OC04.06: Management of adnexal masses during pregnancy: a prospective study

Data on the assessment of adnexal masses during pregnancy is limited. Our objective was to evaluate the use of ultrasound as an adjunct to the management of adnexal masses in pregnant women. A prospective study was performed between September 2017 and March 2019 at a London tertiary referral hospital. We only included pregnant women found to have unilateral or bilateral adnexal masses on standardised ultrasonography. IOTA terms and definitions were applied to describe and classify each adnexal mass. A total of 106 women were included, with 77 (73%) diagnosed at 4-15 weeks' gestation. Only 15 (14%) presented with abdominal pain. Maximum diameter ranged from 12 to 210 mm (median diameter: 42 mm). In total, 104 (98%) patients were managed expectantly and two (2%) underwent an operation during pregnancy. One operation was performed during Caesarean section. A second operation was carried out at 12 weeks secondary to abdominal pain. Two further adnexal masses were removed after delivery and one after miscarriage. Histopathologies of the surgically removed masses were: two mucinous cystadenomas, one mature teratoma, and two serous borderline ovarian tumours. Hence, none were diagnosed with invasive cancer. Three operations were performed via laparotomy and two via laparoscopy. 99 (93%) were classified as benign, six (6%) as unclassifiable and one (1%) as malignant at initial assessment according to IOTA Simple Rules. The adnexal mass classified as malignant was found to be a recurrent serous BOT on pathology. 17 (16%) masses spontaneously resolved. One patient presented with cyst rupture during pregnancy and one with adnexal torsion. Use of ultrasonography to manage ovarian pathology avoided unnecessary intervention. Complications were rare and no invasive cancers were diagnosed. Our data are prospective and provide justification for larger appropriately powered studies to define the behaviour of ovarian pathology in pregnancy.