This article is from the Sudden Infant Death Syndrome FAQ, by David Stokes firstname.lastname@example.org and Margaret D. Gibbs gibbsm@no_spam.poppyware.com with numerous contributions by others.
The American Association of Pediatrics recommended in 1997 that
infants be placed on their back, as studies have shown this has
reduced the rate of SIDS in some areas. Death from aspiration
of vomit is much rarer than SIDS. Not all doctors are convinced,
and babies have died of SIDS while sleeping on their side or
back. There are a few exceptions for the back recommendation:
if the baby has reflux, or certain upper airway malformations
such as Robin Syndrome. Also, these recommendations are for
infants during sleep. While the infant is awake and observed,
some "tummy time" is necessary for developmental reasons. Side
sleeping is less risky than stomach sleeping, and there are
several devices to help keep you infant propped up, but as soon as
they start squirming a lot you probably cannot use them.
Constant worrying about the possibility of SIDS and constant checking
on the baby will not safeguard a child from SIDS. It will only serve
to exhaust the parents and to increase their worries. The first few
months (and beyond!) is a time best spent by enjoying, loving, and
watching your child grow and develop. Recognize the fact that you
are not alone in your concern for your child. And remember that SIDS
is not a common occurrence - of every 1000 babies born, 998 infants
will NOT become SIDS victims.