For generations, Pennsylvania law followed a simple rule: if a child was born to a married woman, her husband was presumed to be the father -- no questions asked, even when biology suggested otherwise… this is what is called the “presumption of paternity.”

The Supreme Court of Pennsylvania, however, has signaled that the answer may be changing. After decades of treating the presumption of paternity as virtually untouchable when a marriage was intact, the court has opened the door to challenges that were once automatically dismissed.

A case in point is Lyons v. Arpin & Arpin, involving an affair and a disputed biological father. Danielle Arpin was married to Michael Arpin but began a relationship with a man named John Lyons during a period when the couple was separated. Danielle later discovered she was pregnant.

There was no chance that the child was Michael Arpin’s. He had undergone a vasectomy years earlier, and both Danielle and Michael testified that they had not had sexual relations around the time the child was conceived. However, by the time the baby was born, Danielle and her husband had reconciled, and Michael accepted the child as his own.

John Lyons went to court seeking genetic testing to establish that he was the child’s biological father. Under longstanding Pennsylvania law, his request was denied. Both the trial court and the Superior Court of Pennsylvania ruled that the presumption of paternity barred him from even pursuing DNA testing. Lyons then appealed to the Supreme Court of Pennsylvania. In a dramatic turn of events while his appeal was pending, the legal landscape shifted, due to a ruling in another case.

In Sitler v. Jones, a similar scenario had played out: a married woman gave birth to a child while still living with her husband, but another man claimed he might be the biological father and sought genetic testing. Lower courts had rejected the request under the traditional rule that the presumption could not be challenged when a marriage remained intact. The Supreme Court of Pennsylvania, however, disagreed with that framework.

In this significant decision, the court held that the presumption should no longer operate as an automatic bar to challenges from a potential biological father. Instead, courts must take a more flexible approach that considers whether there is a reasonable possibility a man could be the biological father and whether determining the truth would serve the best interests of the child.

This ruling in Sitler v. Jones then had immediate consequences for is Lyons v. Arpin & Arpin. Because the lower courts had decided his case under the old, stricter rule, the Supreme Court of Pennsylvania, instead of hearing the Lyons appeal, sent the matter back to trial court to be reconsidered under the new standard. Further proceedings in the Crawford County Court of Common Pleas are pending.

While this ruling does not indicate that every individual alleging to be a biological father will be allowed to challenge paternity, nor does it mean courts will disregard existing family relationships, it does signify that a substantial change in how courts will view paternity cases going forward is imminent.

If you are facing a complicated paternity situation -- whether as a parent, spouse, or potential biological father – it’s important to understand your legal rights and arm yourself with the right representation. Contact Williams Family Law at 215-340-2207 or via email at info@bucksfamilylawyers.com.