Epidemiological and clinical aspects of migraine in users of combined oral contraceptives.

Background: Migraine was assessed in users of combined oral contraceptives (COCs).

Study Design: This study had a cross-sectional design. Women with headaches were evaluated according to International Headache Society criteria and subsequently allocated to a "migraine" or "non-migraine" group.

Results: Migraine was detected in 80/480 women (16.6%), while other types of headache not classified as migraine were observed in 400 women (83.4%). Following COC use, headaches worsened in 32.5% and 19.3% [odds ratio (OR)=3.02; 95% confidence interval (CI)=1.68-5.4] and improved in 30% and 13.8% (OR=3.9; 95% CI=2.12-7.18) of the "migraine" and "non-migraine" groups, respectively. In the migraine group only, headache episodes occurred predominantly during or around the hormone-free interval (OR=2.05; 95% CI=1.26-3.35). The combination of ethinylestradiol (EE) and drospirenone (DRS) was significantly associated with an improvement in the frequency and/or intensity of migraine-type headaches, compared with other types of COCs.

Conclusions: The prevalence of migraine in COC users appears similar to that found in the general population. Migraines, but not other types of headache, were significantly affected by COCs. The EE/DRS combination was associated with a greater likelihood of improvement in migraine compared with other types of COCs.