Increased occurrence of ovarian pregnancy

Forty-one cases of ovarian pregnancies diagnosed during 1946 and 1980 were analysed clinically and histologically. All of the pregnancies were terminated during the first trimester. The average duration of amenorrhea was 36.4 +/- 28.6 days; fifteen of the patients (37%) had no amenorrhea. The gestational sac was implanted at the ovarian surface in 30 cases and deeper in the cortex in 11 cases. A close connection with the corpus luteum was noted in 26 cases, with 8 cases showing placental tissue inside the corpus luteum. Endometriosis was found in the affected ovary in 2 cases and acute or chronic inflammatory changes in 4. During the 1970's the number of ovarian pregnancies diagnosed was four times as great as in the 1960's. The share of ovarian pregnancies out of all ectopic pregnancies in this decade was 5.4% and that for the 1960's was 1.5%. Of the patients with an ovarian pregnancy diagnosed in the 1970's, 61% had an IUD in situ at the time of the operation. In addition 61% of these patients had a history of a gynecological operation during a previous pregnancy.