I have 3 questions on exam justification in pediatric uroradiology for my fellow trainees and radiologists (Reference: Grainger& Allison's Diagnostic Radiology 5th Ed. : pg 1541-3. Please shed some light on the rationale behind whichever approach you consider reasonable.

OBS US detects Prenatal renal pelvic dilatation(RPD)
What next? (watch n wait vs. intervention)

Difference in investigation protocol for unilateral vs. bilateral RPD?

Next step in management of RPD detected prenatally, and postnatal US is normal (no intervention vs. MCU vs. antibiotics only)

Well the book does say that after birth if US still shows unilateral RPD then proceed for MAG3 renogram and follow up US (up until the age of 15-20 yrs). And for Bilateral RPD do the same but also include MCUG and GFR estimation.
And the decision to intervene I suppose depends upon the individual scenario and whether the problem is stable or worsening.
I recently came across an 11 months old boy with the following MCUG showing grade II reflux. DMSA scan showed scarred right kidney. Paediatrician is treating him with prophylactic antibiotics. There is evidence to suggest that even grade 4 reflux stops without any intervention by the age of 2 years.
However in this case there is ectopic insertion of the right ureter as well that may require reimplantation. I am still following this case.

very nice image!