I got a good question from a friend. Why is his bilirubin high? When normal red blood cells in the blood breakdown, the liver usually processes the products (one of which is bilirubin). Since premature babies have immature livers, the bilirubin can easily accumulate in the blood. The bilirubin usually reaches its peak on the 4th or 5th day of life, so hopefully Foster has reached his peak and it will gradually decrease. The most common treatment for high bilirubin is phototherapy under UV lights, which converts the bilirubin into a form that can be excreted in the stool or urine. To protect his eyes, Foster gets to wear super cool purple shades while sunbathing.