Evaluation of the relationship between maternal blood groups and adverse pregnancy complications in women referred to the maternity ward of Ali Ebn –e Abi Taleb Hospital from April ۲۰۱۷ to April ۲۰۱۹

It is a method for dividing blood groups based on the presence or absence of certain inherited antigens on the surface of red blood cells (۱). Negative is divided. Every human being naturally has one of these four blood groups. For example, a person with blood type A expresses antigen A on his red blood cells and makes antibodies against other blood type (B) antigens in his body. A person with blood type B has B antigen. A person with blood type AB has both antigens A and B, and a person with blood type O has neither of the two antigens, and antibodies are made against both of them in the body. Researchers also say that blood type o negative is due to stronger blood cells transmitting the virus to The body prevents and has rare blood types in the world, but in general, most people in the world have blood type O (۲).In ۱۹۰۱, the Austrian immunologist Karl Landsteiner first demonstrated the presence of blood group antigens on red blood cells as well as antibodies against the same antigens in the human serum. He found that the chemical composition of blood varies from person to person. Landsteiner first isolated red blood cells from the serum and then studied the results of mixing serum and red blood cells from different people. He found that the sera of some people were able to agglutinate the red blood cells of others, but not all of them, although Landsteiner's discovery of human blood groups identified the most important ABO blood group system. It took decades of research for scientists to detect more antigens on the surface of red blood cells, so that today more than ۴۰۰ blood group antigens are detected on the surface of red blood cells, which in total are classified into more than ۲۰ different groups or systems. (۳)