Primary ovarian ectopic pregnancy misdiagnosed as first-trimester missed abortion

Primary ovarian ectopic pregnancy is an uncommon ectopic gestation. It accounts for 0.5% to 1% of all ectopic gestations, and its incidence ranges from 1 in 7000 to 1 in 40,000 deliveries.(1,2) The clinical appearance varies. It is known to mimic an ovarian tumor or a tubal ectopic pregnancy(3-8) but to be misdiagnosed as an asymptomatic 8-week missed abortion is uncommon and makes this an interesting case. In the literature, there have been sparse case reports of primary ovarian ectopic pregnancy mistaken for intrauterine gestation, some of which progressed to the third trimester.(9-12) We present this case as an example of a misdiagnosed missed abortion and discuss sonographic examination methods to diagnose ovarian ectopic pregnancy.