Adolescent sexual behavior during periods of increase and decrease in the abortion rate.

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=286665) 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 …