Intrauterine pregnancy following transperitoneal oocyte and/or sperm migration in a woman with an ectopic (undescended) ovary

This is the first report of an intrauterine pregnancy following timed coitus, resulting from transperitoneal sperm and/or oocyte migration as the oocyte originated from an ectopic (undescended) ovary. The patient was treated in the infertility clinic after a history of primary infertility for 2 years. Diagnosis of a moderate teratozoospermia and the presence of a unicornuate uterus with one right-sided normal ovary was made. During the first intrauterine insemination (IUI) treatment cycle with clomiphene citrate stimulation, a discrepancy between oestradiol concentrations and follicular growth was observed. Magnetic resonance imaging (MRI) was carried out because the presence of an ectopic ovary was suspected. The diagnosis of a left-sided undescended ovary was made, containing several follicles, the largest measuring 16 mm in diameter. Because of a spontaneous LH surge 2 days later without substantial follicular growth in the normal right-sided ovary, IUI was cancelled and timed intercourse was planned. Surprisingly, and although the largest follicle in the normally located ovary reached a maximum diameter of only 12 mm on repetitive ultrasound monitoring, this patient became pregnant and gave birth to a healthy baby boy.