PATERNITY CAN BE RULED OUT BASED ON BLOOD TYPE MATCHING IN MANY CASES.
ABO blood type calculator, Blood type matching - child, father and mother
ABO blood type calculator can be used to predict possibilities of paternity.
The calculator is used to determine either:
- The ABO blood type of the child/baby when the blood type of the mother and the father are known (top chart), or
- The ABO blood type of the father if the blood type of the mother and the child/baby are known (bottom chart).
ABO Blood Type Calculator:
|Father's Blood Type|
|A||A or O||A, B, AB, or O||A, B, or AB||A or O||
Blood type Must Be
|B||A, B, AB, or O||B or O||A, B, or AB||B or O|
|AB||A, B, or AB||A, B, or AB||A, B, or AB||A or B|
|O||A or O||B or O||A or B||O|
|Child's Blood Type|
|A||A, B, AB, or O||B or AB||B or AB||A, B, or O||
Blood type Must Be
|B||A or AB||A, B, AB or O||A or AB||A, B or O|
|AB||A, B, AB or O||A, B, AB, or O||A, B, or AB|
|O||A or AB||B or AB||A, B, or O|
ABO blood types can be complicated to understand. This is mostly due to the fact that the 'O-type' antigen is masked by the presence of an A- or B-type antigen. This is explained in the following chart, showing the different the genotypes that make up the blood types.
|AO or AA||A blood type|
|AB||AB blood type|
|BO or BB||B blood type|
|OO||O blood type|
For example, two O blood type parents can produce a child with only O blood type. Two parents with A blood type can produce a child with either A or O blood types. Two parents with B blood type can produce a child with either B or O blood type. One parent with A and another with B can produce a child with A, B, AB or O blood types. If one parent has A and another has AB, they can either produce a child with A, B or AB blood types. If one parent has A and another has O, they can either produce a child with A or O blood types.
Rh Positive (Rh+) and Negative (Rh-) Blood Types
The Rh (+/-) factor is inherited separately from the ABO blood types. Similarly to the masking effect of the O gene in ABO blood types, the Rh negative (Rh-) gene is also masked by the presence of a Rh positive (Rh+) genotype. Therefore, a person may have a Rh + blood type and can still have an Rh - gene (See the chart below). Furthermore, 2 parents with Rh + blood types can have a child with Rh - blood type.
|(+ , -) or (+ , +)||Rh +|
|(- , -)||Rh -|