The sudden infant death syndrome--reassessment of growth retardation in relation to maternal smoking and the hypoxia hypothesis.

Data from an earlier study on postnatal growth and the sudden infant death syndrome (SIDS) by Peterson et al. (Am J Epidemiol 1974;99:389-94) were reanalyzed in light of new evidence on the effects of maternal smoking on prenatal and postnatal growth and on the relative risk of SIDS. The data set available for reanalysis consisted of weight and length (crown to heel) measurements at birth and autopsy for 155 babies diagnosed with SIDS in King County, Washington, in 1968-1971. The comparison group consisted of 270 contemporary living peers with weight and length data available. This reanalysis reveals that the retarded growth pattern of SIDS victims is remarkably similar to those of babies born to mothers who smoke during pregnancy. Known and suspected effects of maternal smoking on the fetus and neonate can account for increased susceptibility of death from a variety of causes, including SIDS. The association, if confirmed by further studies, could help clarify the pathogenesis of SIDS in victims with postmortem evidence of antemortem hypoxia with or without a history of periodic apnea.