Three years' experience with large ovarian cysts diagnosed in utero.

Thirteen fetuses with abdominal cystic tumors were diagnosed by routine prenatal ultrasonography between the 28th and 36th week of gestation. Postnatal ultrasonography of the full-term newborns confirmed the findings. Laparotomies were performed in all cases except one. Patients who were operated on had large ovarian pseudocysts with volumes between 24 and 120 cc. In seven patients (54%), the cysts arose from the left ovary; this included four cases in which the postnatal ultrasound was interpreted as showing the cysts in the right abdomen. Very thin cystic walls threatening perforation were found in 91%. In 33%, we found salpingotorsion on the affected side. Small contralateral ovarian cysts were found in 66% of the patients. One infant required resection of 30 cm of necrotic jejunum because adhesions to the cyst had caused bowel volvulus. Histology of the cysts showed hemorrhage and calcifications, but ovarian stroma was absent in all but one patient. Serum estradiol-17 beta, progesterone follicle-stimulating hormone, and luteinizing hormone were normal in all cases, and similar levels were found in the cyst fluid. These results show that large abdominal cystic masses in full-term infant girls with normal gonadotrophin levels and normal serum estradiol-17 beta and progesterone levels are very likely to require surgery; this is in contrast to preterm neonates with elevated gonadotrophins who can be treated with medroxyprogesterone acetate in the absence of clinical signs necessitating surgery.