by Jack Newman, MD, FRCPC
Here's What You'll Find Below:Two types of jaundice
So-called breastmilk jaundice
Jaundice is due to a buildup in the blood of bilirubin, a yellow pigment that comes from the breakdown of old red blood cells. It is normal for old red blood cells to break down, but the bilirubin formed does not usually cause jaundice because the liver metabolizes it and gets rid of it into the gut.
The newborn baby, however, often becomes jaundiced during the first few days because the liver enzyme that metabolizes bilirubin is relatively immature. Furthermore, newborn babies have more red blood cells than adults, and thus more are breaking down at any one time; as well many of these cells are different from adult red cells and they don't live as long. All of this means more bilirubin will be made in the newborn baby's body.
If the baby is premature, or stressed from a difficult birth, or the infant of a diabetic mother, or more than the usual number of red blood cells are breaking down (as can happen in blood incompatibility), the level of bilirubin in the blood may rise higher than usual levels.
The liver changes bilirubin so that it can be eliminated from the body (the changed bilirubin is now called conjugated, direct reacting, or water soluble bilirubin -- all three terms mean essentially the same thing). If, however, the liver is functioning poorly, as occurs during some infections, or the tubes that transport the bilirubin to the gut are blocked, this changed bilirubin may accumulate in the blood and also cause jaundice.
When this occurs, the changed bilirubin appears in the urine and turns the urine brown. This brown urine is an important clue that the jaundice is not "ordinary." Jaundice due to conjugated bilirubin is always abnormal, frequently serious and needs to be investigated thoroughly and immediately. Except in the case of a few extremely rare metabolic diseases, breastfeeding can and should continue.
Accumulation of bilirubin before it has been changed by the enzyme of the liver may be normal -- "physiologic jaundice" (this bilirubin is called unconjugated, indirect reacting or fat soluble bilirubin). Physiologic jaundice begins about the second day of the baby's life, peaks on the third or fourth day and then begins to disappear.
However, there may be other conditions that may require treatment that can cause an exaggeration of this type of jaundice. Because these conditions have no association with breastfeeding, breastfeeding should continue. If, for example, the baby has severe jaundice due to rapid breakdown of red blood cells, this is not a reason to take the baby off the breast. Breastfeeding should continue in such a circumstance.
There is a condition commonly called breastmilk jaundice. No one knows what the cause of breastmilk jaundice is. In order to make this diagnosis, the baby should be at least a week old, though interestingly, many of the babies with breastmilk jaundice also have had exaggerated physiologic jaundice. The baby should be gaining well, with breastfeeding alone, having lots of bowel movements, passing plentiful, clear urine and be generally well (see the information sheet Is my Baby Getting Enough Milk? and see also the video clips at the website nbci.ca).
In such a setting, the baby has what some call breastmilk jaundice, though, on occasion, infections of the urine or an under functioning of the baby's thyroid gland, as well as a few other even rarer illnesses may cause the same picture. Breastmilk jaundice peaks at 10-21 days, but may last for two or three months.