Managing migraine in pregnancy
BMJ 2018; 360 doi: https://doi.org/10.1136/bmj.k80 (Published 25 January 2018) Cite this as: BMJ 2018;360:k80- Sheba Jarvis, specialist registrar training in endocrinology, diabetes and obstetric medicine1,
- Pooja Dassan, consultant neurologist1 2,
- Catherine Nelson Piercy, consultant obstetric physician1 3
- 1Imperial College Healthcare NHS Trust, London W12 0HS, UK
- 2Department of Neurology, Ealing Hospital, London North West Healthcare NHS Trust, Uxbridge Road, Southall UB1 3HW, UK
- 3Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH
- Correspondence to: S Jarvis sheba.jarvis{at}imperial.ac.uk
What you need to know
Exclude more serious causes of headache such as cerebral venous thrombosis before confirming a diagnosis of migraine
Women with premenstrual migraine and migraine without aura are more likely to see an improvement in symptoms during pregnancy
Many therapies for treating and preventing migraines can be safely used in pregnant women
A 36 year old woman who is 17 weeks pregnant with a 15 year history of migraine presents with an episode of a frontal unilateral headache. It is associated with nausea and visual aura consisting of mainly zigzag lines. She says that this headache is similar to her usual migraines, with two other episodes during this pregnancy so far, each lasting for about five or six hours and then resolving. Clinical examination is normal, including blood pressure and urine analysis.
Migraine is one of the commonest neurological complaints in pregnancy, and most affected women either self manage or are managed by non-specialists.1 Many women with a pre-existing history of migraine attacks will see an improvement during pregnancy (particularly those with menstrual related migraine), while those who have migraine with aura are more likely to have an unpredictable course. For a few women, migraine may occur for the first time during pregnancy, which causes anxiety and poses a diagnostic challenge.1 The urgent priority when a patient presents with a headache during pregnancy should be to distinguish primary causes (such as migraine, tension headaches, and cluster headaches) from serious secondary causes. Secondary causes of headaches (such as pre-eclampsia and cerebral venous thrombosis) require urgent assessment and are more likely to occur after 12 weeks gestation (box 1).2
Primary and secondary causes of headaches in pregnancy and important clinical features
Primary causes
Migraine
Tension type headache
Cluster headaches (trigeminal autonomic cephalgias)
Secondary causes
Hypertension or pre-eclampsia
Idiopathic intracranial hypertension
Subarachnoid haemorrhage
Cerebral venous thrombosis
Meningitis
Reversible cerebral vasoconstriction syndrome
Space-occupying lesions
Posterior reversible encephalopathy syndrome
Pituitary diseases (pituitary adenoma, apoplexy, acute Sheehan’s syndrome, lymphocytic hypophysitis)
Other causes of headache—Cervicogenic headaches, medication overuse headaches (patients taking abortive treatment >2-3 times a week), caffeine withdrawal headache, giant cell arteritis (>50 years old), carotid or vertebral dissection, phaeochromocytoma, temporomandibular joint pain, carbon monoxide poisoning, post-epidural puncture headache
What you should cover
Ask about the current pregnancy—date of last menstrual period or dating fetal ultrasound scan to estimate gestation.
Even if the patient has a history of migraine, consider the characteristics of her episodes of migraine before the pregnancy and the nature of her current headache.
Characteristics of migraine before the pregnancy:
Ask her to describe her previous episodes. Were they associated with prodromal symptoms?
Were her attacks related to her menstrual cycle?
What medications did she take as prophylaxis or during an acute attack?
Nature of the current headache:
Assess the onset and character, alterations in headache (such as worsening with posture, coughing, straining, physical exertion, other precipitants)
Ask about factors that improve symptoms, such as avoiding motion or darkness
Tempo of headache, such as time to maximal onset of pain
Are there associated symptoms (including nausea, vomiting, visual symptoms, photophobia, and autonomic features)?
Are there any visual changes? Clarify the nature of any aura. Are these similar to the aura associated with her migraine before pregnancy?
Are there any other focal neurological symptoms?
Are there any cognitive disturbances or changes in behaviour?
Is there any recent head trauma?
Any fevers, rashes, or neck stiffness?
Box 2 lists the clinical features more likely to be associated with migraine.3
Features of headache more likely to be associated with episodic migraine*3
Fully reversible episodes of headache lasting 4-72 hours
Throbbing, unilateral, or bilateral headaches
Recurrent headaches that are moderate to severe
Unusual sensitivity to light or sound; nausea and vomiting
Aura: symptoms can occur with or without headache and
Are fully reversible
Develop over at least 5 minutes
Last 5-60 minutes
Typical aura include visual symptoms (such as flickering lights, spots, lines, partial loss of vision) and sensory symptoms (such as numbness, “pins and needles,” and speech disturbance)
Long history of similar attacks
Well between episodes
No sinister features
May be aggravated by certain activities of daily living
*Episodic migraine is characterised as <15 headache days (days when a headache occurs) per month.
What you should do
Examination
Even though a patient may have a longstanding history of migraine, it is important to rule out any red flag symptoms (box 3)34 and consider any other medical conditions or medications associated with headaches. Measure her blood pressure and conduct urine analysis. Perform a neurological examination, specifically assessing for neck stiffness. Test eye movements, visual fields, and pupillary responses and perform fundoscopy to rule out papilloedema. Refer women with any focal neurological deficits or signs of raised intracranial pressure for urgent intracranial imaging to rule out secondary causes.
Red flag symptoms in a patient with headache in pregnancy (adapted from SIGN and NICE guidelines34) and other considerations
Red flag symptoms
Sudden onset headache reaching maximal intensity in <1 minute
New onset of severe headache or significant changes in headaches
Worsening headache with fever, meningism
Headache triggered by cough, valsalva, sneezing, or exercise suggestive of raised intracranial pressure (drowsiness, diplopia, papilloedema)
Orthostatic headache (changes with posture)
New onset focal neurological deficit, cognitive dysfunction, or seizures
Recent (within the past 3 months) head or neck trauma
Headache with impaired consciousness or personality changes
Headache with unusual aura (duration >1 hour or including motor weakness)
Progressive headache worsening over weeks or months
Visual disturbance or visual field defect
Symptoms suggestive of giant cell arteritis (less relevant to women of childbearing age) or glaucoma
Other considerations
Is the patient hypertensive?
History of neurological conditions, pituitary disease, immunocompromise (such as HIV infection, immunosuppression), malignancy, conditions associated with procoagulable state (such as thrombophilias, antiphospholipid syndrome, polycythaemia, nephrotic syndrome, etc)
Is the patient taking a medication that might cause headaches as a side effect (such as calcium channel antagonists for hypertension in pregnancy)?
Is there a history of medication overuse, typically opioid analgesia?
Is there a family history of intracranial haemorrhage?
Management
When managing a woman with episodic migraine with aura in the context of the second trimester of pregnancy, consider giving the following advice:
Migraine may improve during pregnancy (in about 50-75% of women).5 Improvement typically occurs in the second and and third trimesters
The normal rise in pregnancy hormones (oestrogen levels can be 100-fold higher than outside pregnancy6) can stabilise migraine without aura but has been associated with increased frequency of migraine with aura.
Lack of sleep can precipitate symptoms
Treatments that can be used for migraine are summarised in box 4. Advise non-pharmacological measures in the first instance
First line pharmacological measures for an acute attack include simple analgesia such as paracetamol.7 Antiemetics can be used to relieve symptoms of nausea and vomiting
Women with migraine in pregnancy may be at increased risk of pre-eclampsia, gestational hypertension, arterial and venous thrombosis.89 Explain the symptoms that might signify this and encourage attendance at regular antenatal checks with monitoring of blood pressure and urine.
Strategies in the prophylaxis and treatment of migraine in pregnancy
Non-pharmacological strategies58
Hydrate with a minimum of 2 litres of water per day
Avoid skipping meals
Reduce caffeine intake but avoid sudden withdrawal (caffeine withdrawal headaches can occur in patients with consumption of >200 mg/day for >2 weeks, when suddenly interrupted)
Sleep hygiene—Avoid bright lights and mobile phone use; have appropriate amount of sleep (7-8 hours a night)
Regular exercise
Behavioural medicine strategies—Such as biofeedback and relaxation therapy, non-invasive stimulation devices (transcutaneous supraorbital nerve stimulation)10
Treating migraine
First line analgesia—paracetamol (acetaminophen)7
Avoid opiates—Although they are considered safe, they can exacerbate nausea and reduce gastric motility. Chronic use increases the risk of medication overuse headache
If required, consider ibuprofen, although it has less safety data than paracetamol (avoid in third trimester because of risk of premature closure of ductus arteriosus)71112
Antiemetics such as prochlorperazine, cyclizine (first line), domperidone, ondansetron, and metoclopramide are safe to use in pregnancy. Avoid long term use of metoclopramide because of its extrapyramidal side effects13
Greater occipital nerve block can alleviate pain and reduce the number of headache days and medication consumption14
For severe intractable migraine, consider serotonin receptor agonists such as sumatriptan, which has not been shown to be associated with adverse outcome715
Do not use topiramate and sodium valproate as they are teratogenic,78 and avoid ergotamines in pregnancy18
Migraine prophylaxis
Aspirin 75 mg once a day is often helpful for migraine prevention in pregnancy. Low dose aspirin has been used safely until 36 weeks’ gestation in a recent randomised controlled trial16
β Blockers such as low dose propanolol (10-40 mg three times a day) can be used, and once a day preparations can facilitate adherence.15817 Historical concerns about effects on fetal growth from β blockers are from studies which often used higher doses and studied hypertensive mothers or those with cardiac diseases where it is difficult to differentiate the drug effects from underlying condition. Recent studies show use in the first trimester of pregnancy is not associated with a higher risk of specific congenital anomalies18
Low dose tricyclic antidepressants such as amitriptyline 10-25 mg taken at night can be considered1119
Education into practice
Do you feel confident prescribing treatments for migraine in your pregnant patients?
Professional UK guidelines and resources on headache
Scottish Intercollegiate Guidelines Network. Diagnosis and management of headache in adults, a national clinical guideline (publication No 107). 2008. www.sign.ac.uk/guidelines/fulltext/107/index.html
National Institute of Health and Care Excellence. Headaches in over 12s: diagnosis and management (clinical guideline 150). 2016. www.nice.org.uk/guidance/cg150
National Institute of Health and Care Excellence. Headaches overview. https://pathways.nice.org.uk/pathways/headaches
How were patients involved in the creation of this article
We sought comments from patients who have had migraine during the pregnancy. Patients felt that, since there are many causes of headache in pregnancy, reassurance from the doctor (after ruling out more serious causes) and a simple explanation about migraine in pregnancy can reduce patient stress. In particular, the patients consulted felt the issue of medication safety in pregnancy was important.
Footnotes
This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.
Contributors: SJ and CNP conceived and contributed to the work. SJ drafted the work, PD and CNP revised it critically. All authors approved the final version for publication and accept full responsibility for the published article. CNP is the guarantor.
Competing interests: We have read and understood the BMJ policy on declaration of interests and have no relevant interests to declare.
Provenance and peer review: Not commissioned; externally peer reviewed.