Most newborn jaundice is treated with phototherapy, a safe light-based treatment that helps your baby’s body break down excess bilirubin. About 60% of full-term newborns develop some visible yellowing in their first week, and the vast majority resolve with feeding support, monitoring, or a short course of light therapy. The specific treatment depends on your baby’s bilirubin level, age in hours, gestational age, and whether any risk factors are present.
Why Newborns Get Jaundice
Newborns produce bilirubin faster than they can clear it. Bilirubin is a yellow pigment created when red blood cells break down, and babies are born with a high volume of red blood cells that have a shorter lifespan than adult cells. Their livers are also immature and slower at processing bilirubin for removal. The result is a temporary buildup that turns the skin and whites of the eyes yellow.
Visible yellowing typically appears when bilirubin rises above about 2 mg/dL. A normal adult level is 0.1 to 1.2 mg/dL, so even mild newborn jaundice represents a significant elevation. In most babies, levels peak around day three to five and then drop on their own. But when bilirubin climbs too high or rises too fast, treatment prevents it from reaching levels that could damage the brain.
Frequent Feeding Is the First Step
For mild jaundice, the most important thing you can do is feed your baby frequently. Bilirubin leaves the body through stool, and more feedings mean more bowel movements. When a newborn isn’t getting enough milk, bilirubin gets reabsorbed from the intestines back into the bloodstream, pushing levels higher.
This is why “breastfeeding jaundice” is common in the first week, when milk supply is still being established. The CDC notes that more frequent breastfeeding improves both caloric intake and hydration, directly helping reduce bilirubin. Aim for 8 to 12 feedings per day in those early days. If your baby is too sleepy to latch well or isn’t producing enough wet and dirty diapers, your pediatrician may recommend supplementing with expressed breast milk or formula to keep things moving through the gut.
How Phototherapy Works
Phototherapy is the standard treatment when bilirubin levels cross a specific threshold for your baby’s age and risk profile. It uses blue-green light in the 460 to 490 nanometer range, which penetrates the skin and converts bilirubin molecules into water-soluble forms the body can excrete without needing the liver to process them first. The converted bilirubin passes out through urine and stool.
In the hospital, phototherapy typically involves placing your baby under overhead LED lights while wearing only a diaper and protective eye covers. The goal is to expose as much skin as possible. Your baby stays under the lights continuously, with breaks only for feeding. Bilirubin levels are rechecked every 4 to 12 hours during treatment to track whether levels are dropping.
Most babies need phototherapy for one to two days. The lights don’t hurt, though your baby may be fussy from the eye covers or from being undressed. Loose, frequent stools during phototherapy are normal and actually a sign the treatment is working, since that’s how the broken-down bilirubin leaves the body.
When Home Phototherapy Is an Option
Some babies qualify for phototherapy at home using a fiber-optic blanket or pad (often called a BiliBlanket) that wraps around the baby or sits underneath them. Home phototherapy works best for healthy, full-term infants who are feeding well, voiding and stooling normally, and whose bilirubin levels fall in a moderate range rather than near the hospital treatment threshold.
For example, a well baby born at 38 weeks or later with no risk factors might be a candidate for home phototherapy if their bilirubin is around 12 to 13 mg/dL at 48 hours of age, or 14.5 to 15.5 mg/dL at 72 hours. Babies born between 35 and 37 weeks have lower thresholds: roughly 10 to 11 mg/dL at 48 hours.
Home phototherapy is not appropriate when jaundice appears within the first 24 hours of life, when the baby is premature (under 35 weeks), or when risk factors are present. These risk factors include immune-related blood type incompatibility between parent and baby, G6PD deficiency (an inherited enzyme condition), sepsis, significant lethargy, or low albumin levels.
What Triggers Hospital-Level Treatment
The decision to start phototherapy in the hospital is based on standardized charts that plot bilirubin levels against the baby’s age in hours and gestational age. The American Academy of Pediatrics published updated guidelines in 2022 with separate threshold curves depending on whether a baby has additional risk factors for bilirubin-related brain injury.
A baby born at 38 weeks with no risk factors has a higher treatment threshold than one born at 35 weeks, and a baby with risk factors like blood type incompatibility or G6PD deficiency has a lower threshold at any gestational age. Your pediatrician plots your baby’s specific bilirubin result on the appropriate chart and compares it to the treatment line. If the level is at or above the line, phototherapy starts. If it’s below but rising quickly, closer monitoring or early treatment may be recommended.
Exchange Transfusion for Severe Cases
When bilirubin reaches dangerously high levels despite intensive phototherapy, an exchange transfusion may be needed. This is rare and considered a medical emergency. The procedure gradually replaces the baby’s blood with donor blood, physically removing the excess bilirubin from the bloodstream. A double-volume exchange reduces bilirubin by about 50% immediately, though levels typically rebound to roughly two-thirds of the pre-exchange level within four hours, which is why intensive phototherapy continues afterward.
Exchange transfusion thresholds vary by the baby’s age and risk level. For a lower-risk full-term infant, the threshold at 24 hours is around 18.7 mg/dL, rising to about 25 mg/dL by 96 hours. Higher-risk infants have significantly lower thresholds. Any baby showing signs of acute bilirubin encephalopathy, such as a high-pitched cry, arching of the back, or extreme sleepiness, may need an immediate exchange regardless of the exact number.
When Blood Type Incompatibility Is the Cause
Some jaundice is driven by immune-related destruction of the baby’s red blood cells, most commonly when the mother and baby have incompatible blood types (Rh or ABO incompatibility). In these cases, the mother’s antibodies cross the placenta and attack the baby’s red blood cells, releasing bilirubin much faster than normal.
These babies often develop jaundice within the first 24 hours and their levels can rise rapidly. Treatment includes intensive phototherapy started immediately, and in some cases an infusion of immunoglobulin is given to slow the antibody-driven destruction of red blood cells. This type of jaundice requires closer monitoring and lower treatment thresholds because the bilirubin rise can be steep and unpredictable.
Why Bilirubin Levels Are Checked Carefully
Hospitals screen bilirubin before discharge using either a blood draw or a handheld skin sensor placed on the baby’s forehead or chest. The skin sensor is painless and gives a quick reading, but it’s a screening tool rather than a definitive measurement. It tends to read higher than the actual blood level, which means it may flag babies for a blood test who turn out to be fine. Research in one study found the skin reading overestimated the true level by 2 mg/dL or more in about 65% of measurements. This is by design: it’s meant to catch high levels rather than miss them.
If the skin reading is elevated, a blood sample confirms the actual bilirubin level. Treatment decisions are always based on the blood test, not the skin sensor alone.
Follow-Up After Discharge
The timing of your baby’s first follow-up visit after leaving the hospital depends on where their bilirubin level sits relative to the treatment threshold. A baby whose level is well below the threshold and trending downward may not need a recheck for two to three days. A baby whose level is closer to the treatment line may need a recheck within 24 hours.
The 2022 AAP guidelines recommend that if a family cannot reliably make a follow-up appointment, the hospital should consider delaying discharge until 72 to 96 hours of age. This gives bilirubin time to peak and begin declining while the baby is still being monitored. If your baby was discharged early (before 48 hours), the follow-up visit is especially important because bilirubin may not have peaked yet.
The Risk of Untreated Severe Jaundice
The reason jaundice is monitored so carefully is kernicterus, a form of permanent brain damage caused by extremely high bilirubin. At levels around 25 mg/dL or higher, bilirubin can cross into the brain and damage areas that control movement, hearing, and eye coordination. Kernicterus can cause cerebral palsy, hearing loss, and intellectual disability.
Kernicterus is preventable with timely treatment, and it is extremely rare in countries with routine newborn screening. The vast majority of jaundiced babies never come close to dangerous levels. But it’s the reason hospitals check bilirubin before discharge, schedule early follow-up visits, and take rising levels seriously even in babies who otherwise look healthy.