['There is no doubt, oral contraceptives are a safe, reversible and commonly used method of contraception. Ever use is about 80 % in developed countries and current use of OCs about 40 %. Almost all information about prevalence of OC use came from cross-sectional studies and did not distinguish between high- and low-dose OCs. This paper deals with the prevalence of OC use as it was observed during lifetime of a large cohort of German women by calendar year and estrogen content.', "The prevalence of OC use between 1980 to 1999 was analysed on occasion of an interim analysis of the German cohort study on women's health. This analysis is based on more than 10 000 women with about 390 000 women-years of observation.", 'The proportion of women under the age of 50, that ever used OCs, increased steeply from 1980, i. e. from 62 % (1980) to about 90 % from 1996 onward. The proportion of current users in a given calendar year rose from 44 % (1980) to 49 % (1991-95) and dropped after the "pill crisis 1995". The percentage of current users who used high-estrogen-dose OCs dropped from 32 % (1980) to 5 % (1999). In contrast, the percentage of users of low-dose OCs of the 2nd generation steeply increased as was the percentage of users of the 3rd generation pills, however the latter dropped after 1995.'] Do [ Trends of OC use 1980-1999 in a German cohort of women ]?