Newborn jaundice is common but nevertheless a source of significant anxiety for young parents. First, some background: jaundice is caused by a buildup of bilirubin–produced by the metabolism of hemoglobin from old red blood cells–in the bloodstream. Now, all human beings have a small amount of bilirubin in their bloodstream(< 2mg/dl) which is excreted by the liver and eliminated with stool. This process is how it works with “regular” people. In the fetus, bilirubin crosses the placenta and then is handled by mother’s liver. Once the baby is born and the umbilical cord is cut, then the baby is “on his own” and his liver must “take over.” But that doesn’t happen immediately-it usually takes 3-4 days for the infant liver to “jump start” and begin clearing bilirubin . The liver has an enormous capacity to detoxify the blood, so once it starts, only minute, innocuous amounts will persist. But meanwhile the bilirubin builds up and the baby can look a bit yellow–first on the face and, as the blood level increases, on the neck, trunk, and, rarely, the extremities.
So what’s the problem? Well, bilirubin is very insoluble in water based solution like human blood. If the level rises too high it can “precipitate out” of solution–like putting too much sugar in your coffee–forming crystals which can settle in the brain causing serious injury. The good news is that it’s very easy to monitor(check blood levels) and treat. “Phototherapy” (purple lights), sometimes holding breast feeding, and occasionally giving intravenous fluids are effective ways to control the bilirubin concentration until the “jump started” liver addressed the issue permanently.
Also, remember that jaundice is an “either/or” thing. If you don’t get to the precipitation point “magic number” then nothing happens. As I always say–its not brain damage at a level of 20 mg/dl and C-‘s if its 19. There are no adverse consequences whatsoever to having elevated bilirubin levels below the precipitation point and its so easy to prevent(again:just check the blood)–I have, thankfully, never seen it in >30 years as a pediatrician. We follow and treat it to keep from drifting towards that dangerous level.
Certain factors may increase jaundice:
- Breastfeeding–“Breast milk jaundice” is the most common cause of a yellow baby. It is completely innocuous and absolutely no reason to stop nursing.
- Premature baby
- Small baby
- Bruising caused by delivery trauma
- Certain blood group differences between parents, if baby inherits Dad’s blood–can cause jaundice. This is “ABO setup”and special to me–all 3 of my children were very jaundiced from this.
- There are medical conditions which can cause more pathological causes of jaundice.
Jaundice may be more serious if:
- It lasts > 2 weeks
- Associated with fever > 100.2
- Poor feeding or listless baby
- White cottage cheese colored stools
I am happy to report that, despite their jaundiced start to life, my 3 kids are healthy and proud to brag that they are all highly educated professionals. That is what I always assume will be the ultimate outcome for my jaundiced newborns.
So try not to worry too much, call with questions, and thanks for following.