What Is Phototherapy?
Phototherapy is a treatment that uses special blue light to help lower bilirubin levels in a newborn baby's blood.
Bilirubin is a yellow substance produced when the body breaks down old red blood cells.
When bilirubin builds up, it can cause jaundice, which makes a baby's skin and the whites of their eyes appear yellow.
Jaundice is common in newborns, particularly premature babies, because their livers are still developing the ability to process bilirubin efficiently.
Phototherapy is a common, effective treatment that helps your baby's body remove excess bilirubin.
How Does Phototherapy Work?
Phototherapy uses a special type of blue light that changes bilirubin in the skin into forms the body can eliminate more easily.
These forms of bilirubin can then leave the body through urine and stool.
The treatment does not hurt your baby, and the light does not feel hot like a traditional heat lamp.
You may hear the healthcare team refer to phototherapy as bili lights.
Why Does My Baby Need Phototherapy?
Your baby may need phototherapy if their bilirubin level rises above the treatment threshold appropriate for their age and medical condition.
Premature babies are more likely to develop jaundice because:
Their livers are still immature.
They may break down red blood cells more rapidly.
Their bodies may take longer to eliminate bilirubin.
Feeding difficulties can sometimes contribute to bilirubin buildup.
The healthcare team uses your baby's gestational age, age after birth, bilirubin level, and other risk factors to determine whether treatment is necessary.
What Does Phototherapy Look Like?
During phototherapy, your baby may be placed under a special blue light or on a light-emitting pad or blanket.
Depending on the equipment, your baby may:
Wear only a diaper to expose more skin to the light
Have protective eye coverings
Lie in an incubator or open warmer
Receive treatment from one or more light sources
Some babies receive phototherapy using a special lighted blanket or pad placed against their skin.
The type of equipment depends on your baby's needs and the NICU's available devices.
Why Does My Baby Wear Eye Protection?
Babies receiving overhead phototherapy usually wear soft protective eye coverings.
These help protect their eyes from direct exposure to the treatment light.
The healthcare team makes sure the coverings fit appropriately and checks your baby's eyes and skin during care.
Eye protection may not be necessary with some types of phototherapy blankets when the light is directed away from the eyes.
Can I Still Hold or Feed My Baby During Phototherapy?
Often, yes.
Whether your baby can take breaks from phototherapy depends on their bilirubin level, the intensity of treatment needed, and their overall medical condition.
Some babies can be removed briefly for feeding or holding.
Others need more continuous exposure to the lights.
If your baby is receiving intensive phototherapy, the healthcare team may recommend limiting interruptions until bilirubin levels improve.
Ask your baby's nurse when holding, feeding, or skin-to-skin care can be safely incorporated into treatment.
How Does the NICU Know if Phototherapy Is Working?
The healthcare team checks your baby's bilirubin level through blood testing.
These measurements help determine whether bilirubin is decreasing with treatment.
The team may also monitor:
Body temperature
Feeding tolerance
Hydration
Urine and stool output
Overall clinical condition
Your baby's skin color alone is not a reliable way to determine whether the bilirubin level has improved.
How Long Will My Baby Need Phototherapy?
The length of treatment varies.
Some babies need phototherapy for less than a day, while others require several days or additional treatment periods.
Treatment duration depends on:
How high the bilirubin level is
How quickly the level decreases
Your baby's gestational age
The underlying cause of jaundice
Whether bilirubin rises again after treatment
The healthcare team will explain when treatment can safely be discontinued.
Can Bilirubin Increase Again After Phototherapy?
Yes.
Sometimes bilirubin levels rise again after phototherapy is stopped. This is called rebound hyperbilirubinemia.
The NICU team may repeat a bilirubin test after treatment, particularly if your baby is premature or has other risk factors.
Some babies need another period of phototherapy if their bilirubin rises enough to require treatment again.
This does not necessarily mean the original treatment was unsuccessful.
Is Phototherapy Safe?
Phototherapy has been used for many years and is generally considered a safe and effective treatment for newborn jaundice.
The NICU team monitors babies for possible effects such as:
Changes in body temperature
Increased fluid loss
Loose stools
Temporary skin changes
The healthcare team also monitors hydration and adjusts care when necessary.
The benefits of appropriately prescribed phototherapy generally outweigh its potential risks.
Why Is Treating High Bilirubin Important?
Very high levels of bilirubin can be harmful, particularly if bilirubin affects the brain.
Severe bilirubin-related brain injury is uncommon, especially when elevated levels are recognized and treated promptly.
Phototherapy helps reduce bilirubin levels and lowers the risk of serious complications.
Premature babies may require treatment at lower bilirubin levels than full-term babies because they can be more vulnerable to bilirubin-related complications.
What Can Parents Ask?
If your baby is receiving phototherapy, consider asking:
What is my baby's current bilirubin level?
Is the bilirubin level improving?
How often will blood tests be needed?
Can I hold or feed my baby during treatment?
How long might phototherapy continue?
Will bilirubin be checked again after the lights are stopped?
What Should Parents Know?
Phototherapy is a common treatment for newborn jaundice.
It uses special blue light to help your baby's body eliminate excess bilirubin.
Needing phototherapy does not necessarily mean your baby has a serious medical problem.
Many premature and full-term babies require this treatment as their bodies adjust after birth.
Your baby's NICU team will monitor bilirubin levels and determine when the lights can safely be discontinued.
