In Florida six women are challenging a law that requires women who don't know who fathered their children to publish details about their sexual partners in local newspapers if the child is to be adopted, reports The Guardian.

The purpose of the law is to allow birth fathers the opportunity to contest the adoption if the mother can't trace him or isn't aware of his name.

The ad contains details of their sexual partners around the time of conception including distinguishing characteristics of possible fathers. The ad must appear for four consecutive weeks.

The legislation emerged after the Florida case of a child born in 1992 and later adopted by a couple who had to fight a court battle to keep her after the absent biological father contested the adoption.