Abstract â–¡ 143

The reduction in SIDS by approximately 50% that has occurred following the recommendation that infants are not placed prone to sleep is now firmly established. However, SIDS continues to be the major cause of death in infancy. This paper discusses other established risk factors in SIDS, which may be casually associated with SIDS, and makes recommendations for future prevention efforts.

Side sleeping position A meta-analysis of 6 studies shows that this is a risk factor, probably due to the infant moving to the prone position (secondary prone). Although the pooled OR is not particularly high, many infants are placed on their side, so the removal of the risk factor might have a major impact on the incidence of SIDS. Reassuringly, infants who usually move from their back to prone do not appear to be at increased risk. A group at particular risk are infants who usually sleep on their side or back and are placed prone to sleep (unaccustomed to prone sleeping).

Smoking There is substantial evidence to conclude that maternal smoking causes a marked increase in SIDS (47 studies). Since the reduction the prevalence of prone sleeping position there have been 8 studies examining maternal smoking and SIDS (unadjusted OR = 4.7). Epidemiologically it is difficult to distinguish the effect of active smoking during pregnancy from involuntary postnatal tobacco smoking of the infant to smoking by the mother. The predominant effect from maternal smoking is from in utero exposure of the fetus. Clear evidence for environmental tobacco smoke exposure can be obtained by examining the risk of SIDS from paternal smoking where the mother is a non-smoker. The pooled unadjusted OR = 1.4 (6 studies)

Other established risk factors include bedsharing, especially where the mother is a smoker and socio-economic disadvantaged. Other risk factors where there is less agreement include not breastfeeding and pacifier use. Thermal factors are no longer important now that few infants sleep prone.

SIDS prevention programmes should promote back sleeping positions and not smoking during pregnancy. Efforts at avoiding second-hand smoke (environmental tobacco smoke) exposure, although of value in itself, distracts attention away from the major problem, namely in utero smoke exposure. Discouraging bed sharing needs to be handled with sensitivity, as many sections of society value this practice. In addition to SIDS, there are many health benefits for breastfeeding, so this should be encouraged. Finally we should advocate for policies that improve the socio-economic well-being of the disadvantaged sections of the community.