What to Know About Hemolytic Disease of the Newborn

Reviewed by Jabeen Begum, MD on November 17, 2021

Hemolytic disease of the newborn (HDN) is a blood disorder that is also called erythroblastosis fetalis. Hemolysis refers to the breakdown of red blood cells, and erythroblastosis is the production of immature red blood cells. Newborns with HDN show several common symptoms, even though each baby may experience it differently.

What Causes Hemolytic Disease of the Newborn?

The cause of hemolytic disease of the newborn is an incompatibility of blood types between mother and baby. Everyone has a blood type: either A, B, AB, or O. Along with a type, you also have an Rh factor, which can be positive or negative. HDN can happen if you and your baby have different blood types and Rh factors. Most commonly, this happens when the mother has a negative Rh and the father has a positive Rh.

If the baby is Rh-positive like its father, problems can occur if the baby’s red blood cells cross over to the mother. This normally happens during delivery, when the placenta detaches, but it can happen any time the blood cells of both mother and baby mix, such as during an invasive prenatal test before birth. When the two blood types meet, the mother’s body perceives the baby’s Rh-positive cells as a foreign invader. The mother’s body then calls upon the immune system to fight off these invading cells with antibodies.

Hemolytic disease of the newborn is more likely to occur in your second or third pregnancy than in your first. HDN isn’t very common in the U.S. because of early detection and treatment. In fact, only about 4,000 babies are born with HDN each year in the U.S.

What Are Symptoms of Hemolytic Disease of the Newborn?

During your pregnancy, you won’t notice any symptoms, and each baby may show HDN symptoms differently. However, your doctor may be able to detect HDN during your pregnancy. Some of the symptoms before birth are:

  • Mild anemia: your baby might have a low red blood cell count, making it difficult to carry oxygen from the lungs to other organs and tissues.
  • Severe anemia: to help make up for a low red blood cell count, your baby’s body may try to make more of them in the liver and spleen. This causes these organs to swell, and the new red blood cells don’t work properly, causing anemia to be even more severe.
  • Hydrops fetalis: if your baby’s body can’t regulate the anemia, that can lead to heart failure or severe buildup of fluid in their organs and tissues.

Symptoms of HDN can be seen after the baby is born. They include:

  • Hemolytic jaundice. Jaundice is actually quite common in newborns. A baby with hemolytic jaundice often has a yellowish coloring of the skin, umbilical cord, or the whites of their eyes. They may also look pale or swollen. The amniotic fluid may have a yellowish coloring. This comes from a pigment called bilirubin that forms when red blood cells break down. Babies with hemolytic jaundice might not appear yellowish right after birth, but it usually develops quickly. Typically, discoloration starts within 24 to 36 hours after birth.
  • An enlarged spleen or liver
  • Severe swelling all over their body
  • Pale skin (from the anemia)
  • Difficulty breathing

In some cases, babies may develop kernicterus. This takes place when the bilirubin buildup becomes so high in the baby’s body that it leaks into the brain. This can cause permanent brain damage.

What Is the Treatment for Hemolytic Disease of the Newborn?

HDN treatment depends on whether it is detected before or after birth. If your doctor finds hemolytic disease of the newborn before birth, your baby can have a blood transfusion to treat the anemia. These transfusions usually continue until the fetus fully develops and can be safely delivered. During your pregnancy, your doctor may give you corticosteroids, a medication that helps your baby’s lungs to develop. This medication can also help prepare your baby’s body for early delivery if necessary.

If your baby is having complications from HDN in the womb, your doctor may induce labor early as long as your baby is mature enough. Once born, your baby may need:

  • More blood transfusions, depending on the level of anemia
  • Fluids delivered intravenously if they have low blood pressure
  • Phototherapy, or a special kind of light to help your baby’s body to clear out the bilirubin
  • Oxygen, or a breathing machine, to help them breathe better
  • An exchange transfusion, a test that removes excess bilirubin from your baby’s body; it gives your baby fresh blood with normal levels of bilirubin.
  • Intravenous immunoglobulin (IVIG), a solution made from plasma that has antibodies that stimulate your baby’s immune system

Can Hemolytic Disease of the Newborn Be Prevented?

Hemolytic disease of the newborn is preventable. During your prenatal care visits, your doctor will most likely perform a blood test to learn your blood type. If necessary, your doctor can give you a medication called Rh immunoglobulin (RhoGAM) at around 28 weeks to stop your body’s antibodies from attacking your baby’s cells.

Show Sources


Boston Children’s Hospital: “Hemolytic Disease of the Newborn.”

Children’s Hospital of Philadelphia: “Hemolytic Disease of the Newborn.”

Dana-Farber Cancer Institute: “Hemolytic Disease of the Newborn.”

Memorial Hermann: “Hemolytic Disease of the Fetus and Newborn (HDFN).”

MERCK MANUAL Consumer Version: “Hemolytic Disease of the Newborn.”

Stanford Children’s Health: “Hemolytic Disease of the Newborn (HDN).”

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