What is the normal jaundice level for a baby?

Generally, whether a baby's jaundice level is normal needs to be determined according to the baby's age in days after birth. The normal bilirubin level for a full-term infant is usually below 12.9 mg/dL, while the normal bilirubin level for a premature infant typically remains under 15 mg/dL.

In full-term infants, the bilirubin level generally does not exceed 6 mg/dL within the first 24 hours after birth. Jaundice usually begins to appear and rise gradually on the second to third day after birth, peaking between the third and fifth day. However, the bilirubin level should still remain below 12.9 mg/dL at this stage. During this period, varying degrees of yellowing may appear on the baby's skin, sclera, and other areas. However, as long as the bilirubin level stays within the normal range and the baby is generally in good condition—for example, feeding normally and in good spirits—the jaundice is likely physiological and will resolve spontaneously.

Premature infants are more prone to jaundice due to relatively immature organ functions, and the jaundice may be more severe and last longer. In premature infants, the bilirubin level generally should not exceed 8 mg/dL within the first 24 hours after birth. The bilirubin level gradually rises on the second to third day, possibly approaching 15 mg/dL by around the third day, but should not exceed this value. During this period, regular monitoring of bilirubin levels is necessary, and timely treatment measures should be taken based on the changes in jaundice.

If a baby's bilirubin level exceeds the normal range, it is recommended to seek medical attention promptly for a clear diagnosis and targeted treatment to prevent serious complications and ensure the baby's health.