I slept my last two on their tummy's and should have slept my first born too.
IMHO the bottom line is babies are more secure on their tummys, on their backs their arms flail w/ the morrow relflex and startle them awake. Swaddling, or sleepign on side with positioners are two options. I slept my last two tummy down during naps b/c I could check on them frequentlky then swaddled on side at night.
My understanding is that the data connecting the "back to sleep" and reduction in SIDS is inconclusive. There are many other factors that need to be considered. When I disucussed it with my pediatrician she said that the biggest risk for SIDS was: Male, underweight at birth, african american, smoker in the home. As we haven't met most of those (except the male) that helped me feel at ease. I make sure they are ONLY on the mattress with a sheet on top and no pillows or comforers/ blakets are near their face. (ds often naps in our bed)
I will say my younger two are my good sleepers, I really think there is something much more secure about sleeping on your tummy.
