Jaundice in newborns, which produces a yellow colour to
the skin and eyes, is caused by a buildup of
bilirubin in the blood (hyperbilirubinemia). In the
womb, a fetus obtains nutrients and eliminates by-products, such as bilirubin,
through the umbilical cord. After birth, the baby's organs take over these
jobs.
Newborns may develop jaundice from a buildup of bilirubin for
slightly different reasons.
Physiologic jaundice
Physiologic jaundice develops between 1 and 5 days after birth
because babies' organs are not yet able to eliminate excess bilirubin
effectively. Whether jaundice is noticeable depends in part on how high blood
bilirubin levels reach.
If noticeable, the yellowing of the skin and eyes usually appears
about 24 hours after birth and increases until about the third or fourth day.
Most often, bilirubin levels in the blood then gradually lower and the
yellowing fades or disappears in about a week without causing problems.
Premature babies, whose organs often are not fully developed, are
less able to eliminate bilirubin effectively and are more likely than full-term
babies to develop noticeable yellowing related to jaundice.
Breast-feeding jaundice
Breast-feeding jaundice is caused by mild dehydration,
which prolongs and intensifies physiologic jaundice. Dehydration contributes to
jaundice because it makes removing bilirubin from the body even harder for
babies' immature systems. Breast-feeding jaundice can occur when a baby does
not get enough fluids, most often because feedings are spaced too far apart.
Mothers usually produce about
15 mL (0.5 fl oz) to 22 mL (0.75 fl oz) of
colostrum at each feeding in the days before breast
milk comes in. Most babies need about
30 mL (1 fl oz) to
45 mL (1.5 fl oz) of fluid every
4 hours. Breast-fed babies who are fed every 4 or more hours (as are many
formula-fed babies) will gradually become dehydrated, and bilirubin levels in
the blood will rise or remain elevated.
A baby is less likely to develop significant breast-feeding
jaundice when fed frequently.1 The Canadian Paediatric Society recommends that mothers breast-feed 8 to 12 times every 24
hours. If jaundice is noticeable, it may help to feed your baby every 2 hours.
Frequent feedings increase the production of colostrum (and breast
milk, once it comes in), which ensures that the baby gets enough nutrition and
fluid to get rid of the extra bilirubin. Supplementing breast milk with water
or sugar water does not help lower the bilirubin levels in these babies.
Breast milk jaundice
After physiological and/or breast-feeding jaundice has resolved
(usually by 5 to 7 days), bilirubin levels may rise again during the second
week (10 to 14 days) in breast-fed babies. This type of jaundice is likely
related to how certain components of breast milk affect bilirubin elimination
in the infant.
Usually, breast milk jaundice gradually decreases, although most
babies often have mild jaundice throughout the duration of breast-feeding.
Bilirubin levels rarely rise to harmful levels, and most often health
professionals recommend continuing with exclusive breast-feeding. Sometimes a
bilirubin blood test is done to assure that the bilirubin level is in an
acceptable range.
Most of the time bilirubin does not cause problems, but occasionally
the amount of bilirubin in a newborn's blood rises to a level that could be
harmful. When this happens, the yellowing of a baby's skin and eyes (jaundice)
becomes more pronounced and he or she may become irritable and sluggish and have
a high-pitched cry. Parents should report these symptoms to their health
professional right away.
Rarely, excessive amounts of bilirubin build up in the blood and lead
to brain damage (kernicterus), which can result in hearing loss, mental
retardation, and behaviour problems.