The actress's announcement has meant that the shooting of Heroine is indefinitely on hold.
Murder 2 producer Mahesh Bhatt told Mumbai Mirror: "When the leading lady has to provide the glamour quotient and she [then becomes] another entity completely in the eyes of the consumer - from a desirable diva to a new mother - [it] serves as a body blow to producers."
However, Bhatt and fellow producers Ekta Kapoor and Vipul Shah argued that such a clause is not enforceable, saying that it should remain an "unspoken" agreement.
It was rumoured that the "dark" subject matter of the film may have made shooting it too stressful for the pregnant star, while speculation has also centred on whether she would be able to act out key scenes.
The pregnancy was revealed last week by her father-in-law Amitabh Bachchan, who tweeted fans with the news.