Producers behind the new X-Men movie had to make a raft of last-minute changes to Halle Berry's role to accommodate her pregnancy as filming with a growing baby bump proved to be a "constant challenge".

The actress is expecting a baby with her new husband Olivier Martinez, but she refused to let her pregnancy stop her from reprising her role as mutant Storm in upcoming blockbuster X-Men: Days of Future Past.

Berry has revealed the filming schedule was arranged to make sure her scenes were filmed early on before her bump grew too big, and the role had to change because of it.

She tells Total Film magazine, " I wasn't in (the film) as much as I was meant to be... That (the baby bump) kind of coloured what my involvement could be, which was why I was one of the first ones in and the first ones out. My ever-growing belly was posing a constant challenge! What I could do was getting more limited so the role that I play is so different from what it could have been, due to my surprise pregnancy."

The star's baby is due later this summer (13). She also has a five-year-old daughter, Nahla, with her former partner Gabriel Aubry.