Oral contraceptives and platelet aggregation

There are conflicting data in the literature concerning the effects of oral contraceptives on platelet aggregation. We studied 26 healthy women who used oral contraceptives for at least three months. The control group consisted of 25 healthy women of childbearing age, who were receiving no medications. No differences in platelet aggregation in response to adenosine diphosphate, epinephrine, and collagen were found between the two groups.