The occurrence of migraine in women is influenced by hormonal changes throughout the lifecycle. A beneficial effect of pregnancy on migraine, mainly during the last 2 trimesters, has been observed in 55 to 90% of women who are pregnant, irrespective of the type of migraine. A higher percentage of women with menstrual migraine find that their condition improves when they are pregnant. However, in rare cases migraine may appear for the first time during pregnancy. The positive effects of pregnancy on migraine and the possible worsening post partum are probably related to the uniformly high and stable estrogen levels during pregnancy and the rapid fall-off thereafter. Nondrug therapies (relaxation, sleep, massage, ice packs, biofeedback) should be tried first to treat migraine in women who are pregnant. For treatment of acute migraine attacks 1000 mg of paracetamol (acetaminophen) preferably as a suppository is considered the first choice drug treatment. The risks associated with use of aspirin (acetylsalicylic acid) and ibuprofen are considered to be small when the agents are taken episodically and if they are avoided during the last trimester of pregnancy. The 'triptans' (sumatriptan, zolmitriptan, naratriptan), dihydroergotamine and ergotamine tartrate are contraindicated in women who are pregnant. Prochlorperazine for treatment of nausea is unlikely to be harmful during pregnancy. Metoclopramide is probably acceptable to use during the second and third trimester. Prophylactic treatment is rarely indicated and the only agents that can be given during pregnancy are the beta-blockers metoprolol and propranolol.