1. Tell all your child's caregivers to put him to sleep on his back. It's not totally clear why this position is so effective against SIDS, but it is. One theory is that some infants' breathing instincts aren't fine-tuned at birth. If they sleep tummy down and end up rebreathing a pocket of air until their oxygen supply runs low, no internal alarm prods them to try to turn their head. Back-sleeping eliminates this risk -- in fact, babies whose parents and caregivers position them that way are two to three times less likely to succumb to SIDS.
But once you institute the "back to sleep" rule, your child must always go to sleep that way, even for naps. A recent study by the NICHD found that babies who normally sleep on their back and then are placed on their side or stomach, even just once, are seven to eight times more likely to die of SIDS on that occasion than those who consistently back-sleep. The reasons are unclear, researchers say, but babies who are accustomed to sleeping on their back apparently have difficulty adjusting to the dramatic change.
The lesson: Everyone who watches your child must put him on his back for sleep, including day-care workers (recent research indicates that 20 percent of child-care centers that provide overnight care place babies to sleep on their stomach at least occasionally). Don't forget the neighbor who babysits in emergencies -- up to 50 percent of SIDS cases occur when a child is with a caregiver other than a parent, according to the SIDS Alliance of Illinois. "Refrain from tummy sleep until your baby is old enough to have rolled over a few times on his own, usually at about 5 to 6 months," says Bradley Thach, M.D., of the Washington University School of Medicine, in St. Louis.
2. Don't let your baby snooze in your bed. It's tempting to bring your newborn into your bed, at least occasionally. And more moms and dads are making it a permanent arrangement: Nearly 13 percent of babies under 8 months of age usually share an adult bed at night, up from just 5.5 percent in 1993, according to the NICHD.
Don't jump on the bandwagon. "Adult beds are not designed for babies," says Marian Willinger, Ph.D., special assistant for SIDS at the NICHD, in Bethesda, Maryland. "An infant can get pinned between the mattress and the bed frame, or sink into the pillow and quilt." The crowded environment might also cause the child to rebreathe air pockets, just as tummy-sleeping can. Possibly for these reasons, a baby who sleeps with Mom or Dad in a grown-up bed is nearly one-and-a-half times more likely to die of SIDS, according to one preliminary study. Most experts consider that increase to be negligible, says Fern R. Hauck, M.D., a SIDS researcher at the University of Virginia, in Charlottesville, but the risks can quickly rise if parents cover their baby with a comforter, or if either or both have been drinking, are taking sleep-inducing drugs, or are very tired -- which may make them unaware that they're crowding their child. If Mom or Dad smokes, the risks increase too (for more on why, see Tip #6).
Putting your little one in bed with her big sister or brother is even more dangerous: A recent study found that sleeping with one or more siblings makes a baby nearly five-and-a-half times more likely to die of SIDS. "This might be because siblings don't or can't monitor the infant or make as much of an effort to give him space," Dr. Hauck speculates.