Of the more than 37 million Americans who suffer from migraine, the majority are women. The estimated overall prevalence of migraine is 18% in women and 6% in men, and the rate is as high as 37% among women during the reproductive years.1,2 The sizable difference between the sexes is largely attributed to hormonal differences.
“There are certainly relationships between migraine and hormones in women, and this is most pronounced in the fact that migraine in women often develops after they reach puberty, may worsen with menses, and change during pregnancy and again with menopause,” Mia T. Minen, MD, MPH, assistant professor of neurology and director of Headache Services at New York University Langone Medical Center in New York City, told Neurology Advisor. In fact, prevalence rates are similar in both sexes until puberty, and they increase in women after menarche.3 “It seems clear that certain hormonal changes that occur during puberty in girls, and remain throughout adulthood, are implicated in the triggering and frequency of migraine attacks in women,” said Huma U. Sheikh, MD, an assistant professor of neurology at Mount Sinai Beth Israel in New York City.
“Many women notice that they tend to have headaches a day or two before their monthly menstruation. This is thought to be due to the dramatic drop in estrogen prior to its onset,” Dr Sheikh told Neurology Advisor. An estimated 60% of women with migraine regularly experience menstrual migraine. Migraine without aura (MwA) occurs most frequently in the 2 days before and 3 days following the start of menstruation, and migraine attacks during this time have been found to be more severe, longer-lasting, and more treatment-resistant than attacks experienced at other points in the menstrual cycle.3 Notably, migraine with aura is not typically associated with menstruation, and even in patients who experience migraine with aura at other points in the reproductive cycle, aura rarely accompanies the attacks they experience during menstruation.
When migraine occurs exclusively during this 5-day time frame, it is called pure menstrual migraine, although this tends to affect less than 10% to 20% of women with migraine.3 More commonly, such patients have additional migraine attacks, with or without aura, throughout the menstrual cycle. Although research does not support an association between migraine and ovulation, some women do report getting headaches at that point in their cycle, Dr Sheikh noted.
Likely because of increased estrogen levels, more than half of women with migraine experience fewer attacks during pregnancy, according to a review published in Current Neurology and Neuroscience Reports in April 2016.4 “This seems to be even more so for women with a prior history of menstrually related migraines,” said Dr Minen. “Even with this improvement, the majority of migraine patients will still suffer migraines at some point during pregnancy, and some experience worsened migraines, especially in the first trimester.”
Women with a history of migraine have a greater risk of adverse outcomes during pregnancy, including pre-eclampsia, preterm birth, ischemic stroke, acute myocardial infarction, and heart disease, and thromboembolic events, according to Dr Minen. Patients with migraine also generally have higher rates of insomnia, and this poor sleep quality is worse during pregnancy. A recent study in which Dr Minen was a co-investigator, which was presented in 2016 at both the American Headache Society meeting and the European Headache and Migraine Trust International Congress, showed that 49.2% of patients presenting to headache clinics with suspected migraine had a positive insomnia screen.5