Abstract

Congenital hydronephrosis is the most common encountered kidney malformation at detailed ultrasound carried out at 18 weeks of gestational time of occurence, unilaterality or bilaterality, the presence of associated anomalies and the amniotic fluid volume are factors which affect the fetal prognosis. Left-sided mild hydronephrosis which was detected at one of the fetuses in a twin pregnancy at 18 weeks gestation progressed parallel to the gestational age and advanced to moderetaly-severe degree with caliceal and uretal dilation. After delivery it was observed to have regressed totally by 13 months of age. The factors which have roles in the prognosis of the hydronephrosis are discussed.