Blake Lively and Ryan Reynolds reveal they're expecting their third baby

Blake Lively and Ryan Reynolds are expecting their third child as the actress debuted her baby bump at a movie premiere.

This afternoon the Hollywood pair posed for photos at the New York City premiere of Pokémon Detective Pikachu.

Lively was all smiles when she showed off her bump in a sparkling yellow gown.

Reynolds also looked excited and handsome as he posed for photos with his leading lady.

The couple, who try to keep their family life private, already have two children together and have gushed about parenthood in rare interviews.

"My husband and I chose a profession and a side effect of that is your personal life is public," Lively previously told Marie Claire UK.

"Our child hasn't had the opportunity to choose whether or not she wants her personal life to be public or not. So in order to give her as much normality as possible, we want her to have a childhood like we had."

Reynolds also told E! News how both stars have embraced every twist and turn with love, humour and patience.

"There have been times where I woke up, literally had no idea I had been walking for five minutes," Reynolds previously said.

"But you love it. You wake up in the middle of the night, you got a big stupid smile on your face. I was telling someone else that. Anything else that woke you up every 45 minutes, you'd kill it. But when it's a baby, it's the best thing that ever happened to you."

This article was first published on nzherald.co.nz and is republished here with permission.