title: Sexual intercourse and the age difference between adolescent females and their romantic partners.
abstract: BACKGROUND
  The age difference between a female and her partner may influence relationship dynamics in ways that put the female at increased risk of unintended pregnancies and sexually transmitted diseases. Very little is known, however, about how romantic involvement progresses to intercourse, particularly among adolescent females with older male partners.
  
  
  METHODS
  Data from 1,975 female participants in the National Longitudinal Study of Adolescent Health were analyzed using logistic regression to determine whether the age difference between an adolescent female and her romantic partner is a risk factor for sexual intercourse.
  
  
  RESULTS
  Adolescent females involved with an older partner have higher odds of having intercourse with that partner than females with partners their own age, after adjustment for demographic covariates. The magnitude of this association is most dramatic among the youngest females--for example, the odds of intercourse among 13-year-old females with a partner six years older are more than six times the odds among 13-year-old females with a same-age partner (odds ratio, 6.4), while 17-year-old females with partners six years older have about twice the odds of intercourse when compared with those who have a same-age partner (2.1).
  
  
  CONCLUSIONS
  Young adolescent females with substantially older partners are much more likely than their peers to have sex with their partner, which exposes them to the risks of pregnancy and sexually transmitted diseases.
authors.affiliation: Department of Maternal and Child Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Kaestle
authors.forename: Donald E
authors.initials: DE
authors.lastname: Morisky
authors.forename: Dorothy J
authors.initials: DJ
authors.lastname: Wiley
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D002648:Child; D003075:Coitus; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D012044:Regression Analysis; D012747:Sexual Partners / Q000145:classification*; D014481:United States / Q000453:epidemiology