Fox and Pollan Have Baby on Board

Michael J. Fox and wife Tracy Pollan are expecting their fourth child, the actor has announced.

"We just kind of looked around and figured there was just someone who wasn't there yet," Fox quipped to TV Guide. "Someone who was supposed to show up to the party. So we thought we'd issue an invite."

Fox — who celebrates his 40th birthday this weekend — has three children with Pollan: Sam Michael and twins Aquinnah Kathleen and Schuyler Frances. The couple married in 1988 after playing lovebirds on the '80s sitcom Family Ties.

Fox may be heading back to ABC for a guest spot on his former hit show, Spin City, next fall. The star, who has Parkinson's disease, departed from the series in May 2000 in order to battle his illness.