AdventureDad

• Get medical care early in pregnancy, preferably within the first three months, followed by regular checkups at the doctor's office or health clinic. Make every effort to assure good nutrition. These measures can reduce the risk of premature birth, a major risk factor for SIDS.

• Do not smoke, use cocaine, or use heroin. Tobacco, cocaine, or heroin use during pregnancy increases the infant's risk for SIDS.

• Take care to prevent becoming pregnant during the teenage years. If you are a teen and already have one infant, take extreme caution not to become pregnant again. The SIDS rate decreases for babies born to older mothers. It is highest for babies born to teenage mothers. The more babies a teen mother has, the greater at risk they are.
  

• Wait at least one year between the birth of a child and the next pregnancy. The shorter the interval between pregnancies, the higher the SIDS rate.
  

• Place infants to sleep on their backs, even though infants may sleep more soundly on their stomachs. Infants who sleep on their stomachs and sides have a higher rate of SIDS than infants who sleep on their backs.

• Place infants to sleep in a baby bed with a firm mattress. There should be nothing in the bed but the baby - no covering, no pillows, no bumper pads and no toys. Soft mattresses and heavy covering are associated with the risk for SIDS. 

• Do not over-clothe the infant while he/she sleeps. Keep the room at a temperature that is comfortable for you. Overheating an infant may increase the risk for SIDS.

• Avoid exposing the infant to tobacco smoke. Don't have your infant in the same house or car with someone who is smoking. The greater the exposure to tobacco smoke, the greater the risk of SIDS. 

• Breast-feed babies whenever possible. Breast milk decreases the occurrence of respiratory and gastrointestinal infections. Studies show that breast-fed babies have a lower SIDS rate than formula-fed babies do.

• Avoid exposing the infant to people with respiratory infections. Avoid crowds. Carefully clean anything that comes in contact with the baby. Have people wash their hands before holding or playing with your baby. SIDS often occurs in association with relatively minor respiratory (mild cold) and gastrointestinal infections (vomiting and diarrhea).

• Consider using home monitoring systems (apnea/bradycardia monitors) in an attempt to prevent sudden death in high-risk infants.The risk of SIDS in the following groups exceeds that of the general population by as much as 5 to 10 times:

            - Infants born weighing less than 3.5 pounds.
            - Infants whose sibling died of SIDS.
            - Infants exposed to cocaine, heroin, or                     methadone during the pregnancy.
            - The second or succeeding child born to a                 teenage mother.
            - Infants who have had an apparent                             life-threatening event.

I would also like to mention co-sleeping and make sure parents are careful when sharing beds with a small baby.  Don't bring her into your bed if you're a heavy sleeper, move around a lot, after drinking alcohol, and make sure the baby can't get stuck between the mattresses or fall out of bed.  Stupid advice, I know.  But babies die every year because of these stupid reasons.

Information taken from American SIDS institute and National Institute of Health