Italian national data bank of stillbirth versus SIDS. A new epidemiological and pathological perspective

Aim: To contribute to the epidemiological evaluation of the risk factors underlying unexplained fetal death and SIDS, as imposed by the Italian Law 31/2006, and a more balanced assessment of the morphological substrates of these deaths. Methods: Fifty nine sudden fetal deaths and 61 SIDS cases were compared to 120 matched controls randomly selected from live born child of mother living in the same catchment area, to assess if one or more exogenous variables could promote unexpected death. In-depth anatomo-pathological examinations were performed on the autonomic nervous and cardiac conduction systems in the dead victims. Results: Prematurity and maternal smoking are determinant factors of infant mortality. In particular mothers smoking during pregnancy experienced a two-fold increase in risk of sudden fetal death and SIDS relative to mothers who never smoked. Besides, the localization and the nature of a variety of specific congenital abnormalities of the autonomic nervous system and of the cardiac conduction system were highlighted as morphological substrates of the pathophysiological mechanism of unexpected death. Conclusion: Maternal smoking during pregnancy is associated with a significantly increased risk of unexpected fetal mortality and SIDS. Thus it is important to promote information campaigns to reduce tobacco use particularly in young woman.