If I may make a suggestion; if the medical droids are re-dubbed could you not do something akin to Bingowings suggestion; have the medical droids say something like;

"As you are aware she is force sensitive, something or someone is slowly draining the force from her. Because of this she is very weak and needs to give birth as soon as possible. This draining effect means she won't heal from the injuries she has sustained; it is predicted she only has a few years to left to live."

I don't think we need all the exposition, especially if cut to Vader, I think the above is enough to make a connection between Anakin living and Padme dying. I would vote against Padme dying in the film given what Leia says in Jedi; could Organa's dialogue be slightly tweaked so he says "We will take Padme to Alderaan she'll be safe there" or whatever it is he exactly says?