Evan Rachel Wood shows off baby bump at Tribeca Film Festival soiree

Evan Rachel Wood is a glowing -- and growing -- mama-to-be.

The actress -- who is expecting her first child with hubby Jamie Bell -- showed off her baby bump in a gorgeous belted halter-neck dress at Vanity Fair's swanky Tribeca Film Festival opening night party on Tuesday.

Twenty-five-year-old Wood, who is a juror at this year's festival, lovingly cradled her middle for photographers and mugged for the cameras, but she wasn't excited for every aspect of the soiree, held at the State Supreme Courthouse downtown.

"I love that I am going to a cocktail party tonight, but I can't have any cocktails," Wood, who announced her pregnancy in January, tweeted before the event. "It's like a birthday with no cake."

Also on the guest list at Tuesday night's bash were festival co-founder Robert DeNiro, Whoopi Goldberg (whose directorial debut, "I Got Somethin' to Tell You," is in the fest), Christopher Walken, Mira Sorvino, Gayle King, Victor Garber and Sienna Miller.