Rh incompatibility screening
Rh incompatibility is a condition that occurs during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood.
"Rh-negative" and "Rh-positive" refer to whether your blood has Rh factor. Rh factor is a protein on red blood cells. If you have Rh factor, you're Rh-positive. If you don't have it, you're Rh-negative. Rh factor is inherited (passed from parents to children through the genes). Most people are Rh-positive.
Whether you have Rh factor doesn't affect your general health. However, it can cause problems during pregnancy.
Who is at risk
An Rh-negative woman who conceives a child with an Rh-positive man is at risk for Rh incompatibility.
Rh factor is inherited (passed from parents to children through the genes). If you're Rh-negative and the father of your baby is Rh-positive, the baby has a 50 percent or more chance of having Rh-positive blood.
Rh incompatibility doesn't cause signs or symptoms in a pregnant woman.
What you can do
Talk to your doctor about getting tested during every pregnancy.
Preventive service at no cost
Pregnant women, during the first pregnancy-related care visit
The USPSTF strongly recommends Rh(D) blood typing and antibody testing for all pregnant women during their first visit for pregnancy-related care.
Unsensitized Rh(D)-negative pregnant women
The USPSTF recommends repeated Rh(D) antibody testing for all unsensitized Rh(D)-negative women at 24 to 28 weeks' gestation, unless the biological father is known to be Rh(D)-negative.
Why screening is important
Rh incompatibility can be prevented with Rh immune globulin, as long as the medicine is given at the correct times. Once you have formed Rh antibodies, the medicine will no longer help.
Although the woman doesn’t have symptoms, it can lead to hemolytic anemia in the baby. Hemolytic anemia is a disorder in which the red blood cells are destroyed faster than the bone marrow can produce them. Symptoms may include:
- Abnormal paleness or lack of color of the skin
- Jaundice, or yellowing of the skin and eyes
- Dark-colored urine
- Intolerance to physical activity
- Enlargement of the spleen and liver
- Increased heart rate (tachycardia)
- Heart murmur
What the screening is
An Rh factor test is a basic blood test. The blood sample is usually taken during the first prenatal visit and sent to a lab for analysis.
- Talk with your doctor about scheduling an Rh immune globulin injection during your pregnancy and remind your healthcare team of your Rh status during labor.
- Administration of Rh(D) immunoglobulin.
- If an Rh(D)-positive infant is delivered, a dose of Rh(D) immunoglobulin.
- Unless the biological father is known to be Rh(D)-negative, a full dose of Rh(D) immunoglobulin is recommended for all unsensitized Rh(D)-negative women after amniocentesis and after induced or spontaneous abortion.