He told People magazine: “She’s always wanted to be a mother and now she’s going to be.
“I only wish her the best, I always have. I couldn’t be any happier for her. I can’t wait to see the baby.”
Jennifer married Chris, her former back-up dancer, in 2001. The pair divorced the following year.
The 38-year-old star married Marc in 2004, and there have been persistent rumours over the last month that the pair are expecting a child together.
Recent pictures of Jennifer performing live have shown her with an apparent baby bump.
Although Jennifer has refused to comment, the pregnancy was seemingly confirmed earlier this month by Marc’s ex-wife Dayanara Torres, the mother of two of his children.
She said: “I already know about the baby.
“I suppose they will be happy because when my sister had her baby they were very happy.”