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Johansson, who's expecting her first child with fiancé Romain Dauriac, plays Black Widow in the series, a character known for her form-sitting catsuits, which don't exactly leave a lot of room for a growing baby belly. Marvel plans to address Johansson's advancing pregnancy -- the star is reportedly due in August -- by adjusting her call sheet.
E! reports that Marvel will "fast-track her scenes," and that the actress "is scheduled to begin shooting 'Avengers 2' overseas on April 5, after her promotional tour for 'Captain America' is complete. The studio wouldn't comment about her having to reschedule filming."
Johansson and Dauriac got engaged last year. The actress can next be seen as Black Widow in "Captain America: The Winter Soldier," which hits theaters April 4.
"Avengers: Age of Ultron" is due out on May 1, 2015.