The rate of decline in PNM was greater and more rapid for white infants than black infants. However, among white infants, PNM declined slower than NM, and the proportion of postneonatal deaths among whites was greater than among blacks. Compared with white infants, the rate of decline caused by birth defects, infections, injuries, and perinatal conditions was slower for black infants. However, the twofold difference in SIDS mortality between blacks and whites increased further. Thus, racial differences and trends in autopsy rates account for neither the higher SIDS mortality among black infants nor the important mortality decline during the 1990s for both races.
Birth defects remain the leading cause of infant mortality in the United States.
Improved infant survival, the increased use of folic acid, and increased prenatal diagnosis may have reduced the proportion of postneonatal deaths caused by birth defects. Moreover, PNM caused by motor vehicle crashes decreased for white infants but increased for black infants during the period. Although the rate of PNM caused by fire for black infants remained at approximately 2.5 times that of white infants in 1994, the relative risk of fire-related PNM decreased by nearly two thirds during the study period. Postneonatal homicide increased steadily as a cause of postneonatal death during 1980-1994 among white infants and black infants. In 1992, the rate of homicide among black infants was approximately 2.5 times that of white infants.