title: Sexual activity among adolescents in romantic relationships with friends, acquaintances, or strangers.
abstract: OBJECTIVE
  To explore the influence of preexisting social ties between romantic partners (ie, knowing the partner as a friend or acquaintance before a relationship was considered "romantic" by the adolescent) on sexual risk behaviors among adolescents.
  
  
  METHODS
  By using data from 6658 adolescents from Wave II of the National Longitudinal Study of Adolescent Health, we examined associations between preromantic social ties between partners and several sexual risk behaviors using logistic regression analyses.
  
  
  METHODS
  Whether the couple had intercourse, and if they did have intercourse, whether the couple talked about contraception or sexually transmitted infections and whether one of them used some method of birth control every time they had sexual intercourse.
  
  
  RESULTS
  Knowing one's partner as a friend (vs being acquaintances) before a romantic relationship was protective against engaging in sexual intercourse for male and female adolescents (odds ratios and 95% confidence intervals, 0.66 [0.51-0.86] and 0.76 [0.62-0.94], respectively). For female adolescents, sexually active relationships with partners they had not known before the romantic relationship began were less likely to include discussions of sexually transmitted infections or contraception, and were less likely to include consistent use of birth control (odds ratios and 95% confidence intervals, 0.37 [0.22-0.62] and 0.62 [0.39-0.99], respectively). Preromantic social ties did not play a statistically significant role for these outcomes among male adolescents (odds ratios and 95% confidence intervals of friends and of those who had not met, respectively, are 0.85 [0.60-1.18] and 0.90 [0.50-1.63] for talking about sexually transmitted infections or contraception and 0.93 [0.66-1.30] and 1.17 [0.71-1.96] for always using birth control).
  
  
  CONCLUSIONS
  The existence and nature of an adolescent's prior relationship with a future romantic partner have significant implications for an adolescent couple's later sexual decisions, but patterns differ for male and female adolescents.
authors.affiliation: Department of Maternal and Child Health, The University of North Carolina at Chapel Hill, NC 27599, USA.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Kaestle
authors.forename: Carolyn Tucker
authors.initials: CT
authors.lastname: Halpern
mesh_terms: D000293:Adolescent; D003142:Communication; D003267:Contraception / Q000523:psychology* / Q000706:statistics & numerical data; D005260:Female; D033062:Friends / Q000523:psychology*; D006801:Humans; D007398:Interpersonal Relations; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D018570:Risk Assessment; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior / Q000523:psychology* / Q000706:statistics & numerical data; D012747:Sexual Partners / Q000145:classification / Q000523:psychology*; D012749:Sexually Transmitted Diseases / Q000517:prevention & control* / Q000523:psychology; D011795:Surveys and Questionnaires; D014481:United States