Headache, menstruation and combined oral contraceptives: a diary study in 184 women with migraine.

Half of female migraineurs in childbearing age use combined oral contraceptives (COCs), but the influence of COCs on perimenstrual migraine is still unclear. We therefore aimed to analyze the risk of occurrence and persistence (i.e. presence for more than 1 day) of headache and migraine before and during menstruation in women with migraine, comparing users of COCs to non-users. We included 184 women with at least 1 day of menstruation recorded in a 90-day diary. We differentiated between (a) the 2 days before menstruation, (b) the first 3 days of menstruation and (c) the remaining days of menstruation and analyzed subgroups of women with (n=82) and without (n=102) COCs. In both groups, risk of any headache as well as that of migraine was highest during the first 3 days of menstruation with a hazard ratio of 1.9 and 2.1 for non-users and 2.1 and 2.2 for users. Although use of COCs showed no statistically significant overall effect, users were at higher risk for any headache premenstrually and non-users at higher risk for migraine on days 4+ of menstruation. In conclusion, use of COCs exerts only subtle differences on the course of perimenstrual migraine in menstruating women with migraine.