Jessica Simpson "couldn't wait" to pose naked.

The heavily-pregnant star -- who has previously struggled with her fluctuating weight -- bared all for the cover of Elle magazine and admitted she is currently feeling more confident about her body than ever.

She said: "Normally I'm hoping to be 107 pounds and I don't eat, but I ate cheesecake before we shot.

"I wasn't nervous at all, Normally, I'm so shy. I'm not the person you see photographed in a bikini on a beach. But for some reason, being pregnant, it's so easy for me. I feel so comfortable in my skin."

The 31-year-old star -- who is engaged to football star Eric Johnson -- is starting to feel "anxious" about giving birth but insists she isn't afraid of labour.

She told USA Today: "(I''m anxious) for my water to break, for the day I get to go to the hospital and push. I'm more anxious than afraid. I have not been afraid the whole time. I figure if all these women all around the world can do it, I can do it."

Jessica has been told she will deliver a big baby, but was expecting her daughter to be larger than average because of Eric's tall frame.

She said: "She's in the 90th percentile of weight right now, so she's a big one. She's going to be a very big baby, but I guess that's what I get for letting a baller knock me up."

And when the baby does arrive, she will already have a friend in Jessica's nephew Bronx Mowgli, her sister Ashlee's three-year-old son with ex-husband Pete Wentz.

She said: "Bronx talks to her in my belly all the time. It really makes your heart melt. He's already got a box of old toys he's put together for her.

"Yesterday, he said he was going to teach her how to crawl and then how to walk. It's so cute."