Risk factors for infant mortality in Down's syndrome: a nationwide study

The aim of this study was to assess risk factors for the excessive infant mortality rates (IMR) of infants with Down's syndrome (DS). The study population included all 847 Jewish DS births in Israel during 1979-83 and 1987-91. Cases were identified through the National DS Registry. Data were abstracted from hospitalisation records. Ninety-one per cent of the DS diagnoses were confirmed by a cytogenetic analysis. The DS IMR were 24.3 times higher than in the general population. Major risk factors affecting DS IMRs were health status, time period of birth and residential arrangement of the infant. Other known risk factors for infant mortality, such as young maternal age, high birth order and low birthweight, had a weaker impact on IMR in the DS population. Our results imply that the current better survival of infants with DS is a function of the changing attitude towards this population. The study identifies a potential for further reduction in the mortality rates of DS infants, provided there is willingness to adopt a more active and supportive treatment and further changes in ethical codes of the public.