Sudden unexplained infant deaths among American Indians and whites in North and South Dakota.

Differences in risk factors for sudden unexplained infant death (SUID) were studied among American Indian and White infants in North and South Dakota. From 1977 to 1984, the incidence of SUID was 3.9 times higher among Indians compared with Whites. Indian SUID cases appeared to die at a slightly younger age than Whites, and the association of male gender and young maternal age with SUID was weak or absent among Indians. Low maternal education and late or no prenatal care were strongly related to SUID in both races. The Indian-White risk ratio was unaltered by adjustment for birthweight and maternal age but declined to 2.5 (95% confidence intervals = 1.9, 3.4) when adjusted for maternal education and trimester prenatal care began.