'Grey's Anatomy' star Kevin McKidd introduces son Aiden

May 14 (UPI) -- Grey's Anatomy star Kevin McKidd is a dad of three.

The 44-year-old actor introduced son Aiden in an Instagram post Sunday after welcoming the infant with wife Arielle Goldrath.

The black and white photo shows Goldrath sharing a sweet moment with a sleeping Aiden. McKidd is also parent to 18-year-old son Joseph and 16-year-old daughter Iona with ex-wife Jane Parker.

"On this beautiful Mother's Day evening... Welcome- little Aiden to our family and to the World!" he wrote. "Arielle, you're the most amazing mother and I love you both so much! #happymothersday #forever #weeAiden #Arielle #newlife."

McKidd's co-star Sarah Drew was among those to comment on the post.

"I can't wait to snuggle him again!!! He's so beautiful!!" the actress gushed.

McKidd had announced his marriage to Goldrath and her pregnancy in a post on his website in March.

"Arielle and I are so happy to announce our marriage a new baby, who is soon to join our growing family. Close friends and family came together with my Grey's family to share in our celebration day," he wrote.

McKidd plays Owen Hunt on Grey's Anatomy. Drew, who portrays April Kepner, defended co-star Kelly McCreary last week after McCreary's character, Maggie Pierce, developed a romance with April's ex-husband, Jackson Avery (Jesse Williams).