Johansson’s pregnancy while filming “Avengers: Age of Ultron”, came with a few interesting coincidences. Johansson did all of her scenes first for the movie. And since playing Black Widow comes with plenty of stunts, she ended every day exhausted, eventually giving way to a stunt double.
Johansson would later appear in the Coen Brothers’ film “Hail, Caesar!” where she played an actress who got pregnant during a film. “Age of Ultron” also contains details about Black Widow, showing us snatches of her intense training, and revealing that she is unable to get pregnant, due to the experiments that she went through long before she joined the Avengers.
Blake Lively — The Shallows / The Age of Adaline
Twice now Blake Lively had been pregnant while filming a movie. The first was "The Shallows", a thriller where she played a surfer having to fight off a shark. The movie involved plenty of stunts and had Lively in a bikini almost the entire time. Only during the final weeks of the shoot did the movie start to use a stunt-double, getting by on specific camera angles, and hiding the growth that Lively was presenting.
The second film was "The Age of Adaline", which had Lively in fancy clothing that helped to hide her baby bump. She filmed almost all the way up until her due date, and didn't even ask for any special treatment while doing so.
Drew Barrymore — Blended
It was only days after Drew Barrymore signed her contract for the film "Blended" when she found out she was pregnant with her second child. While filming was expected to start soon, production delays meant that Barrymore's pregnancy had already developed. It would have been clear that Barrymore was expecting when her character was nothing of the sort.
The costume department got to work, putting in extra time that both looked great, and helped to hide Barrymore's growing abdomen. While it isn't too difficult to tell Barrymore is carrying a little extra weight, it's easy enough to ignore.
Emily Blunt — The Girl on the Train / Into the Woods
Emily Blunt has been pregnant twice while playing characters that are unable to have children. The first time was "The Girl on the Train", and filming took place early enough to not be a big problem.
The second time was "Into the Woods", and this was a little harder to hide. However, with a few costumes and a little choreography, it worked out. Blunt's character is a baker's wife, and she said that the extra weight she carried made sense since she'd probably be eating a lot of carbs around her husband.
Penelope Cruz — Pirates of the Caribbean: On Stranger Tides
Never has a sister been handier than when Penelope Cruz was filming "Pirates of the Caribbean: On Stranger Tides". The Spanish star was pregnant with her and Javier Bardem's first child during filming, but you'd be forgiven for not knowing that. During the swashbuckling action scenes, Penelope tagged in an actress friend of hers: her younger sister Monica.
Penelope did as much as she could while staying safe and then ceded the action scenes to Monica, who's also a dancer. The two sisters have more than the usual amount of family resemblance, and it was a perfect way to make filming this adventurous movie easier.