RH Incompatibility
Not yet clinically reviewed
This protocol was migrated from the earlier Pharmapedia and Ward Guide apps for educational use. Follow your hospital's own policies and consult seniors when in doubt.
Rh factor, also called Rhesus factor, is a type of protein found on the outside of red blood cells. The protein is genetically inherited (passed down from parents). If you have the protein, you are Rh-positive. If you did not inherit the protein, you are Rh-negative. The majority of people, about 85%, are Rh-positive.Rh incompatibility occurs when a woman who is Rh-negative becomes pregnant with a baby with Rh-positive blood. With Rh incompatibility, the woman’s immune system reacts and creates Rh antibodies. These antibodies help drive an immune system attack against the baby, which the mother’s body views as a foreign object.
Symptoms
- yellow amniotic fluid (During pregnancy, the amniotic fluid surrounding the baby will appear yellow due to bilirubin, which occurs when blood cells break down.)
- Jaundice (The skin and the whites of the baby's eyes will appear yellower than average)
- heart failure
Diagnosis
For most women, simple blood tests diagnose Rh incompatibility
- If you have Rh-negative blood, your doctor may order another blood test, called an antibody screen. This test checks whether your blood contains Rh antibodies. If your antibody screen comes back positive, you are at risk for Rh incompatibility.
- If you are Rh-negative and your antibody screen is negative, you will be given Rh immunoglobulin (RhIg) to prevent antibody formation. This is typically given around 28 weeks and within 72 hours of delivery. You may get a dose in early pregnancy if you have bleeding or other complications.
Treatment
Infants with mild Rh incompatibility may be treated with phototherapy using bilirubin lights
getting an injection of Rh immune globulins (RhIg) during your first trimester, during a miscarriage, or while having any bleeding during your pregnancy
transfusion is given through a needle inserted into a vein in the umbilical cord. Usually, additional transfusions are given until 32 to 35 weeks of pregnancy. Exact timing of the transfusions depends on how severe the anemia is and how old the fetus is.
Before the first transfusion, women are often given corticosteroids if the pregnancy has lasted 23 or 24 weeks or longer. Corticosteroids help the fetus's lungs mature and help prevent the common complications that can affect a preterm newborn.
The baby may need additional transfusions after birth. Sometimes no transfusions are needed until after birth.