Early urethral obstruction sequence (EUOS) is characterized by severe
bladder distension by the end of the first trimester of pregnancy, res
ulting in renal dysplasia or hydronephrosis, oligohydramnios and subse
quent lung hypoplasia. We reviewed the outcome of 18 fetuses with susp
ected EUOS. The mean gestational age at the time of diagnosis was 15 w
eeks. In 1 fetus, a vesicoamniotic shunt was placed unsuccessfully. Pr
egnancy was terminated in 11 fetuses and 9 showed signs of pulmonary h
ypoplasia and severe renal disease on autopsy. In 3 cases, the autopsy
material could be evaluated. Premature delivery occurred in 2 patient
s, and 5 chose to deliver at term. All 7 fetuses died soon after birth
because of respiratory failure and lung hypoplasia; renal abnormaliti
es were also found on autopsy. Since it is currently not clear whether
prenatal intervention will prevent renal dysplasia and it is not know
n how early it should be done to prevent pulmonary hypoplasia, we beli
eve that termination of pregnancy should be discussed when EUOS is sus
pected.