Ovarian hyperstimulation syndrome in preterm infants

Ovarian cysts are a relatively frequent finding in fetuses and neonates. In preterm infants, a simultaneous occurrence of estradiol-producing ovarian cysts and edematous swelling of the vulva, the thighs and the lower abdominal wall was described by Sedin and co-workers in 1985 for the first time. This ovarian hyperstimulation syndrome occurred at a postconceptional age that slightly preceded the expected time of delivery. We report on four extremely low birth weight infants who were observed in the neonatal ward with ovarian cysts and stimulation of the external and internal genitalia, beginning at a postconceptional age of 35 to 39 weeks. The serum concentration of estradiol was within or above the range of the preovulatory peak of adults in all patients. Other causes of edema in preterm infants were excluded. The findings receded during 5 - 9 weeks. It is supposed, that in some cases the physiologically high concentration of gonadotropins in preterm infants stimulates the ovaries to produce ovarian cysts as well as to secrete high amounts of estradiol. This induces a transient stimulation of the external and internal genitalia as in idiopathic or transient precocious puberty.