The fact that menstrual migraine (MM) is associated with estrogen withdrawal prompts a question: What happens immediately postpartum, when estrogen levels decline with loss of the placenta?
Although hormonal fluctuations generally stabilize during pregnancy, and most menstrual migraineurs experience fewer headaches during gestation, that protective effect erodes at delivery, when the incidence of migraine can be as high as 40% in the first week.41
Investigators who prospectively studied 49 migraineurs—two of whom were affected by migraine with aura and 47 by migraine without aura—found improvement in 46.8% of these women during the first trimester of pregnancy, 83% during the second trimester, and 87.2% during the third trimester, with complete remission rates of 10.6%, 53.2%, and 78.7%, respectively.42 During the first postpartum week, migraine recurred in 34% of women.42 Interestingly, women who had a history of MM were less likely to improve during the first and third trimesters of pregnancy.42
In a separate prospective investigation of 985 women who delivered over a 3-month period in one tertiary-care facility, 381 experienced postpartum headache.43 The median time to onset of the headache was 2 days, and the median duration was 4 hours. More than 75% of these headaches were primary headaches.43 Only a small percentage (4%) were incapacitating.43
When migraine may signal a more serious condition
Another question arises when a woman experiences a severe headache shortly after delivery: Could the headache be related to preeclampsia or another serious complication of pregnancy and delivery? According to Contag and colleagues, immediate assessment may be warranted.44
“Characteristics to consider are the association of the headache with elevated blood pressure (which could signal postpartum preeclampsia), the sudden onset of an atypical headache, and variations to the usual nature of the migraine, such as the onset of new neurological symptoms. Postpartum women with any of these characteristics should be evaluated in the emergency department, and neuroimaging should be strongly considered,” they write.44
Treatment reverts to prepregnancy options
Assuming preeclampsia or another serious condition is not the culprit, the treatment options for postpartum migraine revert to prepregnancy choices, as effect on the developing fetus is no longer a concern. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the first line of therapy. If they are ineffective, proceed to an ergotamine or triptan.—Janelle Yates, Senior Editor
Nonhormonal (nonspecific) therapy NSAIDs may provide some relief. In one small study, naproxen sodium (550 mg twice daily) was administered for 2 weeks, beginning 1 week before the anticipated onset of menses. It modestly reduced the overall duration and severity of menstrual migraine16—a benefit that must be weighed against the risk of adverse events and the more recent FDA black box warning about its potentially serious heart and gastrointestinal risks.
Triptan regimens may prevent MM. Several triptans have been investigated for prevention of MM. A small, open-label study evaluated the use of oral sumatriptan (25 mg three times daily), beginning 2 to 3 days before the anticipated onset of MM and continuing for 5 days.17 Menstrual attacks were prevented in just over 50% of cases.
Naratriptan (1 mg twice daily), beginning 2 days before anticipated menses and continuing for 5 days, reduced the number of MM attacks by 50%, with side effects comparable to placebo.18 A higher dosage (2.5 mg twice daily) did not prove to be superior to placebo, for unexplained reasons.
In a similar trial, frovatriptan (2.5 mg daily or 2.5 mg twice daily), beginning 2 days before the anticipated onset of MM and continuing for 6 days, prevented at least 50% of MM.19 Twice-daily dosing was superior to daily administration.
Magnesium may shorten MM. In one small study, oral magnesium (360 mg daily), beginning on the 15th day of the cycle and continuing through the menses, shortened the duration of MM and improved menstrual complaints better than placebo.20
The goal of hormonal therapy is to eliminate or sufficiently minimize the premenstrual decline in estrogen that is believed to precipitate MM.21 An observational study of 229 women found that hormonal strategies prevented MM in 73% of cases (81% when taken as directed).22
It is fortunate that MM, by definition, is migraine without aura, because the use of combined OCs has been controversial in the setting of migraine with aura. International studies have reported a small but increased risk of stroke associated with their use, although a subset of women with migraine had no increased risk.23-25 In contrast, no U.S. study since 1975 has found an increased risk of stroke associated with the use of OCs.26 One large domestic study reviewed 3.6 million woman-years of use and found no increased risk of ischemic stroke with the low-dose OCs currently available, nor did a pooled analysis of U.S. studies.27,28