Jessica Alba dresses as teen movie mom Juno for Halloween

Jessica Alba used her growing baby belly as part of her costume for singer pal Kelly Rowland's Halloween party over the weekend.

The actress, who recently announced she and her husband Cash Warren are expecting their first son - a sibling for daughters Honor, nine, and Haven, six - embraced her pregnancy and teamed up with pal Kelly Sawyer to recreate the characters played by Ellen Page and Michael Cera in 2007 film Juno, about an independent-minded teenager who finds herself with child.

Copying Page's look in the poster for the movie, Jessica wore jeans, a hoodie, a red and white striped hoodie, and sneakers, while her friend posed as Cera's Paulie Bleeker, in a pair of yellow shorts, a red T-shirt, trainers, and yellow sweatband around her head.

Jessica captioned a snap she posted of the pair online, "#juno #happyhalloween@kellysawyer and I."

The fun photo racked up nearly 200,000 'likes' in a couple of hours and won Jessica praise from fans, with one commenting: "Such an awesome costume idea," and another adding: "Ah ah ah fantastic, I love you, this movie is sooo epic !!!!"

Alba wasn't the only celebrity incorporating a real-life baby bump into their Halloween costume for the star-studded party - Kevin Hart's wife Eniko Parrish, who is due to give birth to the couple's first child shortly, recreated the outfit then-pregnant Ciara wore to the Vanity Fair Oscar Party in February, while model Behati Prinsloo, who is expecting her second child with husband Adam Levine, opted to wear a black suit printed with a skeleton and a baby skeleton over her stomach.

Rowland's Costume Couture Party at Poppy in Los Angeles on Sunday night (29Oct17) also brought out Jay-Z and Beyonce as late rapper Notorious B.I.G. and his girlfriend Lil' Kim, while Usher dressed up as Rick James and Tyler Perry channeled Run-DMC.

Meanwhile, on Saturday night (28Oct17), stars like Miles Teller, Ariel Winter, and Will Poulter were among the guests at Matthew Morrison's eight annual Halloween party in West Hollywood.