[Therapeutic approach in a fetus with posterior urethral valves]

A pregnant woman was diagnosed with fetal uropathy at 18 weeks gestation. A thorough examination revealed bilateral hydronephrosis, megacystis with bladder neck and posterior urethral dilatation, normohydramnios, normal echocardiography and normal male karyotype. From the 20th week on she developed a progressive oligohydramnios, and the left kidney became hyperechogenic. Fetal urine analysis at week 21 showed hypotonic urine in both renal pelvises, and a beta 2 microglobulin of 8.5 mg/l. on the right side and 18 mg/l. on the left one, suggesting some degree of function on the right kidney. A vesico-amniotic shunt was placed at week 22, which was ineffective, and another shunt was placed two weeks later. Twenty-four hours later the bladder size decreased, but amniotic fluid did not increase and a great amount of ascitis developed, which was attributed to catheter migration. On week 25, the abdomen was decompressed through a peritoneal-amniotic shunt. Ascitis decreased thereafter, but oligohydramnios remained unchanged. The patient died 20 hours after a cesarean section was performed at the 31st week. The necropsy diagnoses were: posterior urethral valves, bilateral renal dysplasia and pulmonary hypoplasia. This case illustrates the difficulty in establishing a prognosis based on the prenatal data available at present.