Migraine in Pregnancy

Migraine in pregnancy is recurrent throbbing headache with nausea, light sensitivity and sometimes aura, in a pregnant woman. Most women improve in pregnancy, especially from the second trimester, while new or worsening headache needs urgent assessment. It matters because migraine with aura raises the risk of stroke and preeclampsia, and many drugs must be changed.

• Risk factors for worsening: aura, first trimester, previous menstrual migraine, poor sleep.
• Most attacks can be managed with paracetamol and metoclopramide.
• Headache with hypertension is preeclampsia until proven otherwise.

Women have unilateral throbbing headache lasting 4 to 72 hours, with nausea, vomiting, photophobia, phonophobia and sometimes visual aura, and a normal neurological examination between attacks. Check blood pressure, fundi and neurology at each visit.

• Aura develops over 5 to 60 minutes.
• Pain worsens with activity.
• Differential diagnosis: tension headache, preeclampsia, cerebral venous thrombosis, stroke, subarachnoid haemorrhage, meningitis, idiopathic intracranial hypertension, pituitary tumour, caffeine withdrawal.
• Complications: dehydration, medication overuse headache, ischaemic stroke, preeclampsia, postpartum worsening.

The diagnosis is clinical, with tests when red flags are present.

• Blood pressure and urine protein at each visit.
• Full blood count, glucose, electrolytes, malaria test where relevant.
• Brain MRI without gadolinium, or CT with shielding, for new focal signs, thunderclap onset or papilloedema.
• Lumbar puncture if meningitis or subarachnoid haemorrhage is suspected.

The principle is simple analgesia early, avoid harmful drugs and look for secondary causes.

• Supportive: rest in a dark quiet room; fluids; regular meals and sleep; avoid triggers such as caffeine excess, alcohol and fasting; magnesium rich foods; cold compress.
• Pharmacological: paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) at the start of the attack; metoclopramide 10 mg oral or IV 8-hourly (maximum 5 days); for moderate to severe attacks add sumatriptan 50 mg oral, repeated once after 2 hours (maximum 200 mg in 24 hours); ibuprofen 400 mg oral 8-hourly only before 20 weeks and for no more than 3 days; for frequent attacks give prophylaxis with propranolol 10 to 40 mg oral 12-hourly or amitriptyline 10 to 25 mg oral at night, with magnesium oxide 400 mg oral daily; avoid ergotamine, valproate, topiramate, codeine overuse and aspirin at analgesic doses.
• Procedures: none.
• Special groups: women with aura avoid combined hormonal contraception; women with preeclampsia or secondary headache are managed for the underlying cause; breastfeeding is compatible with paracetamol, sumatriptan and propranolol.
• Red flags: thunderclap headache, headache with blood pressure above 140/90 mmHg, new neurological deficit, fever with neck stiffness, seizure, visual loss, headache first appearing after 20 weeks.
• Follow-up: headache diary; review every 4 weeks; review at 6 weeks postpartum.