Migraine and pregnancy

• Hormonal changes
  • migraine is three times more common in women than in men. Attacks in most women start around puberty and continue until the menopause, with respites during pregnancy
  • migraine is known to be a strongly hormonally mediated disorder, and about 50-75% of pregnant patients with migraine find that their migraine attacks improve during pregnancy (3)
    
• Migraine and pregnancy
  • paracetamol in moderation is safe throughout pregnancy (1)
    • paracetamol is not generally considered to be associated with a significantly elevated risk throughout pregnancy and lactation (4)
  • aspirin and NSAIDs are safe except in the third trimester (1)
  • for nausea, metoclopramide or domperidone are unlikely to cause harm throughout pregnancy and lactation (1)
  • triptans and pregnancy
    • most of the available information relates to sumatriptan, and suggests that exposure during pregnancy leads to no higher risk of birth defects than is recorded in the general population (1)
    • sumatriptan & Naratriptan Pregnancy Registry found no evidence of teratogenicity associated with major birth defects for sumatriptan (4)
    • women who have inadvertently taken triptans and then find themselves pregnant can be reassured that the outcome of the pregnancy is very unlikely to be adversely affected by the triptan. However, since present knowledge is still limited, triptans cannot be recommended as a routine
  • a review noted (3):
    • preventive therapy with calcium channel blockers and with antihistamines may not be associated with adverse fetal or child outcomes; acute therapy with a combination of metoclopramide and diphenhydramine was found to possibly be more effective than codeine; and triptans and low dose aspirin may not be associated with adverse effects in the fetus/child
    • adverse child and fetal outcomes were identified among groups of pregnant patients taking antiepileptics, venlafaxine, tricyclic antidepressants, benzodiazepines, beta blockers, prednisolone, and oral magnesium, although these findings were identified in systematic reviews in which the drugs were studied for indications other than migraine and often at higher doses
    • drug therapy should be evaluated in pregnancy and lactation on a case-by-case basis, with pregnancy and lactation databases serving as guides
      
      
• Migraine and breastfeeding (1)
  • a number of drugs can be used by breastfeeding women to treat migraine. These include the painkillers ibuprofen, diclofenac, and paracetamol, which may be combined with domperidone
  • the manufacturers of almotriptan, eletriptan, frovatriptan and rizatriptan all recommend avoiding breast-feeding for 24 hours after treatment, and the manufacturer of sumatriptan recommends 12 hours, although studies on eletriptan and sumatriptan show that only negligible amounts enter breast milk. In contrast, the manufacturers' advice for naratriptan and zolmitriptan state only "Caution should be exercised when considering administration… to women who are breast-feeding". However, the American Academy of Pediatrics (AAP) Committee on Drugs advises that use of sumatriptan is compatible with breast-feeding
    
    
• ergotamine and dihydroergotamine are contraindicated during pregnancy and lactation (1)

NICE suggest (2):

• acute treatment
  • offer pregnant women paracetamol for the acute treatment of migraine. Consider the use of a triptan or an NSAID after discussing the woman's need for treatment and the risks associated with the use of each medication during pregnancy
  • in November 2015, this was an off-label use of triptans (except nasal sumatriptan) in under 18s
• seek specialist advice if prophylactic treatment for migraine is needed during pregnancy

A review notes (5):

• migraine is a risk factor for hypertensive disorders of pregnancy
  • thus it is important to consult with an obstetrician to exclude preeclampsia when a pregnant woman has a peripartum headache, especially if it is associated with peripheral edema or hypertension.
  • headaches due to migraine are usually less common in the third trimester compared with earlier in pregnancy; therefore, headache in the peripartum period may be concerning
  • other secondary headache disorders in pregnant or postpartum women include
    • cerebral venous thrombosis,
    • pituitary apoplexy,
    • cervical artery dissection, and
    • headache after epidural anesthesia during delivery
• neuroimaging should be considered for patients with
  • abnormal findings on neurologic examination,
  • progressively worsening headache, or
  • an unexplained change in headache pattern
  • MRI is the preferred study for most pregnant women, but head CT is relatively safe during pregnancy and is the study of choice for head trauma and suspected intracranial hemorrhage
    • avoid contrast agents if possible because gadolinium crosses the placental barrier and is excreted by the fetal kidney, although no ill effects to the fetus have been shown

Reference:

• 1) BASH (2010). Guidelines for All Healthcare Professionals in the Diagnosis and Management of Migraine, Tension-Type Headache, Cluster Headache and Medication-Overuse Headache.
• 2) NICE (May 2021). Headaches in the over 12s
• 3) Hovaguimian A, Roth J. Management of chronic migraine BMJ 2022; 379 :e067670 doi:10.1136/bmj-2021-067670
• 4) BASH (2019). National Management System for Adults.
• 5) Niushen Zhang, Matthew S. Robbins. Migraine. Ann Intern Med. [Epub 10 January 2023]. doi:10.7326/AITC202301170