Welcome back! Click here for Part 1. Last time we left off with mom’s body sending anti-RhD antibodies through the placenta to her second baby.
What happens to baby?
In all cases of Rh disease, baby loses some RBCs – in fact, baby’s own immune system destroys the RBCs because they were marked with maternal antibodies. What happens next depends on how many antibodies baby was exposed to.
In mild cases, baby has slight anemia – too few oxygen-carrying RBCs. Baby might show no symptoms at all.
Baby might develop jaundice1 after he’s born. When RBCs are destroyed, they release their hemoglobin.2 Baby starts to break down the hemoglobin so he can recycle the iron, and one of the breakdown products is a yellow substance called bilirubin. In large amounts, it can damage baby’s brain. While he’s still in the womb, baby passes the bilirubin back to mom’s liver for disposal. However, right after birth, mom is no longer taking care of the bilirubin and baby’s liver doesn’t know what to do yet, so the yellow-colored substance accumulates in baby’s skin. Blue lights break down the bilirubin into small enough pieces that baby’s liver can handle it.3
In severe cases, baby loses a lot of RBCs. Baby’s heart is pumping harder and harder to get the remaining RBCs around his body to deliver oxygen. Sometimes, this effort is too much for the heart and baby dies.
How it’s treated
- the yellow-colored skin for which babies are placed under blue lights [↩]
- the red, oxygen-carrying protein [↩]
- The superficial cause of jaundice is always the same – excess bilirubin in the blood. However, all sorts of things besides blood type differences can cause an excess of bilirubin, some of which may be covered in another post. [↩]