Women who know they are Rh negative often wonder if their Rh status played a role in their miscarriage.
What Rh factor?
How does it affect a woman’s chances of pregnancy loss.
What is the Rh factor?
Just as there are different major blood groups, such as type A and type B, there also is an Rh factor. The Rh factor is a protein that can be present on the surface of red blood cells. Most people have the Rh factor—they are Rh positive. Others do not have the Rh factor—they are Rh negative.
Note: You can either be negative or postive, if you don’t know which you, are, please do go for a sure test.
The Rh factor is inherited—passed down through parents’ genes to their children. If the mother is Rh negative and the father is Rh positive, the fetus can inherit the Rh gene from the father and could be either Rh positive or Rh negative. If the mother and father are both Rh negative, the baby also will be Rh negative.
The Rh factor can cause problems if you are Rh negative and your fetus is Rh positive. This is called Rh incompatibility. These problems usually do not occur in a first pregnancy, but they can occur in a later pregnancy.
When an Rh-negative mother’s blood comes into contact with blood from her Rh-positive fetus, it causes the Rh-negative mother to make antibodies against the Rh factor. These antibodies attack the Rh factor as if it were a harmful substance. A person with Rh-negative blood who makes Rh antibodies is called “Rh sensitized.”
During pregnancy, the woman and fetus do not share blood systems. However, a small amount of blood from the fetus can cross the placenta into the woman’s system. This sometimes may happen during pregnancy, labor, and birth. It also can occur if an Rh-negative woman has had any of the following during pregnancy:
During an Rh-negative woman’s first pregnancy with an Rh-positive fetus, serious problems usually do not occur because the baby often is born before the woman’s body develops many antibodies. If preventive treatment is not given during the first pregnancy and the woman later becomes pregnant with an Rh-positive fetus, the baby is at risk of Rh disease.
It also is possible to develop antibodies after a miscarriage, an ectopic pregnancy, or an induced abortion. If an Rh-negative woman becomes pregnant after one of these events, she does not receive treatment, and the fetus is Rh positive, the fetus may be at risk of Rh-related problems.
Problems during pregnancy can occur when Rh antibodies from an Rh-sensitized woman cross the placenta and attack the blood of an Rh-positive fetus. The Rh antibodies destroy some of the fetal red blood cells. This causes hemolytic anemia, where red blood cells are destroyed faster than the body can replace them.
Red blood cells carry oxygen to all parts of the body. Without enough red blood cells, the fetus will not get enough oxygen. Hemolytic anemia can lead to serious illness. Severe hemolytic anemia may even be fatal to the fetus.
A blood test, called an antibody screen, can show if you have developed antibodies to Rh-positive blood and how many antibodies have been made. If you are Rh negative and there is a possibility that your baby is Rh positive, your health care provider may request this test during your first trimester and again during week 28 of pregnancy.
Yes. If you are Rh negative, you will be given a shot of Rh immunoglobulin (RhIg). RhIg is made from donated blood. When given to a nonsensitized Rh-negative person, it targets any Rh-positive cells in the bloodstream and prevents the production of Rh antibodies. When given to an Rh-negative woman who has not yet made antibodies against the Rh factor, RhIg can prevent fetal hemolytic anemia in a later pregnancy.
RhIg is not helpful if you are already Rh sensitized.
RhIg is given to Rh-negative women in the following situations:
If you are Rh sensitized, you will be monitored during pregnancy to check the condition of your fetus. If tests show that your baby has severe anemia, it may be necessary to deliver your baby early (before 37 weeks of pregnancy) or give a blood transfusion while your baby is still in your uterus (through the umbilical cord). If the anemia is mild, your baby may be delivered at the normal time. After delivery, your baby may need a transfusion to replace the blood cells.
The Link Between Rh and Miscarriage
It’s normal to want to understand why a miscarriage happened, and it’s frustrating that definitive answers are few and far between. After hearing about the need for RhoGAM after a miscarriage, many Rh negative women wonder whether that blood type might play a role in causing the miscarriages.
The short answer to that is no, being Rh negative in and of itself does not cause miscarriage or pregnancy loss. Women who are Rh negative, who have kept up to date with recommended RhoGAM shots and who do not have antibodies against Rh factor do not face increased risk for pregnancy loss due to having Rh negative blood.
Rh Factor and Stillbirth
Assuming a woman does become sensitized to Rh factor, however, the primary risk is not of pregnancy loss but of Rh incompatibility issues with any future baby to whom she gives birth.
In Rh-negative moms who are sensitized to Rh factor, there’s also an increased risk of stillbirth due to a condition called immune hydrops fetalis that can develop in the second and third trimesters — but this condition is not a factor in first-trimester miscarriages.
The most common cause of first-trimester miscarriages is chromosomal abnormalities in the baby.
If you are Rh negative and concerned that you might be sensitized to Rh factor, talk to your doctor about having a blood test done to check for anti-Rh antibodies. If the test comes back negative, then your Rh status will not bring any increased risks in a future pregnancy (but do continue to get RhoGAM shots per your doctor’s recommendations).
Mothers who are sensitized to Rh factor should be vigilant about seeking prenatal care in any subsequent pregnancy.
While knowing that you’ve tested Rh negative may cause you to worry, especially if you’ve had a miscarriage, remember that miscarriages are incredibly common, and most women who’ve endured them are Rh positive, as is the general population. Moreover, many women who are Rh negative have gone on to have full-term pregnancies and healthy children.
Talk to your doctor about your concerns over your Rh status as well as any other factors that could have potentially led to your pregnancy loss.
Type O-negative blood is called the universal donor type because it is compatible with any blood type. These donors are considered “universal” because their blood can theoretically be given to recipients with any ABO type (A, B, AB, or O), and because they are Rh-negative, their blood can be given to either Rh-negative or Rh-positive patients.
Type AB-positive blood is called the universal recipient type because a person who has it can receive blood of any type.
A.D.A.M. “Rh incompatibility.” About.com A.D.A.M. Healthcare Center 18 Aug 2006. Accessed 27 Nov 2007.