Prenatal sonographic diagnosis of bladder outlet obstruction caused by a ureterocele associated with hydrocolpos and imperforate hymen.

We report a case of prenatal bladder obstruction due to a single system ureterocele associated with hydrocolpos. Ultrasound at 22 weeks demonstrated an enlarged bladder. Serial scans showed progressive ipsilateral obstructive uropathy, contralateral hydronephrosis, and oligohydramnios. Neonatal endoscopic decompression and hymenotomy was performed with residual decreased ipsilateral renal function and dilation. Prenatal bladder obstruction may cause permanent renal damage.