Newborn with an abdominal cyst on prenatal US

US of neonatal ovarian cyst and a uterus under maternal stimulation of estrogen
Transverse US of the pelvis shows the fluid-filled bladder on the anterior right side of the image with a uterus with a thickened myometrium and prominent central endometrial stripe located just posterior to it. A large anechoic structure without septations is seen in the left side of the image and was felt to be associated with the right ovary.

The diagnosis was a right neonatal ovarian cyst and a uterus under maternal stimulation of estrogen.