Rh Negative Blood

Rh Negative Blood


Rh negative (Rh-) blood means that a person does not have a protein on the surface of their red blood cells. If you have the protein, you are Rh positive (Rh+). Your doctor will test you during pregnancy for this. Tell your doctor if you know you have Rh negative blood.


What you need to know

If you have Rh negative blood and the baby's father has Rh positive blood, you might need special care as your baby can have either Rh negative blood or Rh positive blood.

  • If you have Rh negative blood and your baby has Rh positive blood, you will need treatment to protect your baby's health. Without treatment, your body may make antibodies that may harm your baby.
  • There are no risks to a baby's health if the mother's and father's blood are both Rh positive blood or both Rh negative blood.

There are no risks to the baby's health if the mother has Rh positive blood.




If you have Rh negative blood, you will be given a medicine called Rho (D) immune globulin, known by brand names such as Rhophylac or Rhogam, as a shot or injection. This medicine will prevent Rh antibodies from forming that could harm your baby. This is a safe medicine for you and your baby. You will need to have your blood drawn and checked within 3 days of getting this medicine.

This medicine may also be given if your baby's blood test after birth is Rh+. You will be given Rho (D) immune globin within the first 3 days after your baby's birth.

Talk with your doctor before you become pregnant again.


© 2009 – July 25, 2019, The Ohio State University Wexner Medical Center.

This handout is for informational purposes only. Talk with your doctor or healthcare team if you have any questions about your care. For more health information, call the Library for Health Information at 614-293-3707 or email: health-info@osu.edu.