Migraine in pregnancy

Migraine does not increase the risk for complications of pregnancy for the mother or for the fetus: the incidences of toxemia, miscarriages, abnormal labour, congenital anomalies, and stillbirths are comparable to those of the general population. Several retrospective studies have shown a tendency for migraine to improve with pregnancy. Between 60 and 70% of women either go into remission or improve significantly, mainly during the second and third trimesters. Women with migraine onset at menarche and those with perimenstrual migraine are more likely to go into remission during pregnancy. The migraine type does not seem to be a significant prognostic factor for improvement. However, in the small number of women (4-8%) whose migraines worsen with pregnancy, migraine with aura appears to be overrepresented. In a small number of cases (1.3-16.5%), migraine appears to start with pregnancy, often in the first trimester; these headaches involve a higher proportion of migraine with aura. Management of migraine during pregnancy should first focus on avoiding potential triggers. Consideration should also be given to nonpharmacologic therapies. If pharmacologic treatment becomes necessary, acetaminophen and codeine can be used safely as abortive agents; ASA and NSAIDs (ibuprofen, naproxen) can be used as a second choice, but not for long periods of time, and they should be avoided during the last trimester. For treatment of severe attacks of migraine, chlorpromazine, dimenhydrinate, and diphenhydramine can be used; metoclopramide should be restricted to the third trimester. According to the United States FDA risk categories, meperidine and morphine show no evidence of risk in humans but should not be used at the end of the third trimester. In some refractory cases, dexamethasone or prednisone can be considered. Should prophylactic treatment become indicated, the beta-adrenergic receptor antagonists (e.g., propranolol) can be used.