Comparison of blood types among mother, child, and a man suspected of fathering the child in an effort to determine the father. If the child’s blood group could not have resulted from the combination of the man’s blood group with that of the woman, then the man is definitely not the father of the child. However, other results are not conclusive, since a finding that the man could be the father does not prove that he is the father.
A test to determine the father of a child. Because paternity is a clinical estimate, there is the need to have tests to determine whether it would be possible for an individual to have fathered a specific child. At one time, the tests used to prove or exclude the possibility of paternity used blood type data from the child and the suspected father. Tests involving the technique of molecular genetic fingerprinting and of determining genetic markers are available and have the ability to exclude almost all except the father. Use of these techniques makes it possible to distinguish differences between the genotype of all individuals except identical twins.