[Prevalence of Chlamydia trachomatis in women applying for abortion in Oslo 1985-91].

The prevalence of Chlamydia trachomatis was investigated in a retrospective study of 17,215 women who requested termination of pregnancy at Ullevål and Aker hospitals in Oslo during the years 1985-89 and 1991. The overall prevalence of C trachomatis decreased from 11.3% (267/2,354) in 1985 to 3.8% (112/2,958) in 1991. The reduction was considerable from 1985 to 1989 but only slight at the end of the period. The prevalence was higher in younger women during the whole period. In women < 25 years old the prevalence decreased from 16.7% in 1985 to 6.3% in 1991, and in women > or = 25 years old from 5.9% in 1985 to 1.8% in 1991.