title: The relation of age to low birth weight rates among foreign-born black mothers: a population-based exploratory study.
abstract: BACKGROUND
  In stark contrast to the J or U- shaped relationship between age and low birth weight rates (< 2500g) seen among non-Latino White and Mexican American mothers, low birth weight rates among US-born Blacks are lowest in their teens and rise with increasing age (ie, weathering). The age-related pattern of low birth weight rates among foreign-born Black mothers is unknown.
  
  
  OBJECTIVE
  To determine the relationship between age and low birth weight rates among foreign-born Black mothers.
  
  
  METHODS
  Stratified analyses were performed on the 2003-2004 National Center for Health Statistics vital record datasets of foreign-born Black mothers. Maternal age was categorized into six subgroups. Potential confounding variables examined included marital status, parity, and prenatal care usage.
  
  
  RESULTS
  Foreign-born Black mothers (N = 143,235) demonstrated a J/U-shaped age-related pattern of low birth weight rates with the lowest rates observed among those in their twenties and early thirties. The subgroups of 15-19 and 35-39 year old mothers had low birth weight rates of 12.0% and 11.4% compared to 9.1% for 25-29 year old mothers; RR = 1.31 (1.22-1.42) and 1.25 (1.20-1.31), respectively. The J/U-shaped age-related pattern persisted independent of marital status, parity and prenatal care usage.
  
  
  CONCLUSIONS
  Foreign-born black mothers do not exhibit a weathering pattern of rising low birth weight rates with advancing age regardless of traditional individual-level risk factors. Further research into the age-related pattern of birth outcome among impoverished foreign-born Black mothers is warranted.
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Deal
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Bennett
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Rankin
authors.forename: James W
authors.initials: JW
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People / Q000706:statistics & numerical data*; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D017533:Marital Status / Q000208:ethnology; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000208:ethnology*; D011295:Prenatal Care; D012307:Risk Factors; D012959:Socioeconomic Factors; D014481:United States; D055815:Young Adult; D001741:Black or African American