title: [Profile of sexual behavior in 12- to 19-year-old Mexican adolescents. Results of ENSA 2000].
abstract: OBJECTIVE
  To describe traits associated with sexual behaviors in Mexican adolescents, their knowledge about contraception, and factors associated with pregnancy and utilization of contraceptives during first sexual intercourse.
  
  
  METHODS
  Data from the Mexican National Health Survey 2000 (ENSA 2000) were analyzed. This study, conducted between September 1999 and March 2000, was a complex survey with a probabilistic, stratified, and cluster sampling design. The sample population included 15 241 adolescents 12 to 19 years of age. Data analysis included descriptive statistics and a chi-squared test for differences of proportions; also, logistic regression was used to obtain odds ratios.
  
  
  RESULTS
  A total of 69.2% adolescents reported knowledge of at least one contraception method; 16.4% of subjects reported having had sexual intercourse. Males initiated sexual intercourse earlier than females and only 37% of all adolescents utilized contraceptives during their first sexual intercourse. Logistic regression analysis showed that being male, having a higher education, having knowledge of at least one contraception method, and having initiated sexual intercourse at an older age, were factors associated with utilization of a contraception method in their first sexual intercourse. A total of 55.7% of sexually active female adolescents had been pregnant. Pregnancy among adolescents was associated with low educational level, sexual activity at early age, and to have sometime lived in free union.
  
  
  CONCLUSIONS
  The majority of sexually active adolescents did not use contraception during their first sexual intercourse, rendering them at risk of unwanted pregnancies.
authors.affiliation: University of California, San Diego, Estados Unidos de América, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: González-Garza
authors.forename: Rosalba
authors.initials: R
authors.lastname: Rojas-Martínez
authors.forename: María I
authors.initials: MI
authors.lastname: Hernández-Serrato
authors.forename: Gustavo
authors.initials: G
authors.lastname: Olaiz-Fernández
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000328:Adult; D002648:Child; D003267:Contraception / Q000379:methods / Q000523:psychology / Q000706:statistics & numerical data; D004522:Educational Status; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006306:Health Surveys; D006801:Humans; D008297:Male; D008800:Mexico; D011247:Pregnancy; D011253:Pregnancy in Adolescence / Q000706:statistics & numerical data; D012424:Rural Population; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014505:Urban Population