Prevalence:

• 1 in 10,000 births.

Ultrasound diagnosis:

• Presence of hydroureter and hydronephrosis with normal bladder.
• The dilated ureter is tortuous and appears as a collection of cysts of variable size, localized between the dilated renal pelvis and the bladder.
• The etiology is diverse, including ureteric stricture or atresia, vascular obstruction, diverticulum, or ureterocele. Ureteroceles (visible as a thin-walled and fluid-filled small circular area inside the bladder) are usually found in association with a duplex kidney and collecting system. The upper pole characteristically obstructs and the lower one refluxes.

Associated abnormalities:

• The incidence of chromosomal abnormalities and genetic syndromes is not increased.

Investigations:

• Detailed ultrasound examination.

Follow up:

• Ultrasound scans every 4 weeks to monitor the evolution of hydronephrosis and assess amniotic fluid volume.

Delivery:

• Standard obstetric care and delivery.

Prognosis:

• Postnatal intervention is indicated if the vesico-uretric reflux is associated with abnormal renal function.

Recurrence:

• No increased risk of recurrence.