Determining the biological father of your child is very important. Many times people request paternity tests for legal reasons, such as child support, custody battles, or inheritance.
A legal paternity test can increase the likelihood of child support cases by proving the father is, in fact, the biological father and therefore financially responsible for the children.
Sometimes there are shocking outcomes. For one New Jersey father, DNA paternity tests proved he was only the biological father of one of the girls in a set of twins. Although rare, bipaternal twins is possible according to Dr. Keith Eddleman, who explains that an egg has a lifespan of 12 to 48 hours, and a sperm is viable for 7 to 10 days, leaving the potential for the fertilization of two eggs by two sperm from two different men.