Neonatal jaundice is the term used when a newborn has an excessive amount of bilirubin in the blood. Bilirubin is a yellowish-red pigment that is formed and released into the bloodstream when red blood cells are broken down. Jaundice comes from the French word
jaune, which means yellow; thus a jaundiced baby is one whose skin color appears yellow due to bilirubin.
Description
Normally, small amounts of bilirubin are found in everyone's blood. It is formed and released into the bloodstream when red blood cells are broken down. It is then carried to the liver where it is processed and eventually excreted from the body. When too much bilirubin is made, the excess is discarded into the bloodstream and deposited in tissues for temporary storage. In the neonate, however, there is more bilirubin than can be handled due to immature liver functioning and extra red blood cells that break down. Thus, the extra bilirubin remains in the tissues. Neonatal jaundice affects 60 percent of full-term infants and 80 percent of preterm infants in the first three days after birth.
Demographics
Infants of East Asian and Native American descent have higher levels of bilirubin than white infants, who in turn have higher bilirubin levels than infants of African descent. There is an enzyme, glucose-6-phosphate dehydrogenase (G6PD), deficiency that is more prevalent in infants of East Asian, Greek, and African descent which causes neonatal jaundice to appear at approximately the same time as physiological jaundice. Sickle cell anemia does not predispose newborn infants to jaundice.
Causes and symptoms
Typically, neonatal jaundice occurs in otherwise healthy infants for two reasons. First, infants have too many red blood cells and it is a natural process for the body to break down these excess red blood cells to form a large amount of bilirubin. It is this bilirubin that causes the skin to take on a yellowish color. Second, the newborn's liver is immature and cannot process bilirubin as quickly as the infant will be able to when older. This slow processing of bilirubin has nothing to do with liver disease. It merely means that the baby's liver is not as fully developed as it will be; thus, there is some delay in eliminating the bilirubin.
Breastfeeding is an important risk factor for hyperbilirubinemia in healthy infants and is related to inadequate maternal milk supply in the first few days, decreased caloric intake and delayed passage of meconium. Nonetheless, this is not a reason to give formula or stop breastfeeding. The breastfeeding mother just needs to nurse the baby more frequently and for longer periods of time to enhance the production of breastmilk. Other factors that cause neonatal jaundice are ABO incompatibility and Rh incompatibility. Both of these conditions result in a very fast breakdown of red blood cells. It is also possible for jaundice to appear in infants with physical defects in the organs that work to eliminate bilirubin from the body. An abnormal increase in red blood cells is frequently seen in infants who are large or small for their gestational age, as well as in trisomy syndromes, twin-to-twin transfusion syndrome, maternal-fetal transfusion, use of oxytocin in labor, Asian male babies, presence of bruising and cephalohematoma, and a family history of neonatal jaundice.
As the excess bilirubin builds up in the newborn, jaundice appears first in the face and upper body and progresses downward toward the toes. Most babies with jaundice have physiologic jaundice, which is the type caused by the natural process of breaking down red blood cells. If the baby's jaundice is caused by any other conditions, however, the healthcare giver will provide the parents with additional information for caring for the baby.
When to call the doctor
With short neonatal hospital stays, jaundice will not have peaked or become apparent at the time of hospital discharge. Therefore, infants at risk for severe hyperbilirubinemia should be identified so they can be observed closely both while in the hospital and after discharge. The parents need to be instructed on how to evaluate the infant for jaundice. They should look for it first in the face and upper body and if it progresses downward this means the concentration is getting too high and it is time to call the pediatrician. If there is an area of their living quarters that gets sunlight, it helps to let the baby lie there in only a diaper for a short period of time each day.
Diagnosis
Jaundice can be observed with the naked eye, but it is too difficult to estimate the variation in levels of bilirubin in that manner. Thus, if an infant begins to appear jaundiced, bilirubin levels will be ordered to determine the severity. Jaundice usually becomes apparent when total bilirubin levels exceed 5 mg/dL; however, the clinical significance of bilirubin levels depends on postnatal age in hours. A bilirubin level of 12 mg/dL may be pathologic in an infant younger than 48 hours but is benign in an infant older than 72 hours. In the determination of cause, it is suggested that laboratory testing be reserved for infants with nonphysiologic jaundice. In up to 50 percent of infants with severe jaundice, breastfeeding
and lower gestational age were the only causes identified despite extensive workups.
Treatment
The mainstay in treatment of hyperbilirubinemia is phototherapy, which is safe and widely available. Its effectiveness was demonstrated in a study by the National Institute of Child Health and Human Development. Multiple factors can influence the effectiveness of phototherapy, including the type and intensity of the light and the extent of skin surface exposure. Special blue fluorescent light has been shown to be most effective, although many nurseries use a combination of daylight, white, and blue lamps. In the early 2000s, fiberoptic blankets have been developed that emit light in the blue-green spectrum, which is light at a wavelength of 425–475 nm. Light at this wavelength converts bilirubin to a water-soluble form that can be excreted in the bile or urine. The intensity of light delivered is inversely related to the distance between the light source and the skin surface. Since phototherapy acts by altering the bilirubin that is deposited in the tissue, the area of the skin exposed to phototherapy should be maximized. This has been made more practical with the development of fiberoptic phototherapy blankets that can be wrapped around an infant.
Home-based care for neonatal jaundice has become more prevalent than hospital care, and the availability of fiberoptic blankets has made it possible. Infants receiving home phototherapy need daily visits by a nurse, who performs a physical examination and measures the total serum bilirubin level. If bilirubin levels continue to rise, hospital readmission should be considered. Discontinuation of home phototherapy is safe once the total serum bilirubin level has decreased to less than 15 mg/dL in healthy full-term infants older than four days. Office evaluation within two to three days of discontinuing home phototherapy is recommended.
Potential side effects of phototherapy used for elevated bilirubin levels, include watery diarrhea, increased water loss, skin rash, and transient bronzing of the skin. Many infants who are readmitted to the hospital because of hyperbilirubinemia are mildly to moderately dehydrated. Breastfeeding should be increased to every two to two and a half hours. Increased feedings can increase peristalsis and meconium passage, decreasing bilirubin resorption into circulation.
Full-term infants rarely require an exchange transfusion if intense phototherapy is initiated in a timely manner. It should be considered if the total serum bilirubin level is approaching 20 mg/dL and continues to rise despite intense in-hospital phototherapy. Exchange transfusion corrects anemia associated with the destruction
of red blood cells and is effective in removing sensitized red blood cells before they are destroyed. It also removes about 60 percent of bilirubin from the plasma, resulting in a clearance of about 30 percent to 40 percent of the total bilirubin. If a transfusion is not performed and bilirubin levels get higher, the infant progresses through three phases. In the first two to three days the infant is lethargic, has muscle weakness, and sucks weakly. Progression is marked by a tensing of the muscles, arching, fever, seizures, and high-pitched crying. In the final phase, the patient is hypotonic for several years.
Prognosis
The prognosis for physiological neonatal jaundice is generally very good. Very few infants ever have bilirubin levels greater than 20 mg/dL, which is the level that is correlated with kernicterus (an abnormal accumulation
of bile pigment in the brain and other nerve tissue that causes yellow staining and tissue damage). It rarely occurs with bilirubin levels lower than 20 mg/dL but typically occurs when levels exceed 30 mg/dL. Levels between 20 and 30 mg/dL associated with prematurity and hemolytic disease may increase the risk of kernicterus. There are long-term neurological problems when this occurs. Affected children have marked developmental and motor delays in the form of cerebral palsy and mental retardation may also be present.
Prevention
Elevated bilirubin in the neonate is the most common reason for hospital readmission in the first two weeks of life. Kernicterus is still relatively uncommon but has been on the rise with the mandated early postnatal discharge policies. Bilirubin-induced complications can be prevented by introducing a neonatal jaundice protocol to identify infants at risk for significant bilirubin increases, by ensuring adequate parental education and providing for follow-up care.
Parental concerns
Parents of a newborn need to be vigilant in monitoring changes in their infant. If the mother is breastfeeding, she should nurse the baby at least once every three hours to ensure the onset of milk production and to maintain hydration, which can also be evaluated by the number of wet diapers. Many pediatricians recommend seeing the infant at two weeks but if the parents feel it should be sooner due to alterations in the newborn's physical status, they should take the infant in for a visit.
KEY TERMS
ABO incompatability—The reaction that occurs with blood groups that are of a different type.
Cephalohematoma—A benign swelling of the scalp in a newborn due to an effusion of blood beneath the connective tissue that surrounds the skull, often resulting from birth trauma.
Kernicterus—A potentially lethal disease of newborns caused by excessive accumulation of the bile pigment bilirubin in tissues of the central nervous system.
Meconium—A greenish fecal material that forms the first bowel movement of an infant.
Oxytocin—A hormone that stimulates the uterus to contract during child birth and the breasts to release milk.
Peristalsis—Slow, rhythmic contractions of the muscles in a tubular organ, such as the intestines, that move the contents along.
Rh incompatability—A factor of blood classified as negative or positive and related to the reaction that occurs between different types.
Trisomy—An abnormal condition where three copies of one chromosome are present in the cells of an individual's body instead of two, the normal number.
BOOKS
Klaus, M. H., and A. A. Fanaroff. Care of the High-Risk Neonate, 5th ed. Philadelphia, PA: Saunders Company, 2001.
Olds, Sally, et al. Maternal-Newborn Nursing and Women's Health Care, 7th ed. Saddle River, NJ: Prentice Hall, 2004.
Seidel, H. M., et al. Primary Care of the Newborn. St. Louis, MO: Mosby, 2001.
PERIODICALS
Morantz, C., and B. Torrey. "AHRQ report on neonatal jaundice: Agency for Healthcare Research and Quality." American Family Physician (June 1, 2003).
ORGANIZATIONS
Association of Women's Health, Obstetric and Neonatal Nursing. 2000 L Street, NW, Suite 740, Washington, DC 20036. Web site: <www.awhonn.org>.
American Academy of Pediatrics. 141 Northwest Point Blvd., Elk Grove Village, IL, 60007. Web site: <www.aap.org>.
American College of Obstetricians and Gynecologists. 409 12th Street, SW, PO Box 96920, Washington, DC 20090. Web site: <www.acog.org>.
