Surgically confirmed adnexal torsion during pregnancy: Does the trimester make a difference?

To investigate the clinical and the sonographic characteristics of adnexal torsion (AT) during pregnancy and to underline differences in AT manifestation between pregnancy trimesters.This is a retrospective cohort study in a tertiary medical center. The study included all pregnant women with surgically confirmed AT between March 2011 and April 2020. The patients were divided into three groups according to pregnancy trimesters, and the clinical and sonographic characteristics were compared between the groups.The study cohort included 140 cases of AT. Ninety-nine (70.7%) of the cases occurred during the 1st trimester, and 31 (22.1%) and 10 (7.1%) occurred during the 2nd and the 3rd trimesters, respectively. Conception by assisted-reproductive technologies (ART), nausea, and finding of enlarged ovary on ultrasound scan were all more common among patients in the 1st trimester group as compared to the 3rd trimester group (p = 0.001, 0.015, and 0.024, respectively). The mean time from admission to surgery was significantly shorter in the 1st trimester group as compared to late pregnancy (p = 0.001). The majority of cases were right-sided. There was a significant difference in the organs involved in every trimester of pregnancy-ovary only, ovary and fallopian tube, and fallopian tube only (p = 0.023).Most AT cases during pregnancy occurred during the 1st trimester. Conception by ART and enlarged ovary on ultrasound scan were also more common in AT cases during early pregnancy. Time from admission to surgery was longer as pregnancy progressed and organs involved differed between trimesters. Understanding the difference in manifestation of AT in every trimester might improve the preoperative evaluation of AT in pregnancy.