title: Defining early adolescent childbearing.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Maureen G
authors.initials: MG
authors.lastname: Phipps
authors.forename: MaryFran
authors.initials: M
authors.lastname: Sowers
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D000704:Analysis of Variance; D001719:Birth Certificates; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008423:Maternal Age; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D011256:Pregnancy Outcome; D011253:Pregnancy in Adolescence; D011295:Prenatal Care; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects