Director Mira Nair has revealed that before she started shooting for her movie 'Vanity Fair,' she asked actress Reese Witherspoon, who plays the lead role of Becky in the movie, to get pregnant so that she would get a fuller figure.

'Vanity Fair' is the story of Becky Sharp, a poor girl growing up in 1840's London who defies her poverty-stricken background and ascends the social ladder alongside her best friend, Amelia. Written by William Thackeray, the novel was made into a film by Mira Nair, director of the award winning 'Monsoon Wedding'.

The critically acclaimed director Nair said that she had gone for dinner to Witherspoon's house before the movie started filming and she asked Witherspoon's actor husband, Ryan Philippe, to 'knock her up.'

"I am not a fan of underfed Los Angeles actresses so the year before we began filming, I had dinner at her home and told her husband to knock her up... and he did," Nair said.

"It had a wonderful effect on her luminosity and womanliness. In those days the dresses had plunging necklines. It was the bosom that I wanted and I certainly got that," she added.