A common scenario is that of a previously well
infant being put into a crib for a nap and then found dead some time later
by the parents. Cause of death remains unexplained after investigation. From
epidemiological studies, risk of SIDS is found to be increased with a
variety of factors. Demographic factors include the age of the infant (2 to 4 months),
male predominance, high birth order, lower socioeconomic status, and younger maternal age.
Antenatal factors include low birth weight, low gestational age, multiple pregnancies,
maternal smoking, and substance-abusing mother. Postnatal factors include parental
smoking, prone sleeping position, overheating of bedroom, soft mattress with excessive
wrappings, and recent respiratory tract infections. Beast-feeding appears to
have a protective effect from SIDS. By far, the most significant factor in
the last few years has been the avoidance of a prone sleeping position,
which has led to the reduction in the incidence of SIDS in many countries.