Hemolytic Disease of the Newborn | Symptoms & Causes

What are the symptoms of hemolytic disease of the newborn?

Each child may experience different symptoms of hemolytic disease of the newborn (HDN). The most common symptoms of HDN are:

  • pale skin
  • yellowing of the amniotic fluid, umbilical cord, skin and eyes
  • enlarged liver or spleen
  • severe swelling of the body

During pregnancy, it is possible for symptoms to include:

  • Mild anemia: When the baby’s red blood cell count is deficient, his blood cannot carry enough oxygen from the lungs to all parts of his body, causing his organs and tissues to struggle.
  • Hyperbilirubinemia and jaundice: The breakdown of red blood cells produces bilirubin, a brownish yellow substance that is difficult for a baby to discharge and can build up in his blood (hyperbilirubinemia) and make his skin appear yellow.
  • Severe anemia with enlargement of the liver and spleen: The baby’s body tries to compensate for the breakdown of red blood cells by making more of them very quickly in the liver and spleen, which causes the organs to get bigger. These new red blood cells are often immature and unable to function completely, leading to severe anemia.
  • Hydrops fetalis: When the baby’s body cannot cope with the anemia, his heart begins to fail and large amounts of fluid buildup in his tissues and organs.

After birth, possible symptoms include:

  • Severe hyperbilirubinemia and jaundice: Excessive buildup of bilirubin in the baby’s blood causes his liver to become enlarged.
  • Kernicterus: Buildup of bilirubin in the blood is so high that it spills over into the brain, which can lead to permanent brain damage.

What causes HDN?

HDN occurs when the blood types of a mother and baby are incompatible. If the baby’s incompatible red blood cells cross over to their mother, through the placenta during pregnancy or at delivery, the immune system sees them as foreign and responds by developing proteins called antibodies to attack and break them down. This can lead to several complications that range from mild to very severe.

The mother’s immune system also keeps these antibodies in case the incompatible red blood cells appear again, making them “sensitized.” Because of this, HDN is more likely to occur during a second or subsequent pregnancy, or following a miscarriage or abortion.

A person’s blood type is determined by the presence of two different types of proteins, called antigens. The A, B and O antigens represent the classification of a person’s blood as Type A, B, AB or O. If a person also has the Rh factor antigen, his blood is Rh -positive, and if not, it is Rh-negative.