Ultrasound features help identify patients who can undergo noninvasive management for suspected retained products of conception: a single institutional experience.

To evaluate ultrasound (US) features associated with successful noninvasive management for suspected retained products of conception (RPOC). In this IRB-approved retrospective study, the radiology report database was queried for pelvic US with keywords of postpartum hemorrhage (PPH) and/or RPOC over a 2-year period. Follow-up exams, US exams without clinical follow-up, suboptimal image quality, and > 1 year from delivery or pregnancy termination were excluded. Charts were reviewed for clinical presentation and management. Two radiologists reviewed images for endometrial thickness, endometrial echogenicity, endometrial vascularity, and enhanced myometrial vascularity (EMV), as well as inner myometrial peak systolic velocity (PSV) and resistive index (RI) where available. Features were assessed for associations with management approach, and test characteristics were calculated. Initial query yielded 196 exams, and 48 were excluded. A total of 148 patients were included. Mean age was 34.2 years (21-47), and mean time from delivery or pregnancy termination was 40.4 days (0-223). 81 (55%) underwent noninvasive management: 72 (48%) expectant and 9 (6%) medical. 67 (45%) underwent invasive management: 60 (41%) surgical and 7 (5%) uterine artery embolization. There was substantial inter-reader agreement for assessment of EMV (K = 0.78) and endometrial vascularity (K = 0.72). Thin endometrial stripe, avascular endometrium, and absence of EMV were associated with successful noninvasive management (p < 0.05). Thin endometrium (< 10 mm) had specificity (90%), PPV (88%), and likelihood ratio (5.91) in predicting successful noninvasive management. Endometrial thickness < 10 mm, avascular endometrium, and absence of EMV are the sonographic features associated with successful noninvasive management for PPH or suspected RPOC.