What is bilirubin?
Bilirubin is a yellow pigment made when red blood cells are broken down — something every body does all the time. The liver normally clears it. Newborns make more bilirubin than adults (they're born with extra red blood cells), and their livers take a few days to get up to speed. While supply outpaces clearing, bilirubin builds up and tints the skin and eyes yellow. That's jaundice.
Usually, it's a normal part of the first week
Jaundice shows up in more than half of healthy newborns — typically appearing on day 2–4, peaking around day 3–5, and fading over one to two weeks. Feeding well is the main way babies clear bilirubin, so frequent effective feeds genuinely help.
Why it still gets checked
Very high bilirubin can, rarely, injure a baby's brain — and that harm is preventable with monitoring and simple treatment. That's why every baby is checked before leaving the hospital or birth centre: a painless skin meter or a small blood test, plotted on a chart that accounts for your baby's age in hours and how early they were born. It's a routine safety net, not a cause for alarm.
Get medical help promptly if…
- Jaundice appears in the first 24 hours of life
- The yellow is deepening or spreading to the legs, palms, or soles
- Baby is hard to wake, unusually floppy, or has a high-pitched cry
- Feeding poorly, or fewer wet diapers than expected
- Stools are pale or chalky, or urine is dark
- Jaundice is still obvious beyond 2–3 weeks
- Any fever in a newborn — that's urgent on its own
Contact your midwife or doctor, call your nurse line (8-1-1 in BC), or go to emergency care. Trust your instincts — checking is always okay.
How it's treated
When bilirubin crosses the treatment threshold for your baby's age, the usual treatment is phototherapy — special blue light that converts bilirubin in the skin into a form the body can flush out. It's safe, painless, and often only needed for a day or two. Feeding support goes alongside it. In rare, severe cases, an exchange transfusion is used.
Where this comes from
- Canadian Paediatric Society — Guidelines for the detection, management and prevention of hyperbilirubinemia in newborns (≥35 weeks)
- Caring for Kids (CPS) — Jaundice in newborns
- American Academy of Pediatrics — 2022 clinical practice guideline on hyperbilirubinemia