Vitamin A and sudden infant death syndrome in Scandinavia 1992-1995

Aim: To assess the effect of vitamin supplementation on the risk of sudden infant death syndrome (SIDS). Methods: The analyses are based on data from the Nordic Epidemiological SIDS Study, a case-control study in which parents of SIDS victims in the Scandinavian countries were invited to participate together with parents of four matched controls between 1 September 1992 and 31 August 1995. The odds ratios presented are computed by conditional logistic regression analysis. Results: The crude odds ratio in Scandinavia for not giving vitamin substitution was 2.8 (95% CI (1.9, 4.3)). This effect was statistically significant in Norway and Sweden, which use A and D vitamin supplementation, but not in Denmark, where only vitamin D supplementation is given. The odds ratios remained significant in Sweden when an adjustment was made for confounding factors (OR 28.4, 95% CI (4.7, 171.3)). Conclusion: We found an association between increased risk of sudden infant death syndrome and infants not being given vitamin supplementation during their first year of life. This was highly significant in Sweden, and the effect is possibly connected with vitamin A deficiency. This effect persisted when an adjustment was made for potential confounders, including socioeconomic factors.     

Sudden unexpected death in infants under 3 months of age and vaccination status- -a case-control study

AIMS: To determine whether DTPP+Hib vaccination (diphtheria, tetanus, pertussis, poliomyelitis +/- haemophilus) increased the risk of sudden unexpected death (SUD) in children under 3 months of age. METHODS: We conducted a multicentre case-control study in the 28 French 'SIDS Centers'. Case selection was based on death labelled sudden infant death syndrome (SIDS) of an infant aged between 30 and 90 days. Three living controls were selected, matched for sex, gestational age and born immediately after the victim in the same maternity unit. RESULTS: We identified 114 cases of SUD aged between 30 and 90 days and 341 live controls matched for age and sex and born in the same maternity unit as the case. DTPP+/-Hib immunization did not increase the risk of SUD (OR 1.08) (95% CI 0.49, 2.36) in children under 3 months of age when adjusted for sleeping position, illness in the week before death, maternal tobacco consumption, birth weight, type of mattress, breastfeeding and sex. However, low birth-weight (6.53 [2.29, 18.9]), multiple birth (5.1 [1.76, 15.13]), no breastfeeding (1.77 [1.1, 2.85]), prone sleeping position (9.8 [5, 8, 18, 9]), soft mattress (3.26 [1.69, 6.29]), recent illness (3.44 [1.84, 6.41]) and parental smoking (1.74 [1.2, 2.96]) were confirmed as risk factors in early SIDS. CONCLUSIONS: DTPP+/-Hib immunization is not a risk factor for early SUD. In this population, we found the same risk factors as described for SIDS.     

Consent for autopsy research for unexpected death in early life

Research in sudden death in fetuses (stillbirth) and infants (sudden infant death syndrome [SIDS]) is urgently needed, particularly in high-risk populations involving socioeconomic disadvantaged families. Essential to such research is the analysis of fetal and infant tissues at autopsy. Obtaining consent for donating autopsy tissues for research is especially problematic in socioeconomically disadvantaged populations in which mistrust of the medical establishment often exists. In this article, we present communication strategies for obtaining consent for research in autopsy tissues of stillbirth and SIDS cases in socioeconomically disadvantaged populations. Recommendations are provided about preparation for and the timing, setting, and content of the consent interview. The same lines of open and transparent communication delineated in this article are applicable to obtaining consent for the autopsy and autopsy research. Although the grief responses to the untimely death of the fetus or infant are universal and the recommendations of this essay are widely applicable to the general population, the expression of this grief and feelings toward autopsy-based research in socioeconomically disadvantaged populations may raise special issues that health care workers should be aware of when obtaining consent for research on autopsy-derived tissues.