What is the appropriate management for a newborn presenting with hematuria (blood in urine) and possible urinary tract infection (UTI)?

Management of Hematuria and Possible UTI in a Newborn

The appropriate management for a newborn with hematuria and possible UTI requires prompt urine collection via catheterization or suprapubic aspiration for urinalysis and culture, followed by empiric antibiotic therapy while awaiting culture results. 1

Diagnosis

Urine Collection

• Obtain urine specimen before administering antibiotics to ensure accurate culture results 1
• Collection method for newborns:
  • Catheterization or suprapubic aspiration (SPA) are the only acceptable methods 1, 2
  • Bag specimens have unacceptably high false-positive rates and should not be used for culture 2

Diagnostic Criteria

• Definitive UTI diagnosis requires:
  • Pyuria and ≥50,000 CFU/mL of a single uropathogen, or
  • Pure growth of 250,000 CFUs/mL with urinalysis showing bacteriuria or pyuria 1
• Both abnormal urinalysis and positive urine culture are needed to confirm UTI 1

Initial Treatment

Empiric Antibiotic Therapy

For newborns 0-7 days:

• Ampicillin IV/IM (150 mg/kg/day divided every 8h) PLUS
• Gentamicin IV/IM (4 mg/kg/dose every 24h) or Ceftazidime IV/IM (150 mg/kg/day divided every 8h) 1

For newborns 8-21 days:

• Ampicillin IV/IM (150 mg/kg/day divided every 8h) PLUS
• Ceftazidime IV/IM (150 mg/kg/day divided every 8h) or Gentamicin IV/IM (4 mg/kg/dose every 24h) 1

For infants 22-60 days:

• Ceftriaxone IV/IM (50 mg/kg/dose every 24h) 1

Treatment Duration

• 7-14 days of antibiotic therapy is recommended 1
• Parenteral therapy should be used initially in newborns 1
• Can switch to oral therapy once clinical improvement is seen (usually within 24-48 hours) 1

Imaging Studies

Initial Imaging

• Renal and bladder ultrasound (RBUS) should be performed after the first febrile UTI 1, 2
• Should be performed even if prenatal ultrasound was normal 2
• Timing: Can be performed during acute infection or within 6 weeks 1, 2

Additional Imaging

• Voiding cystourethrography (VCUG):
  • Recommended for newborns with UTI, especially males 2
  • Higher yield in newborns due to increased incidence of urinary anomalies 3
  • Can detect vesicoureteral reflux (VUR) and posterior urethral valves even when ultrasound is normal 2
• DMSA renal scan:
  • Not routinely recommended in newborns with first UTI who respond well to treatment 2
  • May be considered later to evaluate for renal scarring if clinically indicated 2

Special Considerations

Risk Factors in Newborns

• Newborns have higher incidence of congenital anomalies of kidney and urinary tract 3
• Male predominance in the first 2 months of life (unlike older children) 2
• Concomitant bacteremia with UTI is common (4-36.4%) 2
• Presentation may be nonspecific:
  • May present with jaundice alone 3
  • May have low-grade or no fever 3
  • May present with symptoms similar to neonatal sepsis 4

Follow-up

• Clinical improvement should be seen within 48-72 hours of appropriate therapy 1
• If symptoms persist despite appropriate antibiotics, reassess treatment and consider additional imaging 1
• Long-term follow-up is essential to:
  • Identify predisposing congenital abnormalities
  • Monitor for scarred kidneys
  • Diagnose and treat recurrences early 4
• Instruct parents to seek prompt medical evaluation (within 48 hours) for future febrile illnesses 1

Antibiotic Considerations

• Adjust therapy based on culture and sensitivity results 1
• For ESBL-producing organisms (like some Klebsiella):
  • Carbapenems such as meropenem (60 mg/kg/day divided every 8 hours) are recommended 1
  • Standard cephalosporins are ineffective against ESBL producers 1
• Avoid nitrofurantoin in infants <4 months due to risk of hemolytic anemia 1

By following this approach, you can effectively diagnose and treat UTI in a newborn with hematuria while identifying any underlying anatomical abnormalities that may require further management.