Hemolytic disease of the newborn (HDN) is a blood disorder in a fetus or newborn infant. In some infants, it can be life-threatening.
This article provides a general overview. For more detailed information, see the specific disorder:
ABO incompatibility Rh incompatibility
HDN; Erythroblastosis fetalis
HDN may develop when a mother and her unborn baby have different blood types (called “incompatibility”). The mother produces substances called antibodies that attack the developing baby’s red blood cells.
The most common form of HDN is ABO incompatibility, which is usually not very severe. Other, less common types may cause more severe problems.
The least common form is Rh incompatibility, which can almost always be prevented. When this form does occur, it can cause very severe anemia in the baby.
HDN can destroy the newborn baby’s blood cells very quickly, which can cause symptoms such as:
- Edema (swelling under the surface of the skin)
Exams and Tests
Signs of HDN include:
- Anemia or low blood count
- Enlarged liver or spleen
- Hydrops (fluid throughout the body’s tissues, including in the spaces containing the lungs, heart, and abdominal organs), which can lead to heart failure from too much fluid
Which tests are done depends on the type of blood group incompatibility and the severity of symptoms, but may include:
- Complete blood count and immature red blood cell (reticulocyte) count
- Bilirubin level
- Blood typing
After birth, a
Infants with mild HDN may be treated with:
- Drugs used to treat allergic reactions (antihistamines)
- Drugs used to treat swelling and allergies (steroids)
- Feeding and fluids (hydration)
- Fluids given through a vein (intravenously)
- Light therapy using bilirubin lights
- Medicines to raise blood pressure if it drops too low
The severity of this condition can vary. Some babies have no symptoms. In other cases, problems such as hydrops can cause the baby to die before, or shortly after birth. Severe HDN may be treated before birth by intrauterine blood transfusion.
The most severe form of this disease, which is caused by Rh incompatibility, can be prevented if the mother is given a shot of a medicine called RhoGAM at certain times during and after her pregnancy. If you have had a baby with this disease, talk with your doctor if you plan to have another baby.