Is a person’s blood type associated with a higher or lower chance for IVF
success? What about couples with blood type incompatibility? Will that cause infertility,
miscarriage or IVF failure? I have the answers for you in today’s episode of infertility TV
First some background. Red blood cells have markers on their surface. These
markers are molecules that are made up of proteins or sugars. There are many
different blood types or blood groups. The two we will focus on today are the
ones you probably know. The ABO blood group and the Rh blood group
Your ABO blood type is determined by sugars on the surface of your red blood cells. The four
blood types are A, B, combined AB and O. Some scientific studies have suggested that people
with certain ABO blood types may have a higher or lower risk of certain diseases. For example,
people with Type O blood seem to have a lower risk of cardiovascular disease. People with
A or B blood type have a higher risk for some cancers. What about infertility? A study of over
3000 couples with infertility was published in 1969. They looked at the ABO blood types of both
partners. They did not find that any particular blood type was more or less likely to be found
in couples with infertility. They also did not find that ABO incompatibility
between the partners led to a higher chance for infertility or early pregnancy loss.
More recently, researchers looked at whether ABO blood type was associated
with IVF success. They looked at over 2300 couples who were attempting IVF
for the first time and having a single embryo transfer. Again,
no difference in pregnancy rates were identified between the different blood type groups.
The other major blood grouping is known as the Rh blood group. Like the ABO blood group,
a person’s Rh status is determined by molecules on the surface of the red blood cells. Instead of
sugar molecules as seen in the ABO grouping, Rh antigens are proteins. The Rh system is a
lot more complex than the ABO system. There are around 50 different Rh antigens. One of
the most important antigens, the D antigen, is very important during pregnancy. People with the
D antigen are referred to as Rh positive. People without it are called Rh negative.
Problems can arise if a person who is Rh negative is exposed to red cells that are Rh positive. For
example, if an Rh negative person receives a transfusion of Rh positive red blood cells,
their immune system will attack the Rh blood cells causing a serious transfusion reaction.
During a pregnancy, if an Rh negative mother has a fetus which is Rh positive because the
father was Rh positive, the mother can produce antibodies that attack the Rh positive fetus.
The first time the mother is exposed, it does not cause problems because the immune reaction is very
mild. If the mother is exposed a second time, however, it can cause a severe problem in the
fetus. The mother’s antibodies can destroy the red blood cells of the fetus causing a problem
called Hemolytic Disease of the Newborn. This is why Rh negative mothers receive a
medication called Rhogam, to help prevent the mother from making these antibodies.
Rh incompatibility is not associated with infertility. That study I talked
about earlier which examined ABO blood groups also
looked at Rh groups but again found no relationship with infertility.
Some of my patients have worried that Rh incompatibility may be responsible for early
miscarriages. This does not happen however. Fetal blood cells don’t develop immediately.
Even after they are formed, there is such a small amount of Rh antigen that it doesn't activate the
mothers immune system. Rh incompatibility is a problem only in late pregnancy.
Our Infertility TV Bottom line is this. Blood types are not associated with either infertility,
IVF success or early miscarriage. This is one less thing you have to worry about