Ryan Phillippe's ex-girlfriend gives birth to baby girl

Ryan Phillippe's ex-girlfriend Alexis Knapp has given birth to a baby girl named Kai.

The Lincoln Lawyer star was present in the delivery room to celebrate the birth of the child with Knapp, In Touch reports. This is the third child for Phillippe, who has two children with ex-wife Reese Witherspoon.

Phillippe is said to be unsure if he is in fact the child's father, given that the pregnancy was discovered after the couple had broken up. However, the actor remains committed to Knapp and the newborn baby girl.

"Ryan took Alexis to her last doctor's appointments and was there in the hospital when she gave birth," a friend said. "He's waiting for the DNA test to see if he's the father, but he's acting like he is."

In April, the actor said that he enjoys being a hands-on parent, stating that he believes it is important to ensure that that his children are grounded as individuals when they grow up.

Phillippe was most recently linked to actress Amanda Seyfried. The pair reportedly split in late May after they began dating earlier this year.