Ovarian hyperstimulation syndrome associated with fetal trisomy 21.

We report a case of ovarian hyperstimulation syndrome associated with fetal trisomy 21. A primigravida presented at 17 1/7 weeks of gestation with abdominal pain because of enlarged ovaries. Multiple fetal abnormalities were seen on pregnancy ultrasound. Fetal trisomy 21 was diagnosed by amniocentesis. The patient's human chorionic gonadotropin level was markedly elevated, as often occurs with fetal trisomy 21, and was likely associated with the ovarian hyperstimulation. Ovarian hyperstimulation syndrome associated with fetal aneuploidy has not been previously described.