Objectives: This study determined the age group for the case definition of early adolescent childbearing based on rates of adverse clinical outcomes.
Methods: We examined rates of infant mortality, very low birthweight (<1500 g), and very preterm delivery (<32 weeks) per 1000 live births for all US singleton first births (n = 768 029) to women aged 12 to 23 years in the 1995 US birth cohort.
Results: Rates of infant mortality, very low birthweight, and very preterm delivery were graphed by maternal age. In all 3 cases, the inflection point below which the rate of poor birth outcome is lower and begins to stabilize is at 16 years; therefore, mothers 15 years and younger were grouped together to determine the case definition of early adolescent childbearing. The inflection points were similar when outcomes were stratified by the 3 largest US racial/ethnic groups (non-Hispanic White, non-Hispanic Black, and Mexican American).
Conclusions: From this population-based analysis of birth outcomes, we conclude that early adolescent childbearing is best defined as giving birth at 15 years or younger.