The role of ultrasound imaging in the management of partial placental retention after third trimester livebirth

Abstract

Objectives: To evaluate the impact of different ultrasound signs in the management and the role of ultrasound guidance in the surgical evacuation of partial placental tissue retention.

Methods: This is an observational cohort study and retrospective case assessment of 82 patients with clinical symptoms of partial placental retention following a third trimester singleton livebirth between January 2013 and May 2019. The ultrasound signs were recorded using a standardized protocol and the outcome of the management strategy and the use of ultrasound guidance during any surgical procedure was evaluated.

Results: Out of the 64 patients who had a vaginal birth, 25 (39.1%) had a manual removal of the placenta at delivery. Fifteen patients were confirmed as not having retained placental tissue and did not require further treatment. Four patients were referred after failed surgical management and four after failed conservative management. All surgical procedures were vacuum aspiration and forceps removal under continuous ultrasound guidance. A significantly lower gestational age at delivery (p < .05), shorter interval between delivery and ultrasound diagnosis (p < .05) and lower number of patients presenting with heavy bleeding was found in the conservative compared to the surgical management subgroups (p < .05). The incidence of feeding vessels was significantly (p < .05) higher in the surgical than in the conservative management subgroups and associated with increased myometrial vascularity. Six patients developed intra-uterine adhesions. In four of these cases, ultrasound examination showed a hyperechoic mass surrounded by normal myometrial vascularity and no feeding vessel.

Conclusions: Ultrasound imaging accurately differentiated between patient with and without partial placental retention after third trimester livebirth. Ultrasound-guided vacuum aspiration is safe and efficient in these cases.

Keywords: Ultrasound imaging; conservative management; placental retention; surgical management.