Why Newborns Get Jaundice

Jaundice in newborns (neonatal jaundice) is remarkably common, affecting a significant proportion of full-term infants and an even larger proportion of premature babies. In most cases, the cause is physiological — the newborn's liver is simply not yet mature enough to efficiently process bilirubin, the yellow pigment released when red blood cells break down. Because newborns have a higher rate of red blood cell turnover than adults, bilirubin accumulates quickly.

While mild physiological jaundice typically resolves on its own within the first two weeks of life, higher bilirubin levels require treatment to prevent a rare but serious complication called kernicterus — brain damage caused by bilirubin depositing in brain tissue.

What Is Phototherapy?

Phototherapy (light therapy) is the first-line, most widely used treatment for neonatal jaundice. It works by exposing the baby's skin to specific wavelengths of light — typically blue-green light in the range of 460–490 nanometers — which converts bilirubin in the skin into water-soluble forms that can be excreted in urine and stool without needing to be processed by the liver.

This photochemical conversion happens through two main processes:

  • Photoisomerization: Bilirubin molecules are rearranged into a more soluble form (lumirubin) that can be excreted directly.
  • Photo-oxidation: Bilirubin is broken down into smaller, colorless compounds.

Types of Phototherapy

Conventional Phototherapy

The baby lies under fluorescent or LED lamps in the NICU or nursery. Eyes are protected with soft patches to shield them from the light. The baby is repositioned periodically to maximize skin exposure. Feeding continues normally and is actually encouraged, as adequate hydration supports bilirubin excretion.

Fibre-Optic (Bili-Blanket) Phototherapy

A fibre-optic blanket or pad delivers light directly to the baby's back. This method can sometimes be used at home for mild jaundice under medical supervision, allowing parents to hold and breastfeed their baby normally during treatment.

Intensive Phototherapy

When bilirubin levels are very high or rising quickly, high-irradiance phototherapy using multiple light sources simultaneously is used. This approach delivers a much greater dose of light to bring bilirubin levels down rapidly.

What to Expect During Treatment

Parents new to phototherapy often have concerns. Here is what the process generally involves:

  • The baby will have protective eye shields in place at all times under the lights.
  • The baby's temperature, hydration, and bilirubin levels are monitored regularly (typically with blood tests every 4–12 hours).
  • Feeding — whether breastfeeding or formula — is actively encouraged and should not be stopped. Frequent feeding helps excrete bilirubin through the bowel.
  • The baby's skin may appear slightly bronzed during treatment ("bronze baby syndrome"), particularly if direct bilirubin is also elevated. This is generally harmless and resolves after treatment.
  • Treatment typically continues until bilirubin levels fall below a safe threshold for the baby's age and weight.

When Is Exchange Transfusion Needed?

In severe cases where bilirubin levels do not respond sufficiently to phototherapy, or where levels have reached a critical threshold, an exchange transfusion may be required. This procedure involves replacing a portion of the baby's blood with donor blood to rapidly reduce bilirubin levels. It is performed in specialized neonatal units and is now much less common thanks to early detection and effective phototherapy.

Monitoring After Treatment

After phototherapy is stopped, bilirubin levels are rechecked. A small rebound rise in bilirubin is normal within the first 24 hours after treatment ends. Most babies are discharged once their levels are stable and declining. Parents should watch for signs of worsening jaundice at home — particularly yellowing that spreads below the belly button, a baby who is unusually difficult to wake, or poor feeding — and seek prompt medical review if any of these occur.

Key Takeaways for Parents

  1. Phototherapy is safe, effective, and well-established for treating neonatal jaundice.
  2. Feeding frequently (8–12 times per day) supports treatment — do not restrict feeds.
  3. Bilirubin levels are monitored closely; treatment stops when levels are safely low.
  4. Most babies with jaundice treated with phototherapy have excellent outcomes.
  5. If you are concerned about your newborn's jaundice, always consult your midwife, pediatrician, or neonatologist.