"We're really happy. I didn't think it was in the cards for me, I'll be honest, and so I was completely shocked," Arnold, 53, says. "It's a miracle."
Married three times prior to tying the knot with Groussman, 37, in Maui in 2009, the dad-to-be admits his fertility struggles — "I have a very low sperm count" — have played a part in all of his relationships.
"It is hard on the women," Arnold, who recently played Georgie on Sons of Anarchy, shares. "I've tried with other people, but since there is a God we were unable to conceive. Now God said, 'This is it!'"