TED Talk Hans Rosling: Let my dataset change your mindset:
Religion has very little to do with the number of babies per woman. All the religions in the world are fully [able] to maintain their values and adapt to this new world. </quote>
http://www.ted.com/talks/lang/en/hans_rosling_at_state.html
Yes religions can adapt, but of course they don't want to and needn't, so Rosling's reasoning isn't convincing. Utah has the highest birth rate in the US. I doubt that has very little to do with Mormonism.
Religion has very little to do with the number of babies per woman. All the religions in the world are fully [able] to maintain their values and adapt to this new world. </quote> http://www.ted.com/talks/lang/en/hans_rosling_at_state.html