tokens: We investigated this association , according to the type of progestagen included in third - generation ( i . e . , desogestrel or gestodene ) and second - generation ( i . e . , levonorgestrel ) oral contraceptives , the dose of estrogen , and the presence or absence of prothrombotic mutations METHODS : In a nationwide , population - based , case - control study , we identified and enrolled 248 women 18 through 49 years of age who had had a first myocardial infarction between 1990 and 1995 and 925 control women who had not had a myocardial infarction and who were matched for age , calendar year of the index event , and area of residence .