Dear doctor,

My blood group is O. I hear I cannot get pregnant even if I have unprotected sex. Is this true?

Catherine, Form 3

Dear Catherine,

A woman’s blood group has no bearing on fertility. Recently some studies showed that women with blood group O have a lower number of eggs and reduced fertility but it does not say that they are infertile. As per the researchers, it is too early to recommend women with blood group O to seek early treatment for fertility.

The problem with blood groups comes when the Rhesus (Rh) subgroup of the pregnant woman and fetus are different. Rh is a protein present on the surface of the red blood cell. It may be present (+ve) or absent (-ve).

When a pregnant mother and baby in a womb have different Rh types, antibodies are formed in the mother’s blood against the baby’s blood. This leads to severe break down of blood cells of the fetus which can harm both mother and baby. One is more susceptible to it in second and subsequent pregnancies. Injection of immune globulins in early pregnancy prevents this.

Dr Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital