Most new parents are very concerned about whether their children have developed jaundice, but often doctors have not done a good job of explaining to parents why jaundice is of any concern. Jaundice in newborns is very common, and almost every single infant will have some mild elevation of their “jaundice level”. The substance that causes the yellow coloring of the skin known as jaundice is called bilirubin, and it is this bilirubin level that becomes elevated and makes the skin and eyes appear yellow. Jaundice will progress in a head – down fashion, so the face will be yellow first, later the chest and body, and the eyes will become yellow as well. The yellow in the eyes is usually the last bit of jaundice to disappear.
Bilirubin is a breakdown product of the pigment in red blood cells, our oxygen carrying cells. Before birth, babies have a higher number of red blood cells due to the low levels of oxygen available in the womb. Once they are born, they begin to break down these excess red blood cells, leaving them with large amounts of bilirubin. The build up of this bilirubin causes their skin to become slightly yellow. Higher levels lead to increasing yellow discoloration , a.k.a. jaundice. Infants have an immature system for removal of bilirubin which causes it to build up faster than it would in an older child or adult. In addition, one of the ways that infants remove bilirubin is via urinating and stooling, and in the first days, some infants are not urinating or stooling enough to excrete all the bilirubin being produced. We always have some reabsorption of bilirubin in our intestinal tract, and in infants this reabsorption is also increased when they have less stooling. (This is the reason why, if your child is jaundiced, a nurse or doctor may recommend formula supplementation in the first few days to help increase their calorie intake and increase their stool output).
Why do we care about all of this bilirubin? If too much bilirubin builds up, it can start to deposit in specific regions of the brain, leading to permanent brain damage, so we are always very careful to monitor infants for jaundice and treat them if their bilirubin levels are getting too high. Brain damage does not typically occur until we reach levels greater than 25, but we recommend beginning treatment at levels much lower than that to prevent any risk of brain damage.
The treatment for jaundice is light, such as that we get from the sun. Unfortunately, for children with very significant jaundice, the amount of light one can get from the sun is too inefficient to safely ensure a decrease in jaundice levels. For that reason we use special “bili lights”. These are lights that emit specific blue wavelength light that makes bilirubin able to be easily excreted in an infant’s urine. It causes no skin damage or risk for skin cancer, but it can damage eyes, so we make sure all babies under bili lights wear eye protection all the time. The more time under the lights, and the more skin exposed, the better. For this reason infants are kept in only a diaper, and ideally left under lights all day, except 20-30 minutes every 2-3 hours for feeding. You can continue to breast feed while a baby is being treated for jaundice, and your doctor can tell you how often your child may be removed from light therapy based on his or her specific case.
It’s important to know that almost every baby has a small amount of jaundice, and most require NO treatment at all. We monitor levels transcutaneously (on the skin) and then, if a skin measurement is high, we confirm that with a blood test for bilirubin levels. Every hospital is slightly different in how often they check bilirubin levels. For infants with normal newborn jaundice, the problem is not lifelong, and once it has been adequately treated, poses no threat to your child’s health. If you have had a previous child who was treated for jaundice, let your pediatrician know, as this makes the likelihood other children would need treatment for jaundice slightly higher.