The Smiths were excited about the birth of their first child, healthy baby boy Max. With an uncomplicated vaginal delivery mom and Max were going to be discharged from the hospital on the second day. Max had passed his hearing test and survived his circumcision. I told the Smiths that I would like to see them in two days.
The office visit went well except for the fact that the baby was jaundiced. I asked them to stop by the lab at the hospital to measure Max’s bilirubin. I would call them with the results. The bilirubin level would determine what we would do next. Max’s dad looked a bit perplexed and said, “We will certainly do this, but what is jaundice?”
Jaundice is the yellowish discoloration of the skin that is caused by a pigment, bilirubin, which is the by-product of the breakdown of red blood cells, RBCs. Normally when a red blood cell is broken down, the pigment bilirubin is released into the bloodstream. It is carried to the liver where it is processed for excretion through the intestines, as in the stool, and the kidneys, as in the urine.
Newborns are born with an overabundance of RBCs. As these are broken down a large amount of bilirubin is delivered to their livers. The livers essentially get overwhelmed and cannot process all of the bilirubin efficiently. As a result, the bilirubin “spills” into the bloodstream and can cause a yellow tinge to the skin. Normally, the newborn’s liver catches up in a few days and can process all of the bilirubin without any problems. This usually occurs within five days. Consequently, all newborns usually have some degree of jaundice in the first few days of life.
We can measure the level of bilirubin in the bloodstream by doing a simple blood test. One can detect that a baby is jaundiced when the level is around 4 or 5. When it gets up into the teens the babies are jaundiced over most of their bodies. It is considered the standard of care to keep the bilirubin below the level of 20. When the level exceeds 20 there is a potential for the bilirubin to enter the central nervous system, staining the nervous tissue and causing permanent brain damage. Although the initial studies that proved this theory were in pre-mature, sick newborns, the goal is to keep the bilirubin level below 20 in ALL newborns.
Again most newborns develop some degree of jaundice in the first few days of life, peaking at 4 to 5 days and then dropping to a normal level. However, there are a number of conditions that can cause an increase in the level of bilirubin other than the normal physiologic jaundice. These are a result of an exaggerated breakdown of RBCs. They may include bruising from the birth process, a blood group incompatibility whereby mom’s blood type is O and the baby is type A or B, certain blood disorders such as spherocytosis, and a whole host of others. There are even a small number of babies that become jaundiced from an enzyme in the breast milk, although this tends to cause a persistent and lingering jaundice. For the sake of this paper, we will limit the discussion to the physiologic jaundice of the newborn.
In times past the routine practice of seeing a newborn for the first visit was at 10 to 12 days of life. This was to insure that the baby had regained the birth weight and was doing well.. Around the country it was found that babies were showing up for the first visit severely jaundiced. As a result, the American Academy of Pediatrics recommended that newborns be seen two days after leaving the nursery. This allows the pediatrician to monitor the degree of jaundice and to intervene early if indicated.
The most effective way to get rid of the bilirubin is by insuring that the baby is eating well and essentially “flushing” the gut. If this is not sufficient and the bilirubin level is nearing 20, the pediatrician may prescribe phototherapy, or bililights. The baby is placed in an isolette exposed to fluorescent-type lights which aid in the excretion of the bilirubin. This may require an admission to the hospital, although there are some companies that provide home-phototherapy units. Most babies only need 2 to 3 days of phototherapy before the level falls to a safe number.
Parents often ask about the benefits of direct sunlight to get rid of the bilirubin. In truth the sunlight is not generally strong enough since most newborns are fully dressed and swaddled exposing only the face. When a baby is under the bililights in the hospital they wear only eye patches. This is to increase the surface area of skin exposed to the fluorescent light to optimize the processing of the bilirubin.
The Smiths took Max to the lab as I requested. I got a call to inform me that his bilirubin was 11.4. Max’s parents were told the results. Since the baby was now four days old, and there was no set-up for exaggerated jaundice (mom’s blood type, increased bruising, etc.) I felt we were on the right track. But I wanted another bilirubin measurement in two days to be sure that the level had peaked and was on it’s way down. They agreed. The level two days later was 8.9. The jaundice was no longer an issue, and we didn’t need any more levels. If the repeat level had gone up, to perhaps 16.8, I would have gotten another bilirubin the next day since it had gone up 5.4 points in two days. There was no telling at what level it would peak. Remember, the goal is to keep the level below 20. When dealing with newborn bilirubins, it really becomes a “numbers game”.