It’s very common for newborns to become jaundiced by the second or third day of life. Jaundice is a medical condition that presents with yellowing of the skin or sclera (whites of the eyes). It is due to a build up of bilirubin in the baby’s system.

Bilirubin is a breakdown product of red blood cells. Red blood cells live for three months after which the body breaks them down. Tens of thousands of red blood cells are destroyed and remade every day. Part of the breakdown process involves the release of bilirubin into the circulation. Before birth, a baby’s mother helps clear bilirubin from his blood. (Bilrubin is removed from the body by the liver.) Once the baby is born, he has to take over this process himself. Like many things, a newborn’s ability to process bilirubin is immature. As a result, bilirubin builds up in the circulation and can be seen in the baby’s skin.

Bilirubin is not dangerous to newborns unless it gets very high. The hospital staff follows standard protocols to make sure bilirubin levels stay in the safe range. In the past, this was done by visually checking the baby’s skin color. Nowadays, the bilirubin is checked every eight hours by placing a bilirubin meter on the baby’s forehead. If the reading is higher than expected for the baby’s age, the nurse will order a blood test to confirm the reading.

Most of the time, nothing needs to be done to treat a baby’s bilirubin. If the level continues to rise, the doctor may do additional blood tests, supplement the baby with formula or treat the bilirubin with something called phototherapy. This involves exposing the baby’s skin to ultraviolet light that increases bilirubin breakdown.

Because parents are commonly discharged when their newborn is 48 and 72 hours old, jaundice may not be noticed during your time in the hospital. When you have your first post-hospital visit, the doctor will carefully assess the baby’s skin to make sure he hasn’t gotten jaundiced since his discharge from the nursery. If necessary, additional blood tests and recommendations will be made at that time.

It is important for you to know that jaundice in the immediate newborn period is different from jaundice at any other time in a child’s life. If you notice that your one to 2-month-old baby is jaundiced, you should promptly call your doctor for an appointment.