From the Guidelines
Red urine in a newborn is most commonly due to "brick dust" urine, which is caused by uric acid crystals and is normal in the first few days of life, but it can also indicate hematuria, which may require medical attention. This condition typically resolves on its own with adequate hydration 1. However, if the red color persists beyond 3-4 days, is bright red rather than pink or rust-colored, or is accompanied by other symptoms like poor feeding, lethargy, or fever, parents should contact their pediatrician immediately 1.
Key Considerations
- Parents should ensure their newborn is feeding well and having enough wet diapers (at least 6-8 per day after the first few days) 1.
- In rare cases, red urine could indicate a urinary tract infection, kidney problems, or bleeding disorders that require treatment 1.
- The pediatrician may need to collect a urine sample to determine the cause, and imaging evaluation may be necessary depending on the clinical scenario, with ultrasound being the best modality to display the anatomy, size, and position of the kidneys 1.
Recommendations
- If the red color persists or is accompanied by other symptoms, parents should seek medical attention immediately.
- A thorough evaluation of the urine, including a urine culture and assessment for hypercalciuria, may be indicated 1.
- Imaging evaluation, such as ultrasound, may be necessary to identify the cause of hematuria and assess the size of the kidneys 1.
From the Research
Causes of Red Urine in Newborns
- Hematuria, which is the presence of blood in the urine, can cause red urine in newborns 2, 3
- Urinary tract infections (UTIs) can also cause hematuria in newborns, although the urinalysis may be negative in some cases 4, 5
- Other causes of hematuria in newborns include renal vein thrombosis, renal artery thrombosis, renal cortical necrosis, and tubular necrosis 2
- Bilirubin or excessive ingestion of carotene or other food pigments can cause discoloration of urine similar to that seen in hematuria 2
- The "red diaper syndrome" caused by Serratia marcescens colonization of the gastrointestinal tract can also cause red urine in newborns 2
Diagnosis and Evaluation
- Urine culture is the key instrument for the diagnosis of UTIs in newborns 4
- Renal imaging should be performed in newborns with UTI to check for congenital anomalies of the kidney and urinary tract 5
- A thorough history and physical examination should be performed to determine potential causes of hematuria and assess risk factors for malignancy 6
- Laboratory tests and imaging of the urinary tract may be necessary to rule out intrinsic renal disease and other causes of hematuria 6
Clinical Manifestations
- Jaundice in the absence of any other symptoms or signs may be the only clinical manifestation of UTI in neonates 5
- Half of neonates with UTI may have only low-grade fever or no fever 5
- Hematuria in newborns may be transient, but may require evaluation, investigation, and intervention in a timely manner 3