Rh-negative blood type in the mother, combined with an Rh-positive blood type in the fetus, can lead to miscarriage due to Rh incompatibility.
Rh Incompatibility Explained
Rh incompatibility arises when a mother with Rh-negative blood carries a fetus with Rh-positive blood. This usually isn't a problem during the first pregnancy because the mother's blood is unlikely to have mixed with the fetal blood. However, during delivery, some fetal blood can enter the mother's system.
If this happens, the mother's immune system recognizes the Rh-positive blood cells as foreign and produces antibodies against them. This process is called sensitization.
In subsequent pregnancies with Rh-positive fetuses, these antibodies can cross the placenta and attack the fetal red blood cells. This can lead to:
- Hemolytic disease of the fetus and newborn (HDFN): The destruction of fetal red blood cells causes anemia, jaundice, and, in severe cases, heart failure and even death.
- Miscarriage: The severe anemia and complications from HDFN can ultimately lead to miscarriage.
Preventing Rh Incompatibility Miscarriage
Fortunately, Rh incompatibility miscarriage is preventable. Rh-negative mothers are given an injection of Rh immunoglobulin (RhoGAM) during pregnancy (around 28 weeks) and again after delivery if the baby is Rh-positive. RhoGAM prevents the mother's immune system from producing antibodies against Rh-positive blood cells.
Important Considerations
- Other blood group incompatibilities: While Rh incompatibility is the most well-known, other blood group incompatibilities (like ABO incompatibility) are typically less severe and rarely cause miscarriage. However, they can sometimes contribute to complications.
- Miscarriage is multifactorial: It's important to remember that many factors can cause miscarriage, and Rh incompatibility is just one potential cause. Other causes include genetic abnormalities, hormonal imbalances, infections, and underlying health conditions in the mother.
