Antenatal renal pelvic dilatation; the long-term outlook

Area of Science:

• Pediatric Nephrology
• Diagnostic Imaging
• Urology

Background:

• Antenatal hydronephrosis is a common finding in infants.
• Accurate prognosis and timely diagnosis of urinary tract abnormalities are crucial for optimal outcomes.
• Selective use of micturating cystourethrogram (MCUG) requires careful consideration to avoid missing significant pathology, such as vesicoureteric reflux (VUR).

Purpose of the Study:

• To provide data for improved parental counseling regarding prognosis in infants with antenatal hydronephrosis.
• To validate a selective policy for performing MCUG to ensure significant pathology, particularly VUR, is not missed.

Main Methods:

• Prospective data collection over 6 years.
• Inclusion of infants with renal pelvic diameter (RPD) ≥ 5 mm on pre and postnatal imaging.
• Review of imaging records for pathology detected after symptom re-presentation, with age at review ranging from 2-8 years.

Main Results:

• Risk of significant pathology correlated with antenatal RPD severity, ranging from 6% (RPD 5 mm at 20 weeks) to 38% (RPD 10 mm).
• At 28-33 weeks gestation, risk varied from 5% (RPD 5 mm) to 15% (RPD 10 mm).
• A selective MCUG policy identified only one case of grade II VUR missed within the study population.

Conclusions:

• The study provides valuable prognostic information for antenatal and postnatal counseling of parents.
• A selective MCUG policy is deemed appropriate and effective in managing infants with antenatal hydronephrosis.
• This approach balances diagnostic yield with resource utilization, reassuring clinicians and parents.