Ovarian pregnancy; relationship to an intrauterine device.

Ovarian pregnancy is a rare form of ectopic pregnancy in which the gestational sac is implanted within the ovary. The incidence is 0.5 to 3% of all ectopic gestations. In contrast to patients with tubal pregnancies, traditional risk factors, such as pelvic inflammatory disease and prior surgical procedure upon the pelvis, may not play a role in the aetiology. In the 2 cases reported here, it seems that using an intrauterine contraceptive device was an important factor.