Bilirubin (bill-uh-ROO-bin) is produced by the normal breakdown of red blood cells. Normally, it passes through the liver, which releases it into the intestines as bile (a liquid that helps with digestion).
Jaundice happens when bilirubin builds up faster than a newborn's liver can break it down and pass it from the body. Here are some reasons why:
Newborns make more bilirubin than adults do since they have more turnover of red blood cells.
A newborn baby's still-developing liver might not be able to remove enough bilirubin from the blood.
A baby's intestines absorb bilirubin that would normally leave the body in the stool (poop).
High levels of bilirubin — usually above 25 mg — can cause deafness, cerebral palsy, or other forms of brain damage in some babies. In less common cases, jaundice may be a sign of of another condition, such as an infection or a thyroid problem.
Doctors recommend that all infants be checked for jaundice within a few days of birth.
Types of Jaundice
The most common types of jaundice are:
Physiological (normal) jaundice: Most newborns have this mild jaundice because their liver is still maturing. It often appears when a baby 2 to 4 days old and disappears by 1 to 2 weeks of age.
Jaundice of prematurity: This is common in premature babies since their bodies are even less ready to excrete bilirubin effectively. To avoid complications, they'll be treated even when their bilirubin levels are lower than those of full-term babies with normal jaundice.
Breastfeeding jaundice: Jaundice can happen when breastfeeding babies don't get enough breast milk due to difficulty with breastfeeding or because the mother's milk isn't in yet. This is not caused by a problem with the breast milk itself, but by the baby not getting enough of it. If a baby has this type of jaundice, it's important to involve a lactation (breastfeeding) consultant.
Breast milk jaundice: In 1% to 2% of breastfed babies, jaundice is caused by substances in breast milk that can make the bilirubin level rise. These can prevent the excretion of bilirubin through the intestines. It starts after the first 3 to 5 days and slowly improves over 3 to 12 weeks.
Blood group incompatibility (Rh or ABO problems): If a mother and baby have different blood types, the mother's body might produce antibodies that destroy the infant's red blood cells. This creates a sudden buildup of bilirubin in the baby's blood. Incompatibility jaundice can begin as early as the first day of life. Rh problems once caused the most severe form of jaundice, but now can be prevented by giving the mother Rh immune-globulin injections.
Jaundice usually appears around the second or third day of life. A jaundiced baby's skin usually will appear yellow first on the face, then the chest and stomach, and finally, the legs. It can also make the whites of a baby's eyes look yellow.
Most newborns now go home from the hospital 1 or 2 days after birth, so it's important for their doctors to check them for jaundice 1 to 2 days later.
Parents also should watch their baby for jaundice. Jaundice can be hard to see, especially in babies with dark skin. If you're unsure, gently press the skin on your baby's nose or forehead — if jaundice is present, the skin will appear yellow when you lift your finger.
When to Call the Doctor
Call your doctor know if you think your baby might have jaundice. The doctor might take a small blood sample to measure your baby's bilirubin level. Some offices use a light meter to get an approximate measurement, and then if it's high, take a blood sample.
Also call your doctor immediately if:
your baby has jaundice during the first 24 hours of life
the jaundice is spreading or getting darker or more intense
your baby has a fever over 100°F (37.8°C) rectally
your baby starts to look or act sick
your baby is not feeding well
you feel your baby is sleepier than usual
It is difficult to tell how significant jaundice is just by looking at a baby, so any baby with yellow eyes or skin should be checked by a doctor.
Most cases of newborn jaundice don't require treatment. Mild or moderate jaundice will go away after 1 or 2 weeks as the baby's body becomes able to get rid of the excess bilirubin on its own.
For high levels of jaundice, phototherapy — treatment with a special light that helps rid the body of the bilirubin — may be used.
More frequent feedings of breast milk or supplementing with formula to help infants pass the bilirubin in their stools also may be recommended. In rare cases, a blood transfusion may be done.
In some cases, the doctor may ask a mother to temporarily stop breastfeeding. If this happens, pump often to keep producing breast milk, then start nursing again once the jaundice has cleared.