Prenatal diagnosis and management of urethral obstruction.

Eighteen cases of bladder outlet obstruction were diagnosed at Queen Mother's Hospital, Glasgow, over a period of 6 years. Commonest cause was posterior urethral valve in 11 cases (61%). Oligohydramnios was present in 78% of cases with a mortality of 67% mainly due to pulmonary hypoplasia. The 6 surviving infants (33%) underwent early postnatal surgery. Two of these have chronic renal failure on follow-up.