Ultrasonographic diagnosis of severe placental invasion

Abstract

Aim: Placental invasion is a life-threatening obstetric complication. The aim of this study was to identify the optimal ultrasonographic (US) criteria for placenta increta/percreta in order to improve diagnostic accuracy.

Methods: In a retrospective diagnostic study, all 116 patients at Peking University Third Hospital who had been diagnosed with placental invasion from October 2006 to October 2013 were included. Depending on their clinical and/or histopathological diagnosis, the study was divided into two groups: the Placenta Accreta Group (63 cases) and the Placenta Increta/Percreta Group (53 cases). The US images were analyzed for differences between placenta accreta and placenta increta/percreta.

Results: The sonographic criteria found to have predictive value for placenta increta/percreta using a regression model were: deficiency of retroplacental sonolucent zone and/or segmental retroplacental myometrial thinning less than 1 mm, multiple vascular lacunae presenting a 'moth hole' appearance, and placenta previa. Using a cut-off point of 0.589, the sensitivity and specificity were 81.1% and 77.8%, respectively. The area under the receiver-operator curve was 0.848 (P < 0.001).

Conclusion: US diagnosis not only allows the detection of placental invasion, but also facilitates preliminary classification. The three aforementioned criteria facilitate the identification of placenta increta/percreta for precise and comprehensive clinical decision-making.

Keywords: diagnostic study; placenta accreta; placenta increta; placenta percreta; sensitivity and specificity; ultrasonography.