What is Hemolytic Disease of the Newborn

Hemolytic disease of the newborn (HDN) is when the red blood cells of your unborn baby (fetus) or newborn are destroyed. This breakdown of red blood cells is called hemolysis. It can lead to low amounts of red blood cells (anemia) and other problems.

What are the causes?

This condition is caused by a chain of blood reactions that begins during a woman’s pregnancy. The chain is as follows:

• In your first pregnancy, blood of the fetus crosses over into your blood during pregnancy or labor.
• A difference in blood types between you and your fetus causes your blood to react to the blood cells of your fetus. This reaction is called sensitization.
• When sensitized, your blood produces proteins that attack foreign substances (antibodies). These antibodies stay in your blood.
• In future pregnancies, these antibodies cross the placenta into the blood of your fetus.
• The antibodies then attack the red blood cells of your fetus, causing hemolysis.

HDN can occur when your blood type is O and your baby’s blood type is either A or B. It can also happen when you are Rh negative and your baby is Rh positive. There are other rare blood type differences that cause HDN.

HDN rarely occurs during the first pregnancy. If a baby is Rh positive, an injection of Rho (D) immune globulin is given to the Rh-negative mother. This will prevent HDN from occurring in future pregnancies. There is no medicine or treatment that prevents HDN from occurring in babies born to parents with other blood types.

What are the signs or symptoms?

Symptoms of this condition depend on how severe the disease is. Your baby’s symptoms may include:

• Pale appearance due to anemia.
• Yellow appearance (jaundice). This is from the buildup of waste products due to hemolysis.
• Difficulty breathing.
• Swelling of the body (edema).

In mild cases, your baby may have no symptoms.

How is this diagnosed?

This condition may be diagnosed before the birth of your baby. Diagnosis can be done based on:

• Blood tests. This can be done to check your blood type and to check your blood for sensitization. Blood tests on your fetus can be done as well.
• Tests on samples of the fluid that surrounds the baby in the uterus (amniotic fluid).
• Results of an ultrasound exam. This may show side effects of HDN in your fetus.

After birth, tests can be done on blood collected from the umbilical cord and your baby to check for HDN and its side effects.

How is this treated?

Before birth, treatment can include:

• Transfusion of red blood cells to treat anemia in your fetus. This is done by inserting a needle into a blood vessel in the umbilical cord. This is called in utero transfusion.
• Induction of early delivery if your fetus develops complications.

After birth, treatment may include:

• Transfusion of blood to treat anemia.
• Use of special lights to treat jaundice (phototherapy).
• Replacement of your baby’s blood with fresh blood (exchange transfusion). This exchange:
  • Removes some of the antibodies.
  • Treats anemia.
  • Treats jaundice.
• Oxygen or a breathing machine (ventilator) to treat breathing problems.
• Fluids given through an IV to treat low blood pressure and to give fluids if the baby cannot eat.
• Medicine and extra iron to help your baby make more red blood cells.

Follow these instructions at home:

• Follow instructions given by your baby’s health care provider.
• Keep all follow-up visits as told by your baby’s health care provider. This is important.

Contact a health care provider if:

• Your baby’s skin has new or worsening yellow color.
• Your baby seems less active than expected.
• Your baby is not feeding well.

Get help right away if:

• Your baby who is younger than 3 months has a temperature of 100°F (38°C) or higher.
• Your baby has trouble breathing. Watch for:
  • Rapid breathing.
  • Grunting sound when breathing out.
  • Sucking in of the spaces between and under the ribs.
  • Flaring of the nostrils.
  • Blue color around the lips.

Summary

• Blood reactions during pregnancy or labor can cause hemolytic disease of the newborn (HDN).
• Treatments for the disease may be given to your baby before or after birth.
• Close monitoring of your baby after birth is required to minimize the effects of HDN.