12/10/2010 01:36 pm ET Updated May 25, 2011

Jillian Michaels Leaving 'Biggest Loser,' Wants Kids

Jillian Michaels announced on Twitter Tuesday that she will be leaving the hit show, 'The Biggest Loser,' after this season, and on Wednesday, she gave the surprising reason why.

"Season 11 of Biggest Loser will be my last :) have to finish out my contract," she tweeted Tuesday, adding the next day that, "I want to take a year off TV and focus on becoming a mommy and doing more charity work."

In April, Michaels swore off pregnancy.

"I'm going to adopt. I can't handle doing that to my body," she told the Women's Health Magazine. "Also, when you rescue something, it's like rescuing a part of yourself."

She also tweeted on Wednesday that, "Shooting 'Losing It' also had big impact on me. Living with kids I saw first hand what I was missing."

Still, she has her reservations: one more Wednesday tweet revealed, "I haven't even met this little person & I'm already talking about my fear of messing them up in therapy."