Oral contraceptives in women with migraine: balancing risks and benefits.

Oral contraceptives (OCs) are a safe and highly effective method of birth control, but can also be associated with some risks, mainly a potential thrombotic risk. OCs may condition the course of headache and sometimes start it, but their influence on the clinical evolution of migraine is not easily assessable. The last Classification of Headache Disorders of the International Headache Society clearly identifies an "exogenous hormone-induced headache" that could be triggered by intake of OCs. Old high-dose OCs could effectively worsen headache in a significant proportion of patients, but the newest formulations influence headache course to a lesser extent. In any case, while an increase in migraine frequency or intensity do not oblige the cessation of OCs, experiencing a migraine aura for the first time, or even a clear worsening of a preexistent aura suggest discontinuation of OCs. Even if both migraine and OCs intake are associated with an increased risk of ischaemic stroke, migraine per se is not a contraindication for OCs use; however, patients suffering from migraine with aura generally show a greater thrombotic risk than women with migraine without aura. Other risk factors (patient's age, tobacco use, hypertension, hyperlipidaemia, obesity and diabetes) must be carefully considered when prescribing OCs in migraine patients. Furthermore, all OCs, even those with low oestrogen content, are a major risk for venous thrombosis, particularly in women with hereditary thrombophilia. A thorough laboratory control of the genetics of prothrombotic factors and coagulative parameters should precede any decision of OCs prescription in migraine patients.