Phototherapy (Jaundice)

Phototherapy for jaundice is a treatment that uses special blue-spectrum light to break down excess bilirubin (a yellow pigment produced when red blood cells are broken down) in a newborn's blood.

When a baby's liver is not yet mature enough to clear bilirubin on its own, the pigment builds up in the skin and eyes, turning them yellow — a condition called neonatal jaundice (newborn yellowing). During phototherapy, the baby lies under a lamp or on a light-emitting blanket. The light energy changes the shape of bilirubin molecules so the body can flush them out through urine and stool without the liver having to process them fully.

Phototherapy is used when a newborn's bilirubin level rises high enough to pose a risk to the brain. The paediatrician (children's doctor) decides based on the baby's age in hours, blood bilirubin test results, and any additional risk factors.

• Neonatal jaundice (newborn yellowing) where bilirubin reaches a treatment threshold
• Jaundice appearing within the first 24 hours of life, which is considered high-risk
• Jaundice in premature babies (born before 37 weeks), who are more vulnerable to high bilirubin
• Haemolytic jaundice (yellowing caused by blood group incompatibility between mother and baby, such as Rhesus or ABO incompatibility)
• Jaundice in newborns with bruising from a difficult delivery, which releases extra bilirubin
• Raised bilirubin after early hospital discharge, caught at a follow-up check

Phototherapy is not suitable in every situation. Doctors will consider other options or add treatments when:

• Bilirubin is rising so rapidly that phototherapy alone cannot keep up — a blood exchange transfusion (replacing the baby's blood) may be needed
• The jaundice is caused by a blockage in the bile ducts (cholestatic jaundice), where light therapy does not address the root cause
• The baby has a rare metabolic condition called congenital erythropoietic porphyria, where light can damage the skin

Phototherapy is generally considered a very safe treatment for newborns, and serious complications are uncommon. The recognised risks are mostly mild and temporary:

• Loose, frequent stools — bilirubin is excreted through the gut, and this is expected and harmless
• Dehydration — increased fluid loss through the skin under the lights, so feeding is monitored closely
• Skin rash — a temporary, harmless rash may appear on the skin exposed to the light
• Temperature instability — babies can become slightly too warm or too cool under the lamp, so temperature is checked regularly
• Eye discomfort — the baby's eyes are covered with small shields during treatment to protect them from the bright light
• Disruption to feeding and bonding — the baby spends time away from the parent; most hospitals encourage short breaks for breastfeeding
• Bronze baby syndrome — a rare, harmless darkening of the skin and urine that can occur in babies who also have cholestatic (bile duct-related) jaundice; it fades after treatment ends

Because phototherapy is most often started urgently in a hospital after a bilirubin test result, there is usually little advance preparation for the family. However, the care team will take several steps before and during the treatment.

Before phototherapy begins, the medical team typically:

• Checks the baby's bilirubin level with a blood test or a non-invasive skin probe (transcutaneous bilirubinometer)
• Reviews the baby's gestational age (how many weeks pregnant the mother was), birth weight, and any known risk factors such as blood group incompatibility
• Removes the baby's clothing and nappy so the maximum skin surface is exposed to the light
• Places small, soft eye shields (eye patches) on the baby to protect the eyes
• Ensures the baby is well-fed before starting, since good hydration helps clear bilirubin

During the treatment itself, the following usually happens:

• 1. The baby is placed in an open cot or incubator (a clear enclosed warming unit) under the phototherapy lamp, or on a biliblanket (a fibre-optic mat that emits light from below).
• 2. The lamp is positioned at the recommended distance from the baby's skin, as set by the equipment guidelines.
• 3. The baby is repositioned regularly — usually alternating front and back — to expose as much skin as possible.
• 4. Feeding continues during therapy; in most hospitals, the baby is briefly removed from the light for breastfeeding or bottle feeding.
• 5. The baby's temperature, hydration, and skin colour are checked at regular intervals by the nursing team.
• 6. Bilirubin levels are retested periodically with blood samples to track progress and decide when treatment can stop.

Once the bilirubin level has fallen to a safe range and remained stable, the phototherapy lamp is turned off and the eye shields are removed. Most babies recover well and can be with their parents normally. The care team will continue to monitor the baby for a period to make sure bilirubin does not rise again — a phenomenon called rebound hyperbilirubinaemia (a bounce-back rise in bilirubin after treatment stops), which is more common in some babies than others.

• Bilirubin is usually rechecked with a blood test some hours after the light is switched off, before the baby is discharged
• Frequent feeding — breast milk or formula — is encouraged to help flush out remaining bilirubin through the stools
• A follow-up appointment is usually arranged within one to two days of going home so the doctor can recheck bilirubin with a skin probe or blood test
• Parents are advised on what signs of worsening jaundice to watch for at home, such as deepening yellow colour, poor feeding, or unusual sleepiness
• If jaundice was caused by an underlying condition such as a blood group incompatibility, the paediatrician will arrange further investigation and monitoring
• In most cases, no special wound care, medication, or long-term restriction is needed after standard phototherapy
• Breastfeeding is usually strongly encouraged throughout recovery, as it supports overall newborn health