Scarlett Johansson and Romain Dauriac
Scarlett Johansson welcomed daughter, Rose Dorothy with Romain Dauriac, back in September 2014.Reuters

American actress/model Scarlett Johansson talked about motherhood while appearing on the cover of W magazine's March 2015 issue.

The 30-year-old actress described the first time she saw her daughter Rose Dorothy, whom she welcomed with husband, French journalist Romain Dauriac, back in September 2014.

"When she came out of me I was so surprised," Johansson said. "I had a very strong picture in my mind of what my baby would look like, and, of course, she is completely different. Perfect, but not what I'd imagined."

The Captain America star, who was voted Sexiest Woman Alive in 2006 and 2013 by Esquire magazine, also talked about her curves.

"Everyone has seen my breasts!" she exclaimed. "I can change my top right here."

Johansson had gone completely nude in her 2013 film Under the Skin.

"I was completely naked in that movie," she said. "She was a totally different species, so her nudity was kind of practical. I also had black hair. That was my idea—I didn't think I should be a blonde sort of bombshell. Naked, but not too sexy."

Johansson, who will be soon seen on the big screen in The Avengers: Age of Ultron, also talked about her trademark husky voice.

"When I was young, I would talk and everyone thought I had a cold. But when I went out for films, they loved my voice. It was a different world," she said.