title: Maternal age and the size of White, Black, Hispanic, and mixed infants.
abstract: OBJECTIVE
  To clarify the interaction between maternal age and race in the prediction of infant size at birth.
  
  
  METHODS
  Birth certificate data was used to study the relationship between maternal age, race/ethnicity, and the size of term, singleton infants born to 91,061 healthy, non-smoking, non-substance using, primigravidas.
  
  
  RESULTS
  Maternal race/ethnicity (Black race: OR: 1.95, 95% CI: 1.49-2.56; Hispanic ethnicity: OR: 1.38, 95% CI: 1.19-1.61) and the interaction term, maternal age x race/ethnicity (OR: 1.06, 95% CI: 1.01-1.11) predicted small-for-gestational age (SGA) birth. The strength of the association between Black race and SGA delivery increased and the strength of the association between Hispanic ethnicity and SGA delivery decreased with age (P < 0.001 for trend). Thus, Black and Hispanic teenagers were more likely to have SGA babies than White teenagers (1.7% and 1.6%, respectively compared to 1.2%; P = 0.003). However, Black women who postponed childbearing until their mid-twenties were more likely to have SGA babies than their Hispanic and White counterparts (2.6% compared to 1.2%, and 1.0%, respectively; P < 0.0001).
  
  
  CONCLUSIONS
  The findings suggest that acquired maternal characteristic(s) cause the reproductive health of Black primigravidas to deteriorate and Hispanic primigravidas to improve with age.
authors.affiliation: Department of Pediatrics, University of Colorado Health Sciences Center, Denver, Colorado 80218, USA. jeanelle.sheeder@uchsc.edu
authors.forename: Jeanelle
authors.initials: J
authors.lastname: Sheeder
authors.forename: Dennis
authors.initials: D
authors.lastname: Lezottte
authors.forename: Catherine
authors.initials: C
authors.lastname: Stevens-Simon
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000367:Age Factors; D001724:Birth Weight; D005220:Fathers; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008423:Maternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000208:ethnology*; D044465:White People