If you are planning to become pregnant, it’s a good idea to talk to your doctor about a blood test to determine your Rh factor. This is a good move for both yourself and your partner. While very rare, complications related to Rh factor can be serious, so it doesn’t hurt to get as informed as possible about your risks.
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what is Rh factor?
Rhesus (Rh) factor refers to whether or not your red blood cells have a certain protein. If they do, you are Rh positive, and if they don’t, you are Rh negative. Two Rh positive parents will have an Rh positive child, while two Rh negative parents will have an Rh negative child. About 85% of people are Rh positive.
It’s not “better” or “worse” to be one or the other, but pregnancy complications can occur when the mother is Rh negative and the father is Rh positive, because the baby may be Rh positive like his father.
- The Rh factor is a protein found on the surface of red blood cells.
- If a person has the Rh factor, it is said to be Rh-positive. If a person does not have the Rh factor, it is said to be Rh-negative.
- A pregnant woman who is Rh-negative can develop antibodies to the Rh factor.
- If these antibodies cross the placenta and enter the blood of the fetus, they can destroy the fetus’s red blood cells, a condition called hemolytic disease of the newborn (or HDN).
- HDN can be mild, causing only a decrease in the number of red blood cells (anemia). In its most severe form, HDN can cause heart failure and death of the fetus.
- Rh-negative women who are pregnant or who have been pregnant in the past should be tested for the presence of Rh antibodies. If they are present, the woman will be given a series of injections of a blood product called Rho(D) immune globulin (RhoGAM) during her pregnancy to prevent the development of these antibodies.
Rh-Negative Factor and Pregnancy
When an Rh-negative woman gets pregnant, there is often a risk of sensitization. This is when the immune system creates antibodies to fight off a foreign substance, in this case, the baby. The Rh-negative woman’s body may think the fetus is a foreign substance and create antibodies against it. This can be very dangerous for both the fetus and the mother. If sensitization occurs, the mother’s body will create antibodies to fight the fetus. The problem is these antibodies can cross the placenta and attack the baby, resulting in severe health issues like anemia, jaundice, and brain damage. If you are Rh-negative and unaware of your blood type, this can cause problems during the first and second trimesters.
- The Rh-negative factor can cause problems during pregnancy.
- If a pregnant woman has Rh-negative blood and her fetus has Rh-positive blood, the woman’s body may produce antibodies to the fetus’s blood.
- These antibodies can cross the placenta and enter the fetal bloodstream, causing hemolytic disease of the newborn.
- Symptoms of hemolytic disease include anemia, jaundice, and enlargement of the liver and spleen.
- In severe cases, it can lead to heart failure and death.
- If you are Rh-negative and become pregnant, you will need to have special blood tests and receive treatment to prevent complications.
Rh-Positive Factor and Pregnancy
If you are Rh-positive, your blood type poses no threat to the fetus. This is because your body creates antibodies against foreign substances, making it less likely that you will produce antibodies against your own fetus. If you are Rh-positive and become pregnant with an Rh-negative fetus (which is more common), the fetus will have Rh antibodies in its blood stream. The antibodies will cross the placenta and collect in your blood stream. This generally has no adverse effects; however, there is a chance that the Rh antibodies could trigger a reaction in your body. If this happens, your body will form antibodies against the fetus, which could result in serious complications and even death.
- Rh-positive blood is compatible with all blood types, making it the safest blood to give in transfusions.
- Rh-positive blood is also the most common blood type, so it is more likely to be available in emergency situations.
- Rh-positive blood is less likely to cause an allergic reaction in the recipient.
- Rh-positive blood is less likely to cause complications during pregnancy.
RH Factor, Pregnancy, and Birth Defects
If an Rh-negative woman becomes pregnant with an Rh-negative fetus, there is no need to be concerned. However, if she becomes pregnant with an Rh-positive fetus, complications can arise. For a Rh-negative woman to protect the fetus, she needs to receive regular doses of Rhogam injections. If she fails to receive these shots, she can develop Rh antibodies. Her body will form an extra layer of antibodies that attack the fetus. If this occurs, the mother will suffer from a condition called Rh Disease. You may experience increased blood loss, fever, pain, and swelling.
Why is that a problem?
Mama and baby have separate circulatory systems, so their blood is unlikely to mix except during childbirth or with certain tests or complications/trauma in utero. However, if an Rh negative mama is exposed to her Rh positive baby’s blood, mama’s immune system interprets that Rh positive blood as a threat. As is the function of our immune systems, hers will try to destroy the threat. This, of course, is dangerous to baby.
How does Rh factor affect second pregnancies and beyond?
If your first baby is Rh negative, there is no danger. However, if your first baby is Rh positive while you are negative, it’s very possible his blood has mixed with yours during childbirth, whether vaginal or C-section. (This is also true if your first pregnancy was ectopic or if you had a miscarriage or termination.) In response, your body has produced antibodies to Rh positive protein. The next time you are pregnant, an Rh positive baby is vulnerable to your antibodies.
What actions should I take if I am Rh negative?
Again, if your partner is also Rh negative, there is no issue. Your doctor will prescribe an antibody screen to check whether your blood has already produced antibodies to the Rh positive protein. If not, at around 28 weeks of pregnancy, you will be given a dose of RhIg (Rh immunoglobulin) to prevent those antibodies from forming. It will be administered again within 72 hours after birth.
What if I do have antibodies?
If you have antibodies, RhIg will not help. In this case, your doctor will watch your pregnancy carefully and test baby for signs of anemia or hemolytic disease. If the anemia is mild, baby is likely to born near his due date, with no need for early inducement. If it is more severe, a blood transfusion can be done in utero (through the umbilical cord) and after birth to replace his blood.
Conclusion
When it comes to Rh factor and pregnancy, there are many misconceptions. When Rh-negative women become pregnant with an Rh-positive fetus, they must receive Rhogam injections to prevent complications. If you are Rh-negative and unknowingly become pregnant with an Rh-positive fetus, complications can arise. If you are Rh-negative and interested in getting pregnant, you must ensure that you are with an Rh-negative partner. If not, there are ways to protect the fetus from Rh antibodies. In the end, you must be aware of your blood type to protect your health and the health of your future child.
