VP46.22: The value of sonographic markers in the management of placenta accreta spectrum disorders

To assess the value of ultrasound assessment in placenta accreta spectrum (PAS) at a single institution. A retrospective cohort study was conducted on cases identified at risk for PAS from January 2013 and July 2019 at a single institution. Ultrasound (US) reports interpreted by Maternal-Fetal Medicine specialist were collected from the patient's medical record and reviewed. Five characteristic findings known to be associated with PAS were extracted from these reports: the presence of placental lacunae, the loss of sonolucency/clear space, disruption of bladder and myometrial interface, increased or disorganised vascularity and invasion of pelvic structures by placental tissue. The US markers were analysed by the presence of histopathology confirmed PAS. Statistical analysis was performed using chi square and Fisher's exact test. Statistical significance was set at p ≤0.05. Ultrasound reports were reviewed of the 72/77 patients in the cohort that underwent US. Individual ultrasound markers were not significantly associated with presence of PAS confirmed at delivery. The relationships between US in predicting PAS were also analysed using combinations of US markers. The presence of the loss of the bladder and myometrial interface and increased or disordered vascularity was associated with confirmed PAS at delivery (p = 0.49). In our patient population, no single US finding was associated with confirmed PAS at delivery. However, when markers were combined, the presence of disruption of bladder and myometrial interface and increased/disorganised vascularity was associated with increased risk for PAS. In conclusion, risk factors for PAS and the presence of multiple ultrasound findings associated with PAS lead to increased recognition of these cases.