The world is set to welcome yet another member of the Hanson clan.

Zac Hanson, the youngest of the pop-rock trio that had teens and 'tweens screeching "MMMBop" a decade ago is all set to become a father.

People magazine reports that 22 year-old Zac and his wife Kate, 23, are expecting the arrival of the eleventh Hanson clan member next May.

Zac says he's "utterly thrilled" at becoming a Daddy.

"I can't wait to meet this person." Adds Kate, 23, calling the pregnancy "the most romantic thing we've ever done."

Middle brother, Taylor, already has three children, and eldest brother Isaac, has a son.

"It will be really fun to see five little ones grow up together," says Zac.