Elizabeth Banks wouldn't classify co-star Cameron Diaz "as a regular human being."

The 38-year-old actress stars alongside Cameron and Jennifer Lopez in upcoming romantic comedy What to Expect When You're Expecting.

Although some of the hottest women in Hollywood are having babies in the film, Elizabeth ensures that nearly everything about the plot is normal.

"I wish it went sci-fi. It would be so cool if I got a unicorn instead of a baby," Elizabeth told Entertainment Weekly. "But no, this is about regular human beings. If you count Cameron Diaz as a regular human being. I mean, if you've seen those abs."

Elizabeth portrays an infertile woman. The star has sympathy for parents who are struggling to have children.

"I was familiar with infertility, as I think many women my age are, so I went into it with a good understanding of this character and what she'd been through," Elizabeth shared. "I really related to the idea that pregnancy is not the be-all, end-all. At the end of the day it's really about those mini human beings."

What to Expect When You're Expecting will be released in US theatres May 18.