I watched a horror movie when I was 15 and it showed a guy reading a book in a room with bars and one of the stories was about cops going to investigate a call about something and the female cop ended up being pregnant and wakes up in a hospital bed tied down but aliens or monster people not sure what they were took her baby and put it in a jar I think, anyway if this helps at the end of the movie the guy started to get sucked in the book in the room with bars.

Necronomicon aka Necronomicon: Book of the Dead (1993)
Necronomicon: Book of Dead (1993) - IMDb (http://www.imdb.com/title/tt0107664/)

You can read the full synopsis in detail at IMDb:
Necronomicon: Book of Dead (1993) - Synopsis (http://www.imdb.com/title/tt0107664/synopsis)

You describe "Whispers", the third story the man reads from the book.

You can watch the complete film on YouTube:
H.P. Lovecraft's Necronomicon: Book of the Dead - YouTube (http://www.youtube.com/watch?v=2U_MHCL_Kq4)