In Wisconsin, if a child is born during a marriage, the husband is presumed to be the father. But what happens in situations where, for example, the parties have been separated for several months while your divorce is pending, and the wife becomes pregnant with someone else’s child. Can the presumption be overcome?

The answer is: not automatically. If your divorce has not been finalized, the child is considered “born to the marriage,” and is presumed to be the husband’s.

This is why the wife is asked during divorce proceedings, “are you currently pregnant?” If she is, the court will usually not grant the divorce. The idea behind this is that the child is entitled to a legal father who shall be responsible (financially, if not otherwise) for the child. Therefore, the court is highly reluctant to make a ruling that would leave the child without a legal father.

Husbands who are the legal fathers have notoriously found this presumption to be unfair, with the argument being that the presumption takes away the father’s due process rights. The Supreme Court of the United States addressed this argument over 20 years ago and found that the presumption that the mother’s husband is the child’s father does not, in fact, violate a father’s due process rights.

The presumption may be overcome, however, if another man who is biological father, even though not yet the legal father takes a genetic test, and the results show a statistical probability of that man’s parentage as 99.0% or higher. If this turns out to be the case, the court will likely order the wife to commence a paternity action against the biological father. Once paternity is established, the presumption against the husband can be overcome and the divorce can be granted.

Therefore, in situations where a child is born of the marriage but is not the husband’s biological child, it is wise for the wife, or her attorney, to commence a paternity action against the biological father immediately. In the alternative, if the wife is arguing that the child is, in fact, the husband’s child biologically, the husband or his attorney can ask the court to order genetic testing, if the husband has a doubt.

Please note, in most cases where paternity of the child is at issue in a marriage, the court appoints a Guardian ad Litem for the best interests of the minor child. The Guardian ad Litem will make recommendations for the best interests of the child, such as requiring the husband and alleged biological father to undergo genetic testing that will work towards figuring out who the biological father of the child is, and who will be found to be the legal father of the child.