Mortality from intentional and unintentional injury among infants of young mothers in Colorado, 1986 to 1992.

OBJECTIVES: To investigate the association between maternal age and other risk factors and infant injury deaths in the state of Colorado from 1986 to 1992.
DESIGN: A retrospective cohort design was used to compare rates of unintentional and intentional infant injury mortality by maternal age group. A case-control design explored the importance of various risk factors, particularly maternal age, using multivariate logistic regression. PARTICIPANTS: The 2 case groups comprised all unintentional and intentional injury deaths in the first year of life. The control group was a random sample of both survivors and noninjury deaths selected from the entire birth cohort.
RESULTS: The infant injury mortality rate for the 322766 live births in Colorado from 1986 to 1992 was 3.1 per 10000. Intentional injury death rates were highest for infants of teenaged mothers, peaking at 10.5 per 10000 live births for mothers aged 16 years. Unintentional injury death rates were highest for infants of mothers aged 20 to 24 years, peaking at 3.7 per 10000 live births for 22-year-old mothers. For intentional injury death, maternal marital status had a significant impact on maternal age; compared with the baseline group of married mothers older than 24 years, significantly higher risks were observed for infants of teenagers who were married (odds ratio [OR] = 32.0; 95% confidence interval[CI], 9.9-104.0) but also in infants of older mothers who were unmarried (OR = 3.6; 95% CI, 1.0-13.0 for unmarried mothers aged 20-24 years and (OR = 7.7; 95% CI, 2.4-25.0 for those > 24 years). Black race (OR = 3.5; 95% CI, 1.4-9.4) was also associated with intentional injury death. For unintentional injury death, the highest risk was for infants of mothers aged 20 to 24 years and unmarried (OR = 3.9; 95% CI, 1.7-9.3). Risk was also elevated for infants of married teenaged mothers (OR = 3.5; 95% CI, 0.7-17.8) but was not significantly different from the baseline group for unmarried teenagers, married 20- to 24-year-old mothers, or unmarried mothers aged 25 years or older. Risk was increased by the presence of older siblings (OR = 1.5 per sibling; 95% CI, 1.2-2.0).
CONCLUSIONS: Maternal age and marital status significantly affect the rate of both unintentional and intentional infant injury mortality. These results suggest that child abuse prevention strategies should be targeted to teenaged mothers, and that strategies designed to prevent unintentional injuries should focus particularly on parents or caretakers of infants born to unmarried mothers in their early 20s as well as married teenagers.