The leading cause of death in otherwise healhty babies more than a month old is SIDS, or sudden infant death sundrome. It occurs in about 50 of every 100,000 births in the U.S. SIDS applies to any infant whose death is sudden and unexplained.

Usually, the infant is found dead after having been put to sleep, and a subsequent autopsy finds absolutely nothing wrong with the baby. For parents, it is the most horrific of experiences.

No one knows what causes SIDS but there are several risk factors asociated with it. Babies who are born prematurely are at increased risk for SIDS; so are those who are exposed to tobacco smoke. Laying an infant to sleep on his or her stomach also increases the risk, as does excess bedding, a soft sleep surface or the presence of stuffed animals.

There is no surefire way to prevent SIDS, but in light of these known risks, parents can take precaustions to reduce its likelihood. Here are seven quick tips for avoiding SIDS.

--Don't smoke in the house

--Don't sleep with your baby in your bed. More and more evidence suggests that parents, especially overweight ones, may inadvertently smother their babies when they're sleeping with their child.

--Do choose a crib with a firm surface

--Do keep blankets and stuffed animals to a minimum. Infants have little control over their heads and may smother themselves in their bedding.

--Dp place baby on his or her back to sleep, never on the stomach.

--Do breastfeed if you can. One recent study showed that breastfed infants are five times less likely to have SIDS as forumula fed infants.

--Do use a pacifier. A recent study has noted that the use of pacifiers is associated with a 90 percent decrease in the risk of SIDS.

Click here to check out Dr. Manny's book The Check List (Harper Collins, 2007).

Dr. Manny Alvarez is the managing editor of health news at FOXNews.com, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.