ObjectivesAim of this study was to assess the ultrasonographic, epidemiological, clinical, and evolutive characteristics of enhanced myometrial vascularity (EMV) that follows a first trimester termination of pregnancy/management of non‐viable pregnancy.MethodsIn this study we planned to include women who attented to a follow‐up ultrasound 5 to 6 weeks after a first trimester termination of pregnancy (TOP) or after management of a first trimester non‐viable pregnancy. EMV was characterized by two‐ and 3‐dimensional ultrasound features and Virtual Organ Computer Aided Analysis. Ultrasonographic diagnosis of EMV was made when high flow myometrial vessels projecting to the endometrium were observed, while an abnormal junctional zone, an absent endometrial midline and heterogeneous endometrial echogenicity supported the diagnosis. Patients with EMV underwent an expectant management with a planned ultrasonographic follow‐up every two weeks until resolution.ResultsIn the study period, 305 women were diagnosed with TOP, of which 132 later attended to the initial follow‐up at 5‐6 weeks and, among them, 52 were diagnosed with EMV. Correspondingly, 96 women were managed for a non‐viable pregnancy, whose 32 showed up at the follow up and 6 had a diagnosis of EMV. Overall, 164 of 401 women were included in the study and EMV was identified in 58 of them (35%). The expected prevalence of EMV 5‐6 weeks after a TOP is therefore something between 52/305 (17%) and 52/132 (39%) and that after the management of a non‐viable pregnancy something between 6/96 (6%) and 6/32 (19%). Bleeding/pelvic pain was present in half of women with EMV (29/58) and serum HCG was detectable in 29.3% (17/58). All cases with EMV presented exuberant vessels projecting from the myometrium towards the endometrium at the ultrasound assessment, along with the absence of the endometrial midline (98%), abnormal junctional zone (97%)(64% interrupted, 33% irregular), a non‐uniform heterogeneous endometrium (96%) with the frequent presence of cystic areas (67%). Most women with EMV were multiparous (67%), and 89.6% of them had performed a TOP. The medical management was more frequent in women with than without EMV (93.1% vs. 77.4%; p=0.023). Upon multiple regression analysis, the risk of EMV was increased by TOP vs. non‐viable pregnancy (OR 3.67, 95%CI 1.16‐11.56; p=0.026), and by multiparity (OR 2.95, 95%CI 1.45‐6.01; p=0.002).All women were managed expectantly. Eleven did not return to the subsequent follow‐ups nor to our outpatient or emergency facilities. A spontaneous resolution of the lesions was observed within 7 to 16 weeks in 95.7% (45/47) of the remaining cases. In the 2 women that underwent to surgery for pelvic discomfort, histology showed the presence of neo‐vessels mixed with retained chorionic villi.ConclusionEMV is a transient and common finding 5‐6 weeks following first trimester TOP or management of non‐viable pregnancy. TOP and multiparity represent risk factors. Expectant management is appropriate, as EMV spontaneously resolves in almost all cases without complications within 2‐4 months.This article is protected by copyright. All rights reserved.