title: Adolescent sexual behavior during periods of increase and decrease in the abortion rate.
abstract: OBJECTIVE
  To study changes in adolescent sexual behavior in periods of increase (1994-2000) and decrease (2001-2007) in the abortion rate.
  
  
  METHODS
  School surveys with self-administered questionnaires were carried out annually among eighth graders (mean age 14.8 years) and ninth graders (mean age 15.8 years) (N=286,665) in 1996/1997 and 2006/2007. Schools participated biennially. The proportions of respondents reporting noncoital (kissing, light petting, heavy petting) and coital (ever had sexual intercourse, intercourse at least 10 times, at least three partners) sexual experience and nonuse of contraception were studied.
  
  
  RESULTS
  Among adolescents, both coital and noncoital sexual experiences and the proportion of those not using contraception increased between 1996-1997 and 2000-2001 (P for trend <.01, all) and decreased from 2000-2001 onward (P<.001, all), except the proportion of at least 10 coital events, which did not decrease. Among sexually experienced adolescents, a similar increase in coital experiences (intercourse at least 10 times from 38.2% to 41.5%, at least three partners from 27.8% to 30.7%, P<.001) and in not using contraception (from 17.2% to 19.1%, P=.002) was seen before 2000-2001, but after that the only significant change was a further increase in the proportion of those reporting intercourse at least 10 times (from 41.5% to 47.8%, P<.001).
  
  
  CONCLUSIONS
  The proportion of adolescents reporting noncoital sexual experiences, intercourse, or not using contraception increased in the 1990s and decreased in the 2000s, reflecting the changes in the abortion rate. However, as the abortion rate decreased, the intensity of sexual activity further increased among sexually experienced adolescents, suggesting that the fall in the abortion rate may be due to contraception and more effective sexual education.
  
  
  METHODS
  : III.
authors: From the Tampere School of Public Health and the Medical School, University of Tampere, Tampere, Finland; the Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland; and the Department of Health Care, Helsinki Metropolia University of Applied Sciences, Helsinki, Finland.
authors: Kobra
authors: K
authors: Falah-Hassani
authors: Elise
authors: E
authors: Kosunen
authors: Rahman
authors: R
authors: Shiri
authors: Jukka
authors: J
authors: Jokela
authors: Arja
authors: A
authors: Liinamo
authors: Arja
authors: A
authors: Rimpelä
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data*; D000293:Adolescent; D000294:Adolescent Behavior; D003075:Coitus; D003268:Contraception Behavior; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D011247:Pregnancy; D012725:Sexual Behavior; D011795:Surveys and Questionnaires