Perinatal management of fetal hydronephrosis with normal bladder.

This report covers 30 cases of prenatal diagnosis of uni- or bilateral hydronephrosis not associated with an overdistended bladder. Oligohydramnios was observed only in four cases while polyhydramnios occurred in three affected fetuses. In no case was fetal urine aspirated or drained prenatally. Early delivery was performed in four cases with oligohydramnios. Sixteen newborns required surgical correction of the lesion as it was confirmed by urography, following at least two sonographic examinations which confirmed a moderate to severe hydronephrosis after birth. The most frequent lesion was pyelo-ureteric junction obstruction (12 cases). Thirteen cases were normal at follow-up, and in two of these the dilation cleared up during intrauterine life. One case of severe hydronephrosis proved to be a multicystic kidney. In this series isolated hydronephrosis, both uni- or bilateral did not result in fetuses being at high risk for survival (only one infant died after surgery) nor as regards to associated malformations and perinatal morbidity. Provided a properly timed surgical correction was performed, renal function resulted to be good at follow-up.