When you’re pregnant, you’ll get a number of health-related tests done as part of your care. One of the first tests you receive will be to confirm your blood type and Rh factor. Many people don’t know their blood type or Rh factor, but it’s important to know during pregnancy, as it can potentially affect the baby.
Read on to learn more about why you should know your blood type during pregnancy and why it matters.
What is the Rh factor?
The Rh factor is a protein found on the surface of your red blood cells. Not everyone carries this protein. People who do carry the Rh protein have a blood type that is Rh-positive and people who do not carry this protein have a blood type that is Rh-negative.
If you’re Rh-negative and the baby you’re carrying is Rh-positive, this is called Rh incompatibility.
What is Rh incompatibility?
Rh incompatibility occurs when the mother is Rh-negative and the baby is Rh-positive. If the blood of an Rh-positive baby gets into the bloodstream of an Rh-negative woman, her body will recognize the Rh-positive blood as foreign and produce anti-Rh antibodies to try to destroy it. This can cause health problems for the baby.
Why is Rh incompatibility a problem?
Anti-Rh antibodies can cross the placenta and attack the fetal blood cells, which can lead to health problems like anemia or jaundice in a newborn along with other serious conditions.
How is Rh incompatibility treated?
Knowing your Rh status early in your pregnancy is important because Rh incompatibility problems can be prevented with treatment. If you know you’re Rh-negative, doctors can give you a medication to prevent these antibodies from forming. This medication prevents your body from making the antibodies that could cause problems for your newborn or in future pregnancies.
In a typical pregnancy with Rh incompatibility, you’ll get two shots to prevent anti-Rh antibodies from forming: the first shot around your 28th week of pregnancy and the second shot within 72 hours of delivery.
Other situations where doctors might give you a shot to prevent these antibodies are after a miscarriage, amniocentesis, or if you have any spotting or bleeding during your pregnancy.
Do Rh-negative moms always produce Rh antibodies?
Rh antibodies are produced when and if the mom and baby’s blood mix. While typically the mother and baby’s bloods do not mix during pregnancy, it’s possible during labor and birth.
It can also happen with amniocentesis or chorionic villus sampling, bleeding during pregnancy, trauma to the abdomen during pregnancy, or trying to manually move the fetus out of the breech position.
What happens if I develop anti-Rh antibodies?
If your doctor suspects that you’ve potentially developed Rh antibodies, they’ll do an antibody screen, which is a blood test that shows if your body has made antibodies to Rh-positive blood, and, if so, how many antibodies have been made.
If you do develop these antibodies, your medical team will monitor your pregnancy and antibody levels closely to ensure that they do not get too high.