Natalie has slept on her stomach from the get-go; the only time she didn't was for a brief period when we tried swaddling her. (NEVER seen a baby who hated swaddling so much
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I agree - it's a personal decision. Years ago, moms were encouraged to put babies to sleep on their bellies so they didn't choke on spitup. Now people are discovering that the more time babies spend on their tummies, the better their upper body strength is, as well as some other developmental skills, so the tide is turning once again.
For us, we read up on all viewpoints, we made our decision, and for us it's worked. Good luck with whatever YOU decide!