Early urethral obstruction sequence: a lethal entity?

Early urethral obstruction sequence (EUOS) is characterized by severe bladder distension by the end of the first trimester of pregnancy, resulting in renal dysplasia or hydronephrosis, oligohydramnios and subsequent lung hypoplasia. We reviewed the outcome of 18 fetuses with suspected EUOS. The mean gestational age at the time of diagnosis was 15 weeks. In 1 fetus, a vesicoamniotic shunt was placed unsuccessfully. Pregnancy was terminated in 11 fetuses and 9 showed signs of pulmonary hypoplasia and severe renal disease on autopsy. In 3 cases, the autopsy material could be evaluated. Premature delivery occurred in 2 patients, and 5 chose to deliver at term. All 7 fetuses died soon after birth because of respiratory failure and lung hypoplasia; renal abnormalities were also found on autopsy. Since it is currently not clear whether prenatal intervention will prevent renal dysplasia and it is not known how early it should be done to prevent pulmonary hypoplasia, we believe that termination of pregnancy should be discussed when EUOS is suspected.