OP09.01: Transvaginal ultrasound‐guided feticide in the management of interstitial ectopic pregnancy

To assess the effectiveness and safety of transvaginal ultrasound-guided feticide in the treatment of interstitial ectopic pregnancy (IEP). A retrospective study of all patients with an IEP at a New York City academic institution between 2010-2023. Those who underwent cornual resection as primary therapy were excluded. Live IEP cases received ultrasound-guided feticide with potassium chloride and/or methotrexate (MTX). Non-live IEPs received systemic MTX or were managed expectantly. Primary outcome was treatment success, defined as resolution without surgical intervention. Secondary outcomes were complication rate (including hemorrhage, sepsis, blood transfusion or uterine rupture), β-hCG trend, and time to sonographic resolution. Out of 27 total IEP patients, 23 were included in our study; four patients received cornual resection as primary therapy and were excluded. Mean maternal age was 32.4 ± 1.5 years and mean gestational age at diagnosis was 6.3 ± 0.2 weeks. Twelve patients (52.2%) had a live IEP; 10/12 (83%) underwent transvaginal ultrasound-guided feticide, all with complete IEP resolution. Median bHCG decline in the first week following treatment was 38.4% (±41.8), median (IQR) interval to negative bHCG was 8.0 (6.8) weeks, and median (IQR) interval to complete sonographic resolution was 9.0 (6.5) weeks. Two patients (17%) declined the procedure and received systemic MTX alone; one was complicated by uterine rupture and treated with surgery, and the second resolved after treatment. 11 patients (47.8%) had a non-live IEP, 3/11 (27.3%) had expectant management and 8/11(72.7%) received systemic MTX treatment; all had complete IEP resolution. Transvaginal ultrasound-guided feticide is a highly effective and safe approach for managing live IEPs, showing promising results with minimal complications.