Rose Byrne expecting first child?

Los Angeles: Actress Rose Byrne has sparked rumours she pregnant with her first child after she stepped out sporting what appeared to be a baby bump underneath her loose-fitted plaid shift dress.

The 36-year-old actress is dating actor Bobby Cannavale, 45.

It is speculated the couple, who have been dating for three years after they met on the set of "Annie" reboot in 2012, are getting ready for their new family as they snapped up a three-bedroom house in Brooklyn, New York for an estimated USD 2.2 million earlier this month, reported Us magazine.

The "Bridesmaids" actress has nothing but kind words about her beau and recently admitted she feels incredibly "lucky" to share her life with him.

"He's this very kind-hearted, wonderful guy. I'm very lucky to have met him," she said.

The pair star together in both "Spy" and "Adult Beginners"

Prior to dating Cannavale, Byrne dated fellow Australian actor Brendan Cowell for six years until they split in early 2010