Letterman Pacing Hospital Floor?

David Letterman had a good excuse for missing work: His girlfriend was in labor with their first child.

Bandleader Paul Shaffer filled in for Letterman as host Monday. He told the audience: "If you're feeling that there's something wrong with this picture — you're seeing me — because Dave is at the hospital waiting for his baby to be delivered!"

There was no immediate word on where Letterman, a Connecticut resident, and girlfriend Regina Lasko were, spokesman Tom Keaney said.

Letterman, an Indianapolis native, was looking forward to being a first-time dad — but admitted some trepidation.

"Here I am, 56, and by all rights it shouldn't be happening," he said on his show in September. "But, there's nothing we can do about it now. And I'm terribly excited about this. I'm scared silly about this."

Letterman spokesman Steven Rubenstein did not immediately return a call Tuesday morning seeking word on the baby.