Congenital Hydronephrosis

Ultrasound

• Congenital hydronephrosis is often first identified during routine fetal screening. Postnatal ultrasound is essential to confirm the diagnosis and assess the severity after birth.

Voiding Cystourethrogram (VCUG)

• Recommended for patients with suspected vesicoureteral reflux (VUR) or lower urinary tract obstruction. This test visualizes urine flow from the bladder and can detect reflux or anatomical abnormalities.

Diuretic Renal Scan (MAG3 or DTPA)

• Used to evaluate urinary drainage and differential renal function, helping determine the degree of obstruction and whether surgical intervention is needed.

Blood and Urine Tests

• These assess overall kidney function and help detect urinary tract infections (UTIs) or other complications.

Hydronephrosis is graded based on ultrasound findings. Several staging systems are used to assess the severity, including:

• Society for Fetal Urology (SFU) Grading System: Categorizes hydronephrosis from Grade 0 (normal) to Grade 4 (severe dilation with thinning of the renal parenchyma).
• Anteroposterior Renal Pelvic Diameter (APRPD): Measures the width of the renal pelvis; commonly used in prenatal assessments.
• Urinary Tract Dilation (UTD) Classification: A standardized postnatal system that considers renal pelvic diameter, calyceal dilation, parenchymal appearance, and ureter/bladder abnormalities.

These grading systems help guide follow-up, determine the need for further testing, and support clinical decision-making.

1. Observation

• Most mild to moderate cases resolve spontaneously
• Periodic imaging to monitor kidney growth and function

2. Prophylactic Antibiotics

Used selectively to prevent urinary tract infections, especially in infants with reflux

3. Surgical Intervention

Required if there is significant obstruction or decreased kidney function