What are the key ultrasound findings that suggest a diagnosis of placenta accreta spectrum in a pregnant patient?

The key ultrasound findings that suggest a diagnosis of placenta accreta spectrum (PAS) in a pregnant patient include several characteristic features.

One significant finding is the loss of the clear retroplacental zone or space (Jauniaux and Bhide, 2017; Horgan and Abuhamad, 2022). The presence of multiple placental lacunae, which are irregular vascular spaces within the placenta, is another strong indicator (Jauniaux and Bhide, 2017; Horgan and Abuhamad, 2022). Additionally, ultrasound may reveal thinning, disruption, or irregularity of the myometrial-bladder interface or uterine serosa-bladder interface (Jauniaux and Bhide, 2017; Horgan and Abuhamad, 2022). Increased vascularity at the myometrial-bladder interface is also a suggestive sign (Jauniaux and Bhide, 2017; Horgan and Abuhamad, 2022). The visualization of bridging vessels, which extend from the placenta into the myometrium or beyond, further supports a diagnosis of PAS (Jauniaux and Bhide, 2017; Horgan and Abuhamad, 2022). On color Doppler, turbulent blood flow within the lacunae can also be observed (Horgan and Abuhamad, 2022).