 17 cases was performed including characteristics of our patient population, operative findings and severity of disease, radiographic findings consistency with pathology, and infant outcomes. Of particular interest is the rise of accreta cases after only one prior cesarean in our case population. Case statistics will continue to aid in guiding informed care for future accreta patients at our institution. We feel that our imaging correlates well with pathology evaluations, and this information is used for continued improvement in diagnosis.