The diagnosis of jaundice in their newborn baby is often very frightening to new parents. They immediately begin to think something is very wrong with their infant, and may not be fully informed about the facts, which are actually very reassuring.
It is very common
Because jaundice is such a common condition, some medical professionals don’t take the time to explain all the details, because they deal with jaundiced babies every day. However, when the baby in question is your own precious newborn, you need to get as much information as possible to put your mind at ease. Nearly all infants are jaundiced to some degree. In the vast majority of cases, newborn jaundice is a normal process, which many researchers feel may even serve protective functions, such as guarding the infant from the effects of oxygen free radicals. It makes sense that something that occurs in the majority of babies so routinely may be part of nature’s plan for the human infant. Jaundice occurs when a yellow pigment called “bilirubin” accumulates in the tissue, especially the skin, where you can see it as a yellowish or orangish tint. In adults or older children, jaundice is considered a pathological condition, but this is rarely the case with newborns. The very common type of jaundice that most babies experience is called normal, or “physiologic” jaundice. Physiologic jaundice is not a disease — it is nearly always a harmless condition with no adverse after effects, as long as the bilirubin count doesn’t reach dangerous levels.
How jaundice occurs
Before babies are born, they need high levels of red blood cells in order to get oxygen from their mother’s blood. Immediately after birth, when they begin breathing high-oxygen blood outside the womb, they no longer need their fetal hemoglobin. The red blood cells containing fetal hemoglobin now need to be broken down and eliminated from their bodies. Bilirubin is a by-product of the breakdown of these extra blood cells, and is removed from the bloodstream by the liver and excreted in the stool. It accumulates in the meconium (fetal stool — the black, tarry stuff that the baby excretes the first couple of days after birth) and if not excreted, can be re-absorbed into the baby’s system. The newborn’s immature liver may not be able to process and excrete the bilirubin fast enough in the first days after birth, so jaundice often develops. This is especially common in premature infants.
Bilirubin is measured in milligrams per deciliter of blood, or mg/dl. The average level for an adult is 1mg/dl. The average full-term newborn will have a peak level of 6mg/dl on the third or fourth day of life. Levels usually go down to about 2 to 3mg/dl by the end of the first week, gradually reaching the adult value of 1mg/dl by the end of the second week. It usually takes the newborn’s liver a week or two to mature enough to handle the build-up of bilirubin in the blood. It is important to know that there is no evidence that bilirubin levels of less than 20mg/dl during the first week of life, and less than 25mg/sl after that have any harmful effects of healthy, full-term babies.
So, if jaundice is such a normal condition, why all the concern? Because there are rare medical conditions which cause bilirubin to rise to dangerous levels, and can cause brain damage. Years ago, before we had the diagnostic tools and treatment options that we have today, some babies with very high bilirubin levels suffered from a condition called bilirubin encephalopathy, or kernicterus. This is rarely seen today, and then usually only in very premature or sick babies. Doctors today monitor bilirubin levels very carefully, and initiate treatment well before levels get high enough to cause problems. There are three types of jaundice: Normal, or physiologic jaundice, affecting the majority of newborns; pathologic jaundice, caused by medical conditions such as blood type incompatibilities (the most common cause), as well as prematurity, infection, liver damage from rubella, syphllis or toxoplasmosis, and metabolic problems such as hypothyroidism; and late-onset, or breastmilk jaundice (probably caused by a factor in some mothers’ milk that seems to delay or prolong the excretion of excess bilirubin).
It is important to understand the different types of jaundice, because each has different causes, consequences and treatments.
Types of jaundice
Physiologic jaundice affects nearly all newborns to some degree. It is more prevalent in certain ethnic groups, such as Chinese, Japanese, Korean, Hispanic and Native Americans. If you define jaundice as bilirubin levels of greater than 10mg/dl, one study found that Japanese newborns were more than three times as likely to be jaundiced as white newborns. Babies who are premature or are low birth weight are more likely to become jaundiced. Babies who don’t feed often enough during the early days, and who don’t stool often, are also more likely to become jaundiced. This underscores the importance of early, frequent feedings. Colostrum (the sticky yellow fluid produced before the milk comes in) acts as a laxative. Bilirubin accumulates in the baby’s stools, and if it isn’t excreted, it re-circulates in his system. Frequent stooling helps lower bilirubin levels.
In the baby with physiologic jaundice, bilirubin levels will usually peak between the third and fifth days of life and are usually less than 12mg/dl. Occasionally they will go higher than 15mg/dl. Most doctors will monitor levels closely during this time, checking the baby’s levels with a blood test, pricking his heel, toe or finger. If the levels are rapidly rising, or are 20mg/dl or higher (lower levels are used with premature infants), phototherapy is often suggested. This is a treatment which involves exposing skin to blue range light which breaks down the bilirubin and makes it more easily excreted.
Years ago, nurses found that babies who were in beds near sunny windows had lower bilirubin levels. Researchers then found that phototherapy can make bilirubin levels drop quickly. Until the past few years, babies with high bilirubin levels had to be in the hospital for phototherapy treatments. Now, with new technology, babies can receive phototherapy at home using bili-blankets, provided by home health care providers. In most cases, bilirubin levels drop rapidly after phototherapy is initiated, and once the levels begin to go down, they almost always continue to decline. Usually only a day or two or therapy is needed. Most cases of physiologic jaundice will resolve without the use of phototherapy.