Oral contraceptives and increased headache prevalence: the Head-HUNT Study.

Abstract

To examine the prevalence of headache and migraine among women using oral contraceptives (OCs) in a large, cross-sectional population-based study. In the Nord-Trøndelag Health Study in Norway 1995-1997 (HUNT 2), 27,700 (60%) out of 46,506 invited women responded to headache questions (Head-HUNT). Among 14,353 premenopausal women, 13,944 (97%) responded to questions regarding use of contraceptives. There was a significant association between headache and reported use of estrogen-containing OCs in premenopausal women, both for migraine (OR = 1.4, 95% CI = 1.2 to 1.7) and for non-migrainous headache (OR = 1.2, 95% CI = 1.0 to 1.4). A significant dose relationship between headache and the amount of estrogen in the OCs could not be demonstrated. No significant association between headache and OCs containing only gestagen was found. Headache, especially migraine, was more likely among premenopausal women using oral contraceptives containing estrogen.