A longitudinal study of contraception and pregnancy outcome in a representative sample of young Swedish women.

The prevalence of contraception and pregnancy history in the same women, aged 19 and 24 years, was assessed in a longitudinal cohort study by means of a postal questionnaire. A one-in-four random sample of all the women born 1962, resident in the city of Göteborg in 1981, was obtained from the population register (n = 656). The response rate was 91%. Respondents from 1981 were re-assessed in 1986 (response rate: 83%). The respondents from 1986 (n = 488) represent 74% of the original sample from 1981. Contraceptive usage in the same women aged 19 and 24 years (in brackets) was as follows: Oral contraception (OC) 47% (51%); intrauterine device 3% (11%), p less than 0.01; barrier methods 11% (11%); depot gestagen 0 (0.2%); no contraception 39% (26%), p less than 0.05. OCs were being taken or had been taken by 89%. Reasons given for cessation of OC were as follows: Contraception not required 10% (15%); fear of OC 26% (29%); menstrual disorder 17% (14%); weight increase 18% (10%), p less than 0.05; mental side effects 15% (9%); desire to become pregnant 7% (17%), p less than 0.01. Pregnancies (n = 362) were reported by 194 (43%) of the women. 44% of the pregnancies terminated in legal abortion. The medical complication rate following legal abortion was 15%. Thus, despite the availability of effective contraception, the ratio of legal abortions to live births was high. Fear of side effects was the commonest reason for discontinuing OC.