Learn The BasicsHemolytic disease of the fetus and the newborn (HDFN) is a red blood cell disorder that develops because of the incompatibility between the blood of a pregnant woman and her fetus.
Here are some frequently asked questions about HDFN and answers to them.
Who can be diagnosed with HDFN?
HDFN develops when the blood type of a pregnant woman does not match that of her fetus. The mismatch might be between the Rh factor, i.e. the mother is Rh-negative and the fetus is Rh-positive, or between A, B, AB or O blood types. However, the latter is rarer.
How do I know if my baby is at risk of developing HDFN?
If a mother is Rh-negative and the father of the baby is Rh-positive, there is a chance that the baby will also be Rh-positive. In this case, they may be at risk of developing HDFN.
Also, if you already have been sensitized, or your body already started making antibodies against red blood cell proteins from your baby whose blood was incompatible with yours, your second baby may be at a higher risk of developing HDFN.
How can I tell if my baby has HDFN while pregnant?
HDFN does not cause any symptoms in the pregnant woman, so it is not possible to “feel” that your baby is developing HDFN.
However, there are tests that can identify HDFN in a fetus, such as a maternal blood test to assess the presence of antibodies, an ultrasound to assess whether the baby’s organs are enlarged and a Doppler ultrasound of the middle cerebral artery (MCA) to see if the baby has fetal anemia.
If I already had a baby with HDFN, will my second baby also have the disease?
This depends on whether the blood of the second baby is also incompatible with yours. If not, the second baby will not develop HDFN.
However, if the blood of your second baby is also incompatible with yours, their risk of developing HDFN is higher. This is because your body keeps the antibodies that it made during the first pregnancy, and these attack the red blood cells of the second baby.
Are there any treatments?
HDFN is a disease that can be treated. In case of severe anemia, a blood transfusion can be done even before the baby is born.
Other treatment options include phototherapy, intravenous fluids and intravenous immunoglobulin G (IVIG) that aim to reduce the levels of bilirubin, the harmful substance that is formed when the red blood cells are broken down.
There is also a new experimental therapy being developed called nipocalimab, which is injected into the mother’s bloodstream to reduce the levels of circulating antibodies that are known to be associated with HDFN. If approved, nipocalimab would be the first new treatment for HDFN in 30 years.
Can HDFN cause long-term problems?
If the bilirubin is not eliminated from the baby’s body efficiently, it can cross the blood-brain barrier and cause permanent neurological damage. This is called kernicterus.
If adequate treatment is given, HDFN is often a short-term condition, as the antibodies that the mother’s body produces against the red blood cells of the baby disappear within eight to 12 weeks.
Reviewed by Debjyoti Talukdar, M.D., on September 26, 2023.
