Question

A newborn baby has been diagnosed antenatally with hydronephrosis. What is the diagnostic approach, steps of management, and follow-up of this baby?

Hint:

Timely intervention and regular follow-up are crucial in managing hydronephrosis in newborns to prevent long-term renal damage.

Answer 1

Hydronephrosis is a common condition detected during routine antenatal ultrasounds. It refers to the dilation of the renal pelvis and calyces due to impaired urine flow. Proper diagnostic evaluation, management, and follow-up are critical to prevent complications such as renal damage.
Step 1: Diagnostic Approach:
1. Confirmatory Ultrasound:
- A postnatal ultrasound is the first step to confirm the diagnosis and assess the severity of hydronephrosis. The degree of hydronephrosis is classified based on the anteroposterior renal pelvic diameter (APD).
- If APD is greater than 7-10 mm, further evaluation is warranted.
2. Voiding Cystourethrogram (VCUG):
- If vesicoureteral reflux (VUR) is suspected (a common cause of hydronephrosis), a VCUG is done to assess the bladder and urethra for reflux of urine from the bladder back into the kidneys.
3. Magnetic Resonance Urography (MRU):
- In cases where the etiology is unclear or when anatomical anomalies like obstruction or pyeloureteral junction (PUJ) stenosis are suspected, MRU may provide more detailed imaging.
4. Renal Scintigraphy:
- In some cases, a renal scan with technetium-99m dimercaptosuccinic acid (DMSA) or mercaptoacetyltriglycine (MAG3) is used to assess renal function and perfusion.

Step 2: Management:
1. Observation:
- In cases of mild hydronephrosis, particularly if there is no evidence of infection or other complications, conservative management with regular monitoring via ultrasound may be appropriate.
- Follow-up ultrasounds every 6-12 weeks are recommended to monitor the progression.
2. Medical Treatment:
- If urinary tract infection (UTI) is suspected or confirmed, appropriate antibiotic treatment should be initiated. Antibiotic prophylaxis is often started for infants with significant hydronephrosis or VUR to prevent UTIs.
3. Surgical Treatment:
- Surgical intervention may be required for significant hydronephrosis caused by obstructive uropathy (e.g., PUJ obstruction or posterior urethral valves).
- Procedures may include pyeloplasty for PUJ obstruction or valve ablation for posterior urethral valves.
4. Management of VUR:
- For infants with significant VUR, surgical correction may be necessary, although many mild cases resolve spontaneously. In some cases, endoscopic injection of bulking agents is an option.

Step 3: Follow-up:
1. Regular Ultrasound Monitoring: - Follow-up ultrasounds should be scheduled to monitor the resolution of hydronephrosis or any progression of kidney damage.
- Monitoring is especially important for the first 2 years of life as the renal system matures.
2. Urological Consultation:
- Infants with moderate to severe hydronephrosis, especially those with VUR, should be referred to a pediatric urologist for further management.
3. Renal Function Monitoring:
- Regular renal function tests (creatinine, urea) and blood pressure checks should be done to assess kidney function, especially if surgery or significant hydronephrosis is present.
4. Long-Term Follow-Up:
- Even after successful treatment, some children may need long-term follow-up into childhood to ensure normal renal function and prevent complications like hypertension or renal insufficiency.