at age 40, mariah was carrying twins.was a high-risk pregnancy. >> it was good news, but it was scary news at the same time. >> reporter: were you worried about carrying a child? >> i don't think i understood the enormity and the magnitude of what it really does to your body. like it's not just, oh, you don't look pretty and you have a bump. no. >> reporter: you had a very tough pregnancy. >> yeah, carrying two babies. unless somebody's been through it, it's difficult to understand what i went through because of my pregnancy was very unique in terms of what happened to me. >> reporter: the public never knew about her long periods of bed rest, false labors and several emergency trips to the hospital. what we did see was a very pregnant, very public, yet irrepressible mariah releasing a christmas album and performing for the president. but mariah says that late in her pregnancy she could barely move, barely get out of bed by herself. >> i was afraid i wasn't going to be able to walk properly again. it was a huge strain. i w