Everyone's favourite A-list mum and dad are expecting again! Blake Lively revealed she's pregnant on Thursday as she stepped out in New York to debut her growing baby bump.

She and husband Ryan Reynolds managed to keep the news a secret for several months, if Blake's belly is anything to go by.

Onlookers eruped into applause as she arrived at the 10th Annual Forbes Power Women's Summit in a tiny gold minidress on Friday.

The 35-year-old joked of her surprise: "I just like to create. Whether that's baking or storytelling or businesses or humans, I just really like creating."

This will be her and Ryan's fourth child together, the couple already sharing James, seven, Inez, five, and Betty, two.

Ryan didn't accompany Blake as she revealed the news on Thursday and was likely at home with their children, as he recently took a break from acting to spend more time with their young family.

"The biggest thing for me, and I know you have kids as well, is that I don't want to miss this time with my kids," he told LinkedIn News Senior Editor at Large Jessi Hempel last year. "For many years when my wife Blake would shoot a film, I would not shoot a film and I would be with the kids and vice versa. So we would sort of trade-off. We never really worked at the same time. But always we were away."