Jaundice is a relatively common condition in newborn infants, affecting up to 50-60% of all babies. It is more common in breastfed infants. It is usually harmless and goes away on its own, though it does sometimes cause some anxiety on the part of parents and often requires careful monitoring.
What is it?
The term jaundice refers to the yellowing of the eyes and skin. It is caused by an elevation of a substance in the blood called bilirubin. Bilirubin comes from the breakdown of red blood cells. It is removed by the liver and excreted through the intestines. A variety of conditions can cause jaundice or elevated bilirubin levels (hyperbilirubinemia), including many liver diseases and conditions in which a lot of red blood cells are destroyed.
The concern about jaundice is that very high levels of bilirubin can cause brain damage, a condition called kernicterus or bilirubin encephalopathy. It is a poorly understood disease but seems to be more common with very high bilirubin levels. Cases have occurred with lower levels, particularly in newborns that are ill. The goal of monitoring and treating newborn jaundice is to prevent kernicterus.
Symptoms
- The whites of the eyes become yellow to orange in color.
- The skin becomes yellow, starting with the face and working its way down the body as the jaundice level goes higher.
- Jaundice makes some babies sleepier and therefore harder to wake up for feedings.
Causes
There are several causes of jaundice in newborns. In reality, a variety of factors predispose the infant to jaundice. Some amount of elevated bilirubin is thought to be normal; bilirubin is an antioxidant, and elevated levels may protect the newborn from damage due to the stress of delivery and transition to living outside its mother. Babies normally lose water weight during the first few days, and this increases the concentration of all substances in the blood and body fluids including bilirubin. Babies are also born with extra red blood cells, which increases the amount of bilirubin being produced. Also, the concentration of bilirubin is high in meconium, and some is absorbed by the body until the meconium is eliminated. Babies often have some bruising or bleeding into the scalp from delivery, which is normal; however, this increases the destruction of red blood cells. Lastly, in many babies the liver is slow to start processing bilirubin for several days. All of these factors combine to predispose the baby to a bilirubin level high enough to cause jaundice.
Jaundice is more common in premature infants and in infants of East Asian, Mediterranean, and Native American ethnic groups. It is also more common in siblings of children who had jaundice as a newborn.
Physiologic jaundice
This is normal newborn jaundice; the term physiologic implies that it is part of the normal body metabolism. It also implies that there is no specific cause. For all of the reasons listed above, babies are prone to develop jaundice, and some level of elevated bilirubin is likely normal and protective.
Breastfeeding jaundice
This is probably an unnecessary term; it is simply physiologic jaundice in a breastfed baby. Because breastfed babies lose a little more water weight than formula fed babies (which is normal), they are more prone to develop jaundice. This term developed perhaps because the treatment used to be to stop breastfeeding for several days and use formula instead, and then resume breastfeeding. This is no longer considered necessary or desirable. However, for some reason many doctors still seem to recommend this treatment. Interrupting breastfeeding is not necessary; jaundice rarely rises to a level requiring treatment, and parental anxiety can be relieved by education and careful monitoring. Perhaps it is just easier for doctors to tell mothers to give formula instead. However, not only is this not the healthiest option, resuming breastfeeding is often difficult and unsuccessful. It is almost never necessary to stop breastfeeding because of jaundice.
Breastmilk jaundice
In breastmilk jaundice, there is a substance in the breastmilk which slows down the baby’s processing of bilirubin in the liver. It is a benign condition which will go away. Breastmilk jaundice usually starts later than breastfeeding or physiologic jaundice and the two may overlap. It typically starts about 4-7 days of age and remains at a low level for several months. It can be relieved by stopping breastfeeding for 2-3 days and then resuming; however, this is unnecessary in almost all cases, unless the parent strongly desires for the jaundice to go away.
Blood type incompatibility
Sometimes when the mother and the baby have different blood types, maternal antibodies against the baby’s blood type cross the placenta and lead to increased red blood cell destruction. This increases the amount of bilirubin being produced. ABO incompatibility is usually not severe but it does tend to go higher than physiologic jaundice. This is most common when the mother is type O and the baby is type A or B. Rh incompatibility can be much more severe. If an Rh-negative mom has a Rh-positive baby, she can develop Rh antibodies. In the next pregnancy, if the baby is Rh-positive, her antibodies can attack the red blood cells of the fetus leading to birth defects or fetal death. Sometimes the baby is born without any defects but then develops jaundice. This condition is preventable by giving the mother RhoGAM before that next pregnancy.
Other causes
Other causes include metabolic diseases, infections and liver diseases. These are usually more severe and have other symptoms.
Clinical course
Physiologic and breastfeeding jaundice usually starts at 2-3 days of life. The bilirubin level usually peaks around day 5-7 and then decreases without treatment. It is usually completely resolved by 1-2 weeks of life. Breastmilk jaundice usually starts around day 4-7 and reaches a plateau, then remains at a low level for several weeks, then resolves by itself without treatment. Jaundice due to blood type incompatibility can vary in severity; it can start at birth and rise quickly, requiring treatment, or it can be just like physiologic jaundice. Jaundice due to other diseases often starts earlier and is more severe; there are usually other symptoms as well, depending on the disease.
Bilirubin levels are usually measured using a blood test. However, there is now a device that can measure it by shining a light through the skin. However, this device is not as accurate as the blood test. Many hospitals are now using the light device to measure all infants prior to discharge as a screening test.
Treatment
- The main treatment is actually careful monitoring, either by appearance or by blood tests. There are graphs based on the baby’s age (in hours) and bilirubin level that can be used to predict whether the level will become treatable or not. If the initial level indicates a risk of it becoming high enough to treat, then the level is usually monitored daily until it stops rising and starts to fall.
- Increasing the amount of breastmilk or formula intake can help significantly. Babies with jaundice should be fed every 2 hours when possible.
- Putting the baby in sunlight is a common home treatment but it probably does not help very much. On the other hand, it does not hurt as long as the baby does not get sunburned.
- If the level is getting too high, phototherapy is started. A blue-colored ultraviolet light is used and most of the baby’s skin is exposed to the light. This can usually be done at home now, often with the lights embedded in a blanket. The light converts bilirubin into a compound that can be filtered and excreted by the kidneys.
- In extreme cases, a special kind of blood transfusion (an exchange transfusion) is required. This procedure is difficult to perform and can have complications. Phototherapy is actually used to prevent the level rising high enough to have to perform an exchange transfusion. These are not performed very often anymore.
