Antenatal Hydronephrosis

The widespread use of ultrasonography during pregnancy has resulted in a higher detection rate for antenatal hydronephrosis.This is one of the most common birth defects detected (1-3%).The most common causes of antenatal hydronephrosis are transient hydronephrosis, ureteropelvic junction obstruction, and vesicoureteral reflux.It can be detected as early as the 12 th to 14 th week of gestation and in addition, ultrasonography performed in the third trimester (28 to 34 weeks gestation) has been suggested to be more helpful in predicting postnatal outcome.The Society of Fetal Urology grading and renal pelvic diameter grading systems have been developed to diagnose and grade the severity of antenatal hydronephrosis.If dilatation is detected, ultrasound should focus on: laterality, severity of hydronephrosis, echogenicity of the kidneys, hydronenephrosis or hydro-ureteronephrosis, bladder volume and bladder emptying, sex of the child and amniotic fluid volume.They are helpful in determining the cause of hydronephrosis.To date, the reported long-term outcomes of antenatal intervention for severe obstructive uropathy are mixed.The goal of prenatal management is to detect those cases, which will impact the health of the infant and require antenatal and postnatal evaluation and possible intervention to minimize adverse outcomes.Postnatal evaluation includes physical examination and the use of radiologic studies to determine the cause of hydronephrosis and then treatment should focus on this.The main goal of this review is to evaluate and summarize the antenatal hydronephrosis.(JAREM 2013; 3: 60-5)