Risk factors for infant homicide in the United States

Homicide is the leading cause of infant deaths due to injury. More than 80 percent of infant homicides are considered to be fatal child abuse. This study assessed the timing of deaths and risk factors for infant homicide.

Using linked birth and death certificates for all births in the U.S. between 1983 and 1991, we identified 2776 homicides occurring during the first year of life. Birth-certificate variables were reviewed in both bivariate and multivariate stratified analyses. Variables potentially predictive of homicide were selected on the basis of increased relative risks among subcategories with adequate numbers for stable estimates.

Half the homicides occurred by the fourth month of life. The most important risk factors were a second or subsequent infant born to a mother less than 17 years old (relative risk, 10.9) or 17 to 19 years old (relative risk, 9.3), as compared with a first infant born to a mother 25 years old or older; a maternal age of less than 15 years, as compared with an age of at least 25 years (relative risk, 6.8); no prenatal care as compared with early prenatal care (relative risk, 10.4); and less than 12 years of education among mothers who were at least 17 years old (relative risk, 8.0), as compared with 16 or more years of education.

Childbearing at an early age was strongly associated with infant homicide, particularly if the mother had given birth previously. Our findings may have implications for prevention.