The classification and management of adnexal masses identified in pregnancy

Evaluate the natural history of adnexal masses in pregnancy and the performance of benign Simple Descriptors (SD) and the Assessment of Different NEoplasia's in the adneXa (ADNEX) model, in a two-step strategy for the classification of adnexal masses identified in pregnancy. Retrospective analysis of prospectively collected data of women diagnosed with an adnexal mass on ultrasound (USS) during pregnancy at Imperial College Healthcare NHS Trust between January 2017-November 2022. Relevant clinical data, including age, gestation and complications were extracted. Adnexal masses were classified according to SD as the first step, where SD were not applicable, ADNEX (10% cut-off) was then applied. The endpoint was the subjective assessment on postnatal USS or histology, where available. 254 women (median age 33) were included at a median gestation of 12 weeks. Spontaneous resolution occurred in 25.9%, and 8.3% were lost to follow-up. Decidualisation occurred in 29.8% of endometriomas. Antenatally, benign SD were applicable in 176 (69.3%) masses; one (0.6%) borderline ovarian tumour (BOT) was misclassified. The two-step strategy had a sensitivity of 55.6% and a specificity of 92.7%. Postnatally, benign SD were applicable in 111 (65.7%) masses; one (0.9%) BOT was misclassified. The two-step strategy had a sensitivity of 50.0% and a specificity of 96.9%. In pregnancy and postnatally, 2.2% had a cyst-related complication: two ruptures at 11 and 30 weeks and three torsions, one at 9 weeks and two postnatally. Four had a cystectomy at Caesarean section, three for suspected BOTs (one was confirmed as a BOT). Our data supports expectant management of adnexal masses in pregnancy, given the high spontaneous resolution rate, low prevalence of complications and malignancy. SD can accurately classify benign masses in pregnancy; however, the small number of malignancies (3.9%) limited the evaluation of the two-step strategy. A larger multicentre prospective study is required to achieve this.