When does jaundice typically appear in newborns?

When Does Jaundice Typically Appear in Newborns?

Jaundice is a common and usually harmless condition that can occur in newborns, typically manifesting as a yellowing of the skin and the whites of the eyes. This condition is caused by an excess of bilirubin, a yellow pigment produced during the normal breakdown of red blood cells. In newborns, the developing liver is not always fully efficient at processing and removing bilirubin from the bloodstream, leading to its accumulation and the subsequent yellowing.

In the UK, as in many other parts of the world, newborn jaundice typically appears within the first few days after birth. Most babies will show signs of jaundice between the second and fourth day of life. This is often referred to as "physiological jaundice" and is considered a normal response of the body adjusting to postnatal life. For many newborns, this type of jaundice will resolve naturally by the time they are about one to two weeks old, as the baby's liver matures and is better able to process bilirubin effectively.

There are several factors that can influence the onset and severity of jaundice in newborns. Premature babies, for example, are more likely to develop jaundice because their livers are even less developed than those of full-term infants. Additionally, breastfeeding can sometimes lead to what's known as "breastfeeding jaundice." This condition can arise if the baby is not nursing well enough, leading to dehydration and an increased concentration of bilirubin. In contrast, "breast milk jaundice" might appear after the first week of life and is related to substances in the mother’s breast milk that affect bilirubin processing, although this is relatively rare.

It is crucial for healthcare professionals to monitor newborns for signs of jaundice, especially within the first 72 hours of birth, to ensure that it does not reach dangerous levels. In the UK, guidelines recommend that newborns should be examined for jaundice at every opportunity, particularly in the first five days. This is typically done by visually inspecting the baby's skin and eyes, supplemented if necessary with more accurate tests like a transcutaneous bilirubinometer or a blood test to measure bilirubin levels.

In most cases, jaundice in newborns is mild and resolves itself. However, if left untreated, severe jaundice can lead to complications such as kernicterus, a type of brain damage that can result from very high levels of bilirubin in the blood. Therefore, early detection and appropriate management are crucial. Treatment options are available and might include enhanced feeding strategies or phototherapy, where the baby is placed under a special light that helps break down bilirubin in the skin.