While introducing the movie, director Robert Weide quipped that it would be great publicity if Anderson went into labor during the premiere. The actress, who is pregnant with her third child, responded by pretending to slug the director, losing her balance and hitting the floor in the process, People.com said.
Weide quickly reassured the audience Anderson was not injured in the fall and joked, "Is there a lawyer in the house?"
Anderson is best known for her roles in the "X-Files" TV show and films.
Notable deaths of 2014 [PHOTOS]
Kelly Ripa's penthouse sells for $20M