Adverse effects on intrauterine growth and development and the risk of sudden infant death syndrome.

摘要

This study examined the relation between SIDS and factors that adversely affect fetal development. The hypothesis studied suggests that adverse effects during a critical period in utero may contribute to the etiology of sudden infant death syndrome (SIDS), possibly by impairing the normal development of the fetal central nervous system. Maternal cigarette smoking and anemia during pregnancy were studied extensively because both could lead to chronic fetal hypoxia. Data were analyzed from the National Institute of Child Health and Human Development (NICHD) Cooperative SIDS Study, a multicenter, population-based case-control study with a sample of 757 singleton SIDS infants and 1,514 controls, and from a case-control study of 193 SIDS cases and 1,930 controls, nested in the U.S. Collaborative Perinatal Project (CPP) cohort.;This dissertation provides some evidence that maternal cigarette smoking during pregnancy, and in particular during the early months of pregnancy, may be a more important risk factor for SIDS than passive inhalation of smoke during postnatal life. After adjustment for maternal age, infants born to mothers who smoked ten or more cigarettes per day and who were anemic (hematocrit less than 30 percent) during pregnancy were at a much higher risk of SIDS than infants born to mothers who did not smoke and were not anemic (odds ratio in the CPP Study = 4.0; 95 percent confidence limits, 2.1 and 7.4; odds ratio in the NICHD Study = 8.5; 95 percent confidence limits, 2.3 and 31.5).;Intrauterine growth retardation was clearly associated with SIDS in each of the gestational age categories and the growth retardation appeared to be symmetrical, consistent with the hypothesis that adverse factors may be acting at an early stage during pregnancy. Absence of early and consistent prenatal care was also strongly related to SIDS, which could not be explained by any combination of other measured predictors.;From a public health viewpoint, a portion of the excess risk of SIDS attributable to maternal smoking could be prevented. Under varying assumptions, the expected impact of a smoking-cessation program for pregnant women on the incidence of SIDS was estimated between 0.7 and 6.1 percent.