Ultrasonic evidence for luteinization of unruptured preovulatory follicles

Luteinization of an unruptured ovarian follicle has been reported as a cause of infertility and has heretofore been diagnosed only by direct visualization of the ovarian surface. Four patients who demonstrated defects in ovulation requiring therapy to induce ovulation and who were not achieving desired conception despite apparently adequate treatment were studied with serial pelvic ultrasonic examinations for 17 cycles. Luteinization, characterized by the loss of a clear demarcation of the follicular cyst wall and the presence of intrafollicular echoes, was suspected in each of these cycles by the absence of ultrasonic signs of ovulation--that is, a rapid decrease in follicular size and the appearance of free fluid in the cul-de-sac. Histologic confirmation of a persistent luteinized cyst is presented.