EFFECTS OF HEAVY MATERNAL SMOKING ON INTRAUTERINE GROWTH-PATTERNS IN SUDDEN INFANT DEATH VICTIMS AND SURVIVING INFANTS

Sudden infant death (SID) is associated with both intrauterine growth retardation and maternal smoking during pregnancy. Here, we investigat ed if the statistical association between maternal smoking and SID is direct or mediated through the well-known growth retarding effects of heavy maternal smoking on the fetoplacental unit. We analysed data fro m a population-based prospective cohort study (181 cases, total newbor n population 227,791 births) within the Westphalian Perinatal Inquiry in Germany between 1990 and 1994. SID victims whose mothers did not sm oke had a normal mean birth weight (mean 3415.5 vs 3431.5 g), length ( mean 51.46 vs 51.66 cm), and body mass index (BMI) (mean 12.8 vs 12.8 kg/m(2)) when compared to surviving children. In contrast, SID victims of mothers who smoked heavily (> ten cigarettes per day) had a signif icantly lower birth weight (2911.21 g vs 3148.34 g), length (48.98 vs 50.39 cm), and BMI (11.8 vs 12.4 kg/m(2)) when compared to surviving c hildren whose mothers smoked heavily. Stratification for gestational a ge revealed that these differences are mainly caused by preterm SID in fants. Conclusion The statistical association between maternal smoking and SID mainly results from effects of tobacco smoke on the fetoplace ntal unit which, in later SID victims, appears to be more susceptible to the growth retarding effects of cigarette smoking.