Posterior urethral obstruction: Prenatal sonographic findings and clinical outcome in 12 cases

Twelve cases of fetal urethral obstruction were reviewed retrospectively. A dilated posterior urethra was identified in eight fetuses (67%) and an enlarged bladder in 11 (92%). Ureterectasis, pyelocalicectasis, increased renal echogenicity, and renal cysts suggest abnormal renal development. Ureterectasis was demonstrated in seven fetuses (58%) and pyelocalicectasis in ten (83%). Renal echogenicity was increased in eight of ten cases (80%) and renal cysts were identified in two cases. Decreased amniotic fluid volume complicated ten pregnancies (83%). There were six live births, but only two neonates survived more than 5 weeks. Pulmonary immaturity contributed to the four postnatal deaths