Jaundice is a yellowing of the skin and/or whites of the eyes caused by high levels of bilirubin—a dark yellow-green or orange-red pigment—in the blood.
Jaundice, also called icterus or hyperbilirubinemia, is a very common condition in newborns. Newborn or neonatal jaundice , sometimes referred to as physiologic or physiological jaundice, affects more than half of all full-term newborns and 80 percent of premature newborns within the first few days of life. It commonly lasts for one to two weeks. Jaundice that is present at birth or that lasts more than a couple of weeks may be abnormal jaundice and a symptom of an underlying problem. Jaundice in older children or adults is a symptom of hepatitis (inflammation of the liver) or some other liver disorder.
Jaundice results from higher than normal levels of bilirubin in the blood. Bilirubin is a breakdown product of red blood cells. Red blood cells normally are removed and broken down in the spleen after about 120 days in circulation. Heme (component of hemoglobin in red blood cells that carries oxygen throughout the body) is broken down into bilirubin, which moves to the liver where it is processed and added to bile, a digestive fluid. The bile travels through the bile ducts to the intestine and is excreted in the stool.
Infants are born with excess red blood cells that are rapidly recycled by the spleen and liver, releasing bilirubin. This pigment gives a newborn's stools their yellow color. If more bilirubin is produced than can be processed by the liver, blood levels of bilirubin rise, and the excess is deposited in tissues causing the skin to appear yellow.
Although jaundice affects the majority of newborns, it often is more severe in Asian or Native American children. It also is more common in infants who are not breastfeeding efficiently, resulting in low fluid intake.
In 2001 the U.S. Centers for Disease Control and Prevention (CDC) reported that cases of brain damage associated with hyperbilirubinemia (called neonatal encephalopathy, bilirubin-induced brain injury, or kernicterus) had been increasing since about 1990, perhaps due to shorter hospital stays following birth. One cause of hyperbilirubinemia in seemingly healthy full-term or near-term infants is biliary atresia , an obstruction or inflammation of the bile ducts. This condition occurs in about one in every 15,000 live births, and girls are slightly more at risk than boys.
Causes and symptoms
Prior to birth the mother's liver processes bilirubin for the fetus. At birth, particularly with preterm births, an infant's immature liver may not be able to process all of the bilirubin formed as red blood cells are removed from circulation. The excess bilirubin causes jaundice by the third or fourth day after birth. The jaundice usually appears first on the face and progresses downward to the chest, abdomen, legs, and feet. If newborn feeding is delayed for any reason, such as illness, a digestive tract problem, or low fluid intake due to inefficient breast-feeding; the infant produces fewer stools, resulting in critically high blood levels of bilirubin and severe jaundice.
Most full-term babies with neonatal jaundice have no other symptoms. However, if bilirubin levels continue to rise, other symptoms may include:
- slow or reluctant feeding
Risk factors for hyperbilirubinemia include:
- birth more than two weeks before the due date
- jaundice within the first 24 hours after birth
- significant bruising or bleeding under the scalp caused by labor and delivery
- high bilirubin levels prior to hospital discharge
- difficulty breastfeeding, resulting in low fluid intake
- a parent or sibling who had high bilirubin levels at birth
Abnormal jaundice in newborns
Jaundice at birth or within the first 24 hours after birth can be a sign of abnormal jaundice. Abnormal jaundice can be dangerous, particularly in preterm or unhealthy newborns. Depending on the cause and extent of the jaundice, it also may be harmful in full-term infants.
The most common cause of abnormal jaundice is an ABO blood type incompatibility between mother and child. If the mother has O-type blood and the infant has either A or B blood type, or if the mother has A-type blood and the child has B-type or vice versa, the mother's antibodies circulating in the baby's blood attack the child's foreign blood type, causing damage to and destruction of the baby's red blood cells. This process, called hemolysis, is accompanied by the release of excess amounts of bilirubin.
In the past Rhesus (Rh) blood factor incompatibility between the mother and child was a major cause of kernicterus. An Rh-negative mother who was exposed to her fetus's Rh-positive blood during a previous pregnancy or delivery or who has accidentally received an Rh-positive blood transfusion has antibodies against Rh-positive blood cells. These antibodies can circulate in her Rh-positive newborn, initiating hemolysis and causing severe abnormal jaundice.
Rare causes of severe neonatal jaundice
Jaundice can result from a congenital (present at birth) malformation of the liver, bile ducts, or gall bladder. Jaundice resulting from a congenital defect usually does not appear until the baby is at least ten days old. Biliary atresia—the underdevelopment, inflammation, or obstruction of the bile ducts that carry bile from the liver to the gall bladder and small intestine—causes bile to build up in the liver and forces the bilirubin into the blood. The cause of biliary atresia was as of 2004 unknown, and jaundice may not appear until the infant is two to six weeks old. Other symptoms of biliary atresia include:
- dark brown urine due to excess bilirubin excreted in the urine
- light-gray or chalky-colored stools from lack of bilirubin excreted by the intestines
Jaundice that develops or persists after the second week of life also can be due to the following:
- breast milk jaundice (prolonged jaundice resulting from breastfeeding) that occurs when a chemical in the mother's breast milk interferes with the infant liver's ability to process bilirubin
- liver malfunction or damaged liver cells
- an enzyme deficiency
- an abnormality of the red blood cells such as anemia
- blood hemorrhaging
- a blood infection (sepsis)
- a liver infection such as hepatitis virus
- toxoplasmosis, an infection caused by an animal parasite and transmitted to the fetus via an infected mother (House cats can be carriers of toxoplasmosis.)
- an infection anywhere in the body that impairs the efficiency of the liver, including neonatal herpes simplex or salmonella
Such infections may be congenital, having been passed from the mother to the fetus, or may occur after birth.
Other causes of jaundice
There are numerous other causes of neonatal and childhood jaundice, including the following:
- liver cell damage resulting from a variety of conditions such as a viral infection, an adverse drug reaction, or drugs or other chemicals that damage the liver (Jaundice can be a late symptom of hepatitis in an older baby or child.)
- hemolytic jaundice caused by hemolytic anemia, in which red blood cells are turned over faster than usual
- Hodgkin's disease in teenagers
Symptoms accompanying jaundice caused by liver cell damage may include:
- abdominal pain
- swollen abdomen
When to call the doctor
A doctor should be consulted any time a child develops jaundice. Infants who are discharged from the hospital before bilirubin levels begin to rise, about three days after birth, should have their bilirubin level tested within a few days, particularly if they were preterm infants. Infants who become lethargic or reluctant to feed should be examined immediately, because symptoms can be signs of severe hyperbilirubinemia that can cause brain damage.
Newborns are examined under good light for signs of jaundice. A simple blood test, with a few drops of blood taken from the infant's heel, measures bilirubin levels in the blood. The test may be repeated frequently in a jaundiced newborn to assure that bilirubin levels are dropping. An instrument called a bilirubinometer can be held against the baby's skin to assess the level of jaundice. The Minolta/Hill-Rom Air-Shields Transcutaneous Jaundice Meter accurately measures bilirubin levels by shining lights of different colors through the skin and measuring the reflection, eliminating the need for blood tests via heel pricks.
If there is reason to believe that the newborn is suffering from an abnormal jaundice, additional tests must be performed. These include:
- blood cell counts to detect anemia
- tests for blood clotting function
- tests for excess destruction of red blood cells
- blood tests to assess liver function
- a liver biopsy, in which liver cells are removed and examined under a microscope to look for liver disease
- urine and stool samples to check for signs of bacterial or viral infection
Breast milk jaundice due to a reaction with a breast milk component is suspected when the more common causes of jaundice have been ruled out.
Biliary atresia must be detected before two months of age to prevent further liver damage. Diagnoses of biliary atresia and other liver conditions are made by imaging techniques, including the following:
- ultrasound scanning, which uses sound waves to obtain images of the liver, gallbladder, and biliary tract (Abdominal ultrasound can distinguish between jaundice caused by biliary atresia and jaundice caused by liver malfunction.)
- magnetic resonance imaging (MRI) of the liver
- computed tomography (CT) or computed axial tomography (CAT) scans, which use a thin, rotating x-ray beam to obtain an image
- endoscopic retrograde cholangiopancreatography (ERCP), in which a radiopaque dye that is visible on x rays is inserted into the upper portion of the small intestine so that it flows back up the biliary tract
- liver scans using radioactive dyes
Neonatal jaundice usually requires only observation. The infant may stay in the hospital for an extra day or return within the next few days for an examination. However, jaundice in a preterm baby may require intensive care. As the infant's liver matures and the excess blood cells are removed, the jaundice disappears. The child may be given additional fluids, possibly intravenously, to help remove the bilirubin. Frequent feedings lead to more frequent stools, which reduces the reabsorption of bilirubin from the intestines into the blood. Breast milk usually is considered superior to water or formula for relieving jaundice because breast milk produces stool with every feeding, thereby excreting bilirubin. Breastfeeding should not be discontinued because of neonatal jaundice.
If an infant's bilirubin levels are quite high or rising rapidly, phototherapy can prevent complications. The child is undressed and placed in a lighted incubator to stay warm. A high-intensity, cool, blue-fluorescent light is absorbed by the bilirubin and converts it into a harmless form than can be excreted in the bile and urine. An eye shield protects the baby's eyes. The infant is removed from the incubator for feeding. Other photo-therapy methods—such as a fiber optic bilirubin blanket—incorporate the light into a blanket so that the child can be breastfed during treatment or treated at home. Phototherapy is continued until bilirubin levels have returned to normal, usually within a few days.
Side effects of phototherapy may include:
- loose stools
- disinterest in breastfeeding
If bilirubin approaches a dangerous level, an exchange blood transfusion is used to rapidly lower it. A catheter is placed into the umbilical vein at the cut surface of the umbilical cord, and the newborn's blood is replaced with an equal volume of new blood. Rh incompatibility also may be treated by exchange transfusion.
Antibiotics may be used to prevent or treat a suspected infection in jaundiced infants. Babies with very severe jaundice have their hearing tested and are monitored for several months.
Surgery for biliary atresia must be performed within the first few weeks of an infant's life to prevent fatal liver damage. About 40–50 percent of infants with biliary atresia are candidates for replacement bile ducts leading from the liver into the intestine. Called the Kasai procedure or hepatoportoenterostomy, the obstructed ducts are replaced with sections from the infant's intestines. Infants with a duct obstruction within the liver itself usually require a liver transplant by the age of two.
Prolonged breast-milk jaundice may require breast-feeding to be halted for a few days until bilirubin levels drop. The breasts should be pumped in the interim so that the mother does not stop producing milk and breast-feeding can be resumed.
Neonatal jaundice disappears after one to two weeks. It may last slightly longer in breastfed infants. The jaundice does not harm the infant in any way, and breastfeeding should not be discontinued.
Severe untreated jaundice leading to kernicterus may result in the following:
- mental retardation
- cerebral palsy
Untreated biliary atresia leads to biliary cirrhosis, a progressive, irreversible scarring of the liver, by about two months of age. About 50 percent of bile duct replacement surgeries are successful, and the jaundice usually disappears within several weeks. Despite this success, the liver damage often progresses on to cirrhosis.
Breast-milk jaundice, resulting from a reaction to a breast milk component, is not dangerous. The baby's liver soon adapts to the problem and the jaundice disappears.
In 2004 the American Academy of Pediatrics issued revised guidelines for identifying and managing neonatal jaundice. They recommend:
Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.
Bile —A bitter yellow-green substance produced by the liver. Bile breaks down fats in the small intestine so that they can be used by the body. It is stored in the gallbladder and passes from the gall-bladder through the common bile duct to the top of the small intestine (duodenum) as needed to digest fat.
Bile ducts —Tubes that carry bile, a thick yellow-green fluid that is made by the liver, stored in the gallbladder, and helps the body digest fats.
Biliary atresia —An obstruction or inflammation of a bile duct that causes bilirubin to back up into the liver.
Bilirubin —A reddish yellow pigment formed from the breakdown of red blood cells, and metabolized by the liver. When levels are abnormally high, it causes the yellowish tint to eyes and skin known as jaundice. Levels of bilirubin in the blood increase in patients with liver disease, blockage of the bile ducts, and other conditions.
Hemolysis —The process of breaking down of red blood cells. As the cells are destroyed, hemoglobin, the component of red blood cells which carries the oxygen, is liberated.
Hyperbilirubinemia —A condition characterized by a high level of bilirubin in the blood. Bilirubin is a natural byproduct of the breakdown of red blood cells, however, a high level of bilirubin may indicate a problem with the liver.
Kernicterus —A potentially lethal disease of newborns caused by excessive accumulation of the bile pigment bilirubin in tissues of the central nervous system.
Phototherapy —Another name for light therapy in mainstream medical practice.
- that all newborns be assessed for their risk of developing severe jaundice, including measuring bilirubin levels before hospital discharge
- a follow-up visit occur within three to five days after birth when bilirubin levels are likely to peak
- breastfeeding a newborn at least eight to 12 times per day, since effective breastfeeding significantly reduces the risk of hyperbilirubinemia
- that parents be provided with written and oral information about the risks of neonatal jaundice
In cases of known Rh incompatibility, the mother is given an injection of RhoGAM, an immune globulin preparation, at about 28 weeks of pregnancy and again immediately after the child's birth. This destroys any Rh-positive fetal blood cells in the mother's circulation before her immune system can produce antibodies against them.
Parents should examine their infant in natural daylight and under fluorescent lighting for signs of jaundice. Jaundice may be harder to see in infants with darker skin. However, when a child's nose and forehead are pressed gently, the skin is white in healthy babies of all races, but yellowish if jaundice is present. If the skin appears yellow, the test should be repeated on the chest or abdomen. Parents also should be aware of symptoms that may accompany jaundice, including fussiness, unusual sleepiness, or difficulty feeding.
Mothers who are having difficulty breastfeeding should seek help. Although breast milk is an effective treatment for jaundice, breastfed babies may receive fewer calories than formula-fed babies during the first days of life, causing bilirubin levels to rise.
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American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098. Web site: http://www.aap.org.
American Liver Foundation. 75 Maiden Lane, Suite 603, New York, NY 10038. Web site: http://www.liverfoundation.org.
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Margaret Alic, PhD