It can be difficult for parents to watch their newborn’s tender heel get poked with a needle for a blood draw. However, the necessity of this screening, alongside the information gleaned from just a few drops of blood, is critical to your baby’s health. Some of this blood is blotted onto a filter paper card and then sent off to the Texas Newborn Screening (NBS) Laboratory in Austin.
Some of the blood collected from the heel stick is also tested for bilirubin. This is done in hospital laboratories, and results are typically available within an hour.
Bilirubin is the end product of red blood cell breakdown, or turnover, which is usually a natural process in the body.
Jaundice, a yellowing of the skin and eyes, occurs when high levels of bilirubin are present in a baby’s bloodstream. The liver is responsible for metabolizing bilirubin, but the immature newborn liver doesn’t do a great job of processing it. Because of this, most newborns will have some kind of jaundice in the first few weeks of life. However, if bilirubin levels become too high, this unprocessed form of bilirubin can be absorbed by the baby’s brain and lead to permanent brain damage. For this reason, all newborns at Texas Children's Neonatal Intensive Care Unit have a bilirubin test before going home from the hospital.
The good news is that high bilirubin levels can be easily managed in almost all babies. Exposing the skin to phototherapy, particularly the blue-green light spectrum, is very effective in lowering bilirubin levels in newborns. This process converts bilirubin in the skin to a type of bilirubin more easily eliminated in urine and stool, so it’s necessary for the newborn to feed well to ensure good urine and stool output. In other words, all of those wet and poopy diapers are helpful in lowering bilirubin levels! When a newborn has an elevated bilirubin level, our lactation consultants assist mom with breastfeeding to ensure the baby is latching well and effectively transferring milk. Occasionally, your baby’s doctor might order supplementation with donor breast milk or formula to increase their intake.
In rare instances, phototherapy alone isn’t enough to manage dangerously high bilirubin levels. Some newborns might require a blood transfusion, or “blood exchange,” to lower these levels. These babies typically have something else going on, such as a different blood type than the mother or an inherited condition that causes red blood cell breakdown. Premature babies also face an increased risk of high bilirubin levels. While some (rare) risks come with a blood transfusion, the benefits far outweigh the risk of potential brain damage.
The best way to help prevent significant jaundice is to ensure your newborn is feeding often and effectively, although high bilirubin levels might be unavoidable for some babies with other medical conditions. It’s not safe to use sunlight exposure as “treatment” for neonatal jaundice. Most newborns will experience some jaundice within a few days of birth, and bilirubin levels are typically highest on day 4 or 5 of life. Thus, it’s imperative for all newborns to visit their primary pediatrician within a few days of going home from the hospital.