Bilirubin Metabolism & Neonatal Jaundice

An unborn baby has extra red blood cells to carry the oxygen it receives from its mother through the placenta. After birth, the newborn is breathing oxygen and the extra blood cells are no longer needed. The infant's liver destroys the red blood cells. A by-product of that process is bilirubin. Bilirubin is eliminated, or metabolized, through stools and the skin, which causes yellow coloring, or jaundice. Mild jaundice may protect newborns from free radicals, according to the National Academy of Sciences.

History

Due to a high incidence of Rh hemolytic disease in the 1950s, treatment of neonatal jaundice was aggressive. Such treatment continued through the 1970s although the development of Rhogam, a vaccine for mothers with an Rh negative blood type, dramatically reduced the incidence of serious blood incompatibilities. Phototherapy treatment was developed when a nursery nurse noticed that babies placed near the window were less yellow than other babies.

Significance

Neonatal jaundice, also called kernicterus, occurs within the first 24 hours after birth, or that is characterized by extremely high (over 30mg/dL) total serum bilirubin (TBS), is considered high risk. Infants in that category are at risk of brain damage, liver disease, and if untreated, death. Blood transfusions may be necessary to save those babies. Only one in 10,000 infants are high risk.

Types

In a normal term infant, levels of bilirubin peak at less than 12 mg/dL in the first three to five days of life. TBS levels below 20 mg/dL are considered low risk. Moderately higher than normal bilirubin levels, called hyperbilirubinemia, are associated with mothers who have O positive blood types, and may have less serious ABO incompatibilities. Premature infants, who have immature livers that cannot adequately process the destruction of extra red blood cells, are also at risk for hyperbilirubinemia.

Identification

The rate of rise of total serum bilirubin in the first 24 to 48 hours is a predictor of serious jaundice, so babies that look yellow right after birth should receive medical attention. Physiological (normal) newborn jaundice occurs on the third to fourth day of life, and is noticeable first in the face and the whites of the eyes. Jaundice that spreads below the belly button to the hips and legs may be indicative of higher bilirubin levels. A jaundiced newborn who becomes lethargic and does not feed well should be evaluated by healthcare professionals.

Prevention/Solution

Unlike commercial infant formulas, breastmilk binds with bilirubin and carries it out through the digestive tract, so mothers should begin nursing early and breastfeed as often as possible to prevent jaundice.
The skin is an organ of elimination. Sunlight, either direct or indirect through a window, helps newborn skin eliminate jaundice more quickly. Expose as much naked skin as possible to the light. Use common sense to avoid extremes of temperature or sunburn.
Artificial light is effective if it is close enough. The baby's eyes must be shaded or covered to prevent harm. Home health product suppliers can provide a "biliblanket" that glows, for wrapping jaundiced infants.
Elimination of bilirubin can also be helped by feeding extra fluids, especially if a baby is being treated by phototherapy, or artificial lights, in the hospital or at home.