Pregnant Miranda Kerr gets naked for W mag

Guess we have Demi Moore to thank for this?

Miranda Kerr has passed another Hollywood Mommy-to-Be milestone with what seems to be the now-obligatory preggers 'n' nekkid photo.

So what prompted the supermodel to bare all?

PHOTOS: Baby Bumpin'

Mrs. Orlando Bloom stripped down as part of W magazine 's family issue.

The glossy's December installment, which hits newsstands Wednesday, also features Usher and sons Usher V and Naviyd, Madonna and Lourdes, Katherine Heigl and Naleigh, and Jenna Jameson and her twins — yes, her actual sons, Jesse and Journey, not just her chest.

PHOTOS: Famous Families