One of the most common findings on a prenatal ultrasound in an infant who is otherwise well is renal pelviectasis. Knowing who (and when) to screen is critical in evaluating infants with this diagnosis.
Screening and Management Recommendations
- Most children with this diagnosis will have a benign course
- Some suffer renal deterioration due to infection or obstruction
- The incidence of detectable urinary dilatation in utero is 1 per 100
- Of these cases the order of significant uropathy is 20% (or 0.2% of all children)
Considerations
- Most confusion occurs when fetal ultrasouns shows mild unilateral hydronephrosis or pelviectasis and a diagnosis of posterior urethral valves is unlikely
- There is controversy as to when to perform a RUS on newborns, ranging from 24 hours to 72 hours post delivery. Most agree that it is ideal to wait more than 72 hours.
- This delay supposedly compensates for the physiologically dehydrated state of the neonate in the first 24 to 48 hours of life
- Use of prophylactic antibiotics is controversial but still widely practiced
Screening and Management Recommendations
Serious Conditions
A fetal ultrasound consistent with…
- · Severe bilateral hydronephrosis,
- · Bilateral hydroureteronephrosis,
- · Multicystic dysplastic kidney, or
- · Male fetal hydronephrosis with h/o oligohydramnios
…requires immediate action, including…
- · Pediatric Urology Consult
- · Begin Amox or Keflex prophylaxis (10-25 mg/kg PO qd of either)
- · Renal/bladder US same day
- · Chem 10 at 12 hours of life
- · VCUG (time of study based on Urology recommendation)
Mild Hydonephrosis or Renal Pelviectasis
A fetal ultrasound with mild hydronephrosis or renal pelviectasis allows 2 options:
Option A:
Begin Amox or Keflex prophylaxis (10-25 mg/kg PO qd of either)
Renal/bladder US within 48 hours
- If US is positive, Pediatric Urology consult
- If US is negative, repeat renal/bladder US in one week
Option B:
Begin Amox or Keflex prophylaxis (10-25 mg/kg PO qd of either)
Renal/bladder US in one week
- If US is positive, Pediatric Urology consult
- If US is negative, no further workup necessary
Gonzalez and Schimke, 2001
