Jaundice of the skin in newborns

Jaundice of the skin in newborns: Comprehensive overview

Jaundice is a condition in which the skin and the whites of a newborn’s eyes acquire a yellowish tint. It is one of the most common conditions in infants, arising from an increased level of bilirubin in the blood. In most cases this is physiological jaundice, which is a safe and temporary adaptation process for the child to life outside the womb.

Mechanism of jaundice development

Bilirubin is a yellow pigment formed during the breakdown of red blood cells. In an adult’s body it is processed by the liver and excreted in the stool. In newborns this process differs:

• Massive red blood cell breakdown: After birth the infant’s body begins to replace fetal hemoglobin with "adult" hemoglobin. This is accompanied by the destruction of a large number of red blood cells and, consequently, the release of a large amount of bilirubin.
• Immature liver: The enzymatic systems of a newborn’s liver are not yet active enough to handle such a volume of bilirubin.

As a result, unprocessed (indirect) bilirubin accumulates in the blood. Because it is fat‑soluble, it easily penetrates the skin and mucous membranes, coloring them yellow. This condition is described in detail in our article "Jaundice of newborns: normal and pathology".

Types of jaundice and their differences

In addition to physiological jaundice, there are pathological types that require medical intervention. It is important to know their differences:

• Physiological jaundice: Appears on day 2‑3 of life, peaks on day 4‑5 and disappears by week 2‑3. The infant’s condition is not compromised.
• Pathological jaundice: May appear already within the first day, bilirubin level is very high and rises rapidly. It can be caused by Rh incompatibility, infections, genetic diseases.
• Breast‑feeding jaundice: Two types are distinguished. Breast milk jaundice – a safe condition related to milk composition, may last up to 2‑3 months. Insufficient feeding jaundice occurs when the infant receives little milk, slowing bilirubin elimination in the stool.

In any case, the degree of jaundice and bilirubin level should be assessed by a physician. Read about the importance of proper feeding organization for prevention in the article "Basics of breast‑feeding".