American Pie star Jason Biggs is set to become a father - his actress wife Jenny Mollen is pregnant with the couple's first child.

The actor announced the happy news during an interview on U.S. Tv show Chelsea Lately on Wednesday (17Jul13).

He showed off a picture of his wife and crudely commented on the size of her breasts, saying, "Her breasts are very big these days. Would you like to know why? Cause I put a baby in her belly!"

The actor later retweeted a sonogram image of their unborn child, which Mollen had posted on Twitter.com.

The pair wed in April 2008 after meeting on the set of My Best Friend's Girl.