Learning About Emergency Blood Transfusion and Future Pregnancy

An emergency blood transfusion is a treatment to replace blood when you have severe blood loss. You may need an emergency transfusion after serious injury, major surgery, or another health problem that causes too much blood loss. During the transfusion, blood flows from a bag through an intravenous (I.V.) tube and into your vein.

An emergency blood transfusion is done to help save your life. If you lose too much blood, your body can’t maintain a proper blood pressure. This lack of blood pressure causes shock. Shock means that your body and its functions are shutting down. Shock is a life-threatening problem.

The four main blood types that people have are A, B, AB, or O. Your blood is “typed” by whether certain markers, called antigens, are on the surface of red blood cells.

If your red blood cells:

• Have the A antigen, you have type A blood.
• Have the B antigen, you have type B blood.
• Have the A and B antigens, you have type AB blood.
• Do not have either the A or B antigen, you have type O blood.

Another important marker on the surface of red blood cells is the Rh factor. This is what makes a blood type positive or negative. A person whose blood contains the Rh factor is Rh-positive. A person whose blood does not have the Rh factor is Rh-negative. If a person has B-positive blood, for example, that person is Rh-positive. A person with B-negative blood is Rh-negative.

When you have lost too much blood, there may not be enough time to test your blood and get the results. So the blood you get may not match your blood type. Type O blood is often used in emergencies.

Type O-negative blood is called the “universal donor” type. This is because it is compatible with any blood type. If O-negative blood is available, it may be used in an emergency blood transfusion.

O-positive blood can also be used in an emergency. Type O-positive blood is compatible with many people’s blood types, but not all. It’s often used in emergencies because it may be more available than O-negative blood.

When you have severe blood loss, waiting to find out your blood type may be more dangerous than giving you a transfusion of type O blood right away. Once your blood type is known, you may be given the blood type that matches.

An emergency blood transfusion may affect a future pregnancy if you become Rh-sensitized.

Rh sensitization can happen if you have Rh-negative blood and are given Rh-positive blood (such as O-positive) during a transfusion. Because the blood types don’t match, your immune system may make antibodies against Rh-positive blood.

If you get pregnant with an Rh-positive baby and you are Rh-sensitized, antibodies in your blood can attack the baby’s blood cells. This can cause Rh disease.

A newborn with Rh disease has mild anemia and may have jaundice. In severe cases, anemia, jaundice, and swelling can be very dangerous or fatal. Some babies need to be delivered early. Some need special care in the neonatal intensive care unit (NICU). A very sick baby will need a blood transfusion before or after birth.

If you’re Rh-negative and you receive Rh-positive blood during a transfusion, you may get a test to check your blood for Rh antibodies. This is done with an Rh antibodies screening test or indirect Coombs test.

If Rh antibodies are found, you’ll have a follow-up visit with your doctor. You can discuss your test results and plan your next steps.

To help plan for future pregnancy, your doctor may recommend that you talk to an obstetrician and gynecologist (ob-gyn). You may also talk to a doctor who specializes in high-risk pregnancy. And you may be referred to a hematologist. This is a doctor who treats diseases of the blood.

If your blood does not have Rh-antibodies, your doctor may recommend an Rh immune globulin shot. It depends on how much Rh-positive blood you were given during the transfusion. If you got only a small amount, you may be able to get this shot. The shot can help prevent your body from making the antibodies that can cause problems during a future pregnancy.

After an emergency blood transfusion, you may want to ask your doctor some questions. They include:

• What is my risk of Rh sensitization?
• Is there anything we can do to prevent it?
• If I do get pregnant in the future, will I need to be closely watched more often?
• Are there any other things I might be able to do to have a safe pregnancy?

To learn more, you can find information on these websites:

• American College of Obstetricians and Gynecologists at acog.org/womens-health
• Allo Hope Foundation at allohopefoundation.org