Sexual behaviour and early coitarche in a national sample of 17 year old Swedish girls

Objective: To evaluate sexual behaviour in 17 year old girls, using data fr om a national survey on adolescent sexuality. Method: The study was based on two samples of 17 year olds, comprising 2% o f the population born in 1973 and carried out in 1990. A school sample and a sample of school non-attenders were recruited in a two step procedure. Da ta were collected by anonymous self administered questionnaires. 2583 quest ionnaires were distributed. Response rates from students was 92%, fur schoo l non-attenders 44%. 1121 female students and 118 female school dropouts re sponded. Results: 64% of the student girls had experienced their first intercourse; 16% were "early starters" with coitarche before age 15. STD and pregnancy w ere reported by 15% of early starters and pregnancy by 14%, p<0.001 and 0.0 02 respectively when compared with later starters. The number of coital par tners, experience of first date intercourse, and of oral and anal sex was h igher in the early starters, p<0.001. Early starters reported menarche at a ge 11 or earlier more often than the later starters (OR 2.30, 95% CI 1.48-3 .56), as well as a perceived social age exceeding the chronological by 2 ye ars (OR 1.94, 95% CI 1.34-2.80). Sexual abuse was reported by 20% of the ea rly and 11% of the later starters, p=0.002. Among school non-attenders no s ignificant differences were found with regard to age for coitarche. A major ity of 83% of the girls had experienced voluntary intercourse, and 49% were early starters. Five girls were mothers. STD was reported by 19% and induc ed abortion by 14%. Sexual abuse was alleged by 28%. Conclusion: Coitarche before age 15 is related to early menarche and high p erceived social age. High number of partners and first date intercourse mak e early starters at increased risk for STD and unintended pregnancy. Sexual abuse is alleged more often by early starters.