Symptoms of neonatal jaundice

The increased bilirubin content of the blood colors the skin and the white of the eye yellow. At particularly high concentrations, the fat-soluble bilirubin can penetrate nerve cells and destroy them. This initially causes sluggishness and fatigue in the newborn as well as massive muscle weakness and a reduced need to drink.

In the further course of the disease, the baby becomes jumpy and bends its head backwards violently with simultaneous hyperextension of the entire body (opisthotonus). In the final stage, seizures and comatose states can occur until death occurs. In the so-called nuclear icterus, special parts of the brain are damaged, which can lead to unusual movements of hands and feet (choreoathetosis) as well as deafness.As a rule, developmental disorders and intelligence deficits can then also be expected. In the majority of cases, however, the prognosis is very good and no permanent damage is to be expected.

Forms of neonatal icterus

In paediatrics (pediatrics), different forms of newborn jaundice are distinguished: Physiological newborn jaundice: On the 3rd – 6th day of life of the newborn child, the so-called physiological newborn jaundice occurs. This recedes again until the 10th day of life. The development of physiological neonatal jaundice is based on the coincidence of increased hemoglobin degradation and immature liver function, resulting in an accumulation of unconjugated, water-insoluble bilirubin.

This so-called indirect bilirubin cannot be directly converted by the liver‘s UDP-gluoronyltransferase into direct and thus water-soluble bilirubin. This is why it is deposited temporarily and can be seen, for example, in the yellow skin color. The condition is called hyperbilirubinemia.

If the newborn baby is breastfed, the glucuronyltransferase may be inhibited by components of breast milk, which is called icterus. Icterus praecox: Icterus praecox, in contrast to “normal” newborn jaundice (see above), is a yellowing of the skin (icterus) that already exists on the first day of life. The bilirubin rises in the first 36 hours of life to values above 12mg/dl.

This metabolic disorder is usually caused by an AB0 blood group incompatibility between newborn and mother. Icterus gravis: In this form of icterus the concentration of bilirubin in the mature newborn exceeds 20 mg/dl. If the diagnosis is made in an immature newborn, the limit should be set lower.

Depending on the age (in weeks of pregnancy) and weight at birth, an icterus gravis already exists from a bilirubin concentration of 10 mg/dl. Icterus prolongatus: Icterus prolongatus is the name given to a newborn icterus that has existed for more than two weeks. Our next topic may also be of interest to you: Nucleicterus in babies Prolonged jaundice is the persistent occurrence of elevated bilirubin levels beyond the first week of life.

According to other classifications, it also occurs after the tenth or even the fourteenth day of life of the newborn. This means that degradation products of the blood pigment haemoglobin are measurable to an increased extent, but do not exceed the value of 15 mg/dl. Due to the increased levels of the breakdown product in the infant’s blood, a characteristic yellow coloration of the skin, the so-called jaundice, occurs.

About 3-15% of all newborns suffer from the prolonged form of bilirubin increase. Prolonged jaundice, like jaundice praecox (elevated bilirubin levels within the first day of life) and jaundice gravis (values above 15 mg/dl), is one of the pathological forms of neonatal jaundice and requires regular medical check-ups. In most cases, the prolonged form of jaundice is caused by unconjugated hyperbilirubinemia.

This means that, due to the fact that the liver function of the newborn is not yet fully developed, the conversion of the unconjugated, non-water-soluble breakdown substance bilirubin into its water-soluble form does not take place to a sufficient extent. This state is often maintained by breast milk components, as these can block the enzymes that are important for the solubility process of bilirubin. In this case, one also speaks of a mother’s milk icterus, which is, however, usually temporary and fades away without consequences.

Other reasons for a prolonged existence of elevated bilirubin levels can be, for example, hypothyroidism, bile stasis, changes in the bile ducts and liver disease in the newborn. In addition, there are numerous other reasons for prolonged jaundice, some of which are very serious and require comprehensive diagnostic clarification and specific therapy. You can read more about this topic here: Prolonged icterus