Headache in pregnancy and postpartum

Headache in pregnancy and the postpartum period is head pain starting or worsening between conception and 6 weeks after birth.

Most headaches are primary (tension type or migraine). The period carries a higher risk of dangerous secondary causes: pre eclampsia and eclampsia, cerebral venous thrombosis, stroke, subarachnoid haemorrhage, reversible cerebral vasoconstriction syndrome, posterior reversible encephalopathy syndrome, and post dural puncture headache after neuraxial anaesthesia.

A new or changed headache after 20 weeks, or in the first 6 weeks after birth, is pre eclampsia until proved otherwise. Red flags should lead to blood pressure measurement, urinalysis, neurological examination and imaging without delay.

Clinical relevance. Headache is a common symptom and the usual reason for pre eclampsia to be identified. Pre eclampsia can first appear after birth, up to 6 weeks, with blood pressure peaking between days 3 and 6.

Physiology. Pregnancy changes cerebral blood flow autoregulation, coagulation (hypercoagulable), and hormone levels. Migraine often improves in the second and third trimesters and may relapse in the postpartum period when oestrogen falls. Plasma volume expands by 40 to 50% and blood pressure falls in the second trimester.

Mechanisms.

• Hypertensive encephalopathy and endothelial dysfunction (pre eclampsia).
• Venous outflow obstruction (thrombosis).
• Cerebral vasospasm (reversible cerebral vasoconstriction).
• Vessel rupture (aneurysm or malformation).
• Loss of cerebrospinal fluid after dural puncture (traction on pain sensitive structures).
• Raised intracranial pressure.
• Tumour growth under hormonal stimulation.

Classification.

Primary headaches: tension type, migraine with and without aura, cluster headache. Secondary headaches: hypertensive disorders, vascular, intracranial pressure related, infection, structural, metabolic and drug related.

Timing: first trimester (migraine, caffeine withdrawal, sinusitis, dehydration), second half of pregnancy (pre eclampsia, venous thrombosis, intracranial hypertension), postpartum (pre eclampsia, post dural puncture headache, venous thrombosis, vasoconstriction, pituitary disorders).

Key distinctions. A sudden maximal headache within seconds (thunderclap) needs imaging for haemorrhage and vasoconstriction. A positional headache worse upright suggests post dural puncture headache or low intracranial pressure. A progressive headache with papilloedema suggests raised pressure. A headache with hypertension, proteinuria, visual symptoms or epigastric pain suggests pre eclampsia.

History

• Gestation or days since birth, onset (sudden, gradual), peak, duration, site, quality, severity, pattern (daily, episodic), timing (morning, nocturnal), triggers (cough, strain, exertion, sex), posture effect.
• Associated: visual disturbance (blurring, scotomata, flashing lights, diplopia), nausea and vomiting, photophobia, phonophobia, aura, neck stiffness, fever, rash, seizures, confusion, focal weakness, speech change, ear or eye pain, jaw claudication.
• Pre eclampsia symptoms: epigastric or right upper quadrant pain, swelling of face and hands, reduced foetal movements, breathlessness.
• Obstetric: hypertension in this or previous pregnancy, pre eclampsia, multiple pregnancy, neuraxial anaesthesia (epidural, spinal, accidental dural puncture), caesarean section, postpartum haemorrhage, infection.
• Medical history: migraine, hypertension, epilepsy, thrombophilia, antiphospholipid syndrome, intracranial aneurysm or malformation, polycystic kidney disease, pituitary disease, idiopathic intracranial hypertension, sinus disease, head injury, cancer.
• Drugs: caffeine, analgesic overuse (over 10 to 15 days each month), triptans, ergot derivatives, bromocriptine, cabergoline, selective serotonin reuptake inhibitors, nifedipine, nitrates, oral contraceptive history, cocaine and amphetamines, alcohol.
• Environment: carbon monoxide exposure (heaters, generators), hunger, sleep loss, dehydration.
• Social: stress, depression, domestic abuse, head trauma.

Examination

• Vital signs: blood pressure measured with the correct cuff size and repeated after 15 minutes if raised; pulse, temperature, respiratory rate, oxygen saturation, glucose.
• General: pallor, rash, jaundice, oedema, breath odour.
• Neurological: level of consciousness, cranial nerves, visual acuity and fields, fundoscopy (papilloedema, retinal haemorrhage, venous pulsation), pupils, eye movements, limb power, tone, reflexes (brisk reflexes and clonus in pre eclampsia), plantar responses, gait, meningism.
• Head and neck: sinus tenderness, temporal artery tenderness, cervical tenderness, ear, teeth.
• Back: epidural insertion site (infection, haematoma, tenderness).
• Obstetric: fundal height, foetal heart, uterine tone, lochia and breasts postpartum.
• Bedside tests: urine dipstick for protein, glucose, ketones; capillary glucose; peak flow when relevant.

Red flags

• Blood pressure of 140/90 mmHg or more after 20 weeks or in the postpartum period, especially with headache, visual disturbance, epigastric pain, clonus, or proteinuria.
• Severe hypertension (160/110 mmHg or more).
• Thunderclap onset, worst headache of life, or headache with exertion, sex or straining.
• Seizure, confusion, reduced consciousness, focal deficit or papilloedema.
• Fever with neck stiffness, rash or photophobia.
• New headache in a woman over 40 years, or a change from usual pattern.
• Positional worsening with severe orthostatic headache after neuraxial anaesthesia and neurological signs.
• Recent postpartum haemorrhage with lactation failure (Sheehan syndrome), visual field loss (pituitary lesion).
• Immunosuppression, HIV, malignancy, anticoagulation.
• Systemic symptoms such as weight loss and night sweats.
• Pregnancy with thrombophilia, dehydration, sepsis or caesarean section (venous sinus thrombosis).

Special groups. Postpartum women: pre eclampsia and post dural puncture headache are most common. Women with migraine with aura: increased stroke risk and avoidance of oestrogen containing contraception. Women who are breastfeeding: choice of analgesia and prophylaxis changes. Region specific: malaria, meningitis, cysticercosis, tuberculosis and HIV related infections.

Organised by mechanism. Each cause is common unless marked serious or uncommon. Primary headaches

• Tension type headache.
• Migraine with or without aura (may begin in pregnancy, or change with hormones).
• Cluster headache (uncommon).
• Medication overuse headache, caffeine withdrawal headache.
• Hypnic headache, cough headache and exertional headache (uncommon).

Hypertensive disorders

• Serious: pre eclampsia and eclampsia.
• Serious: HELLP syndrome.
• Serious: posterior reversible encephalopathy syndrome.
• Hypertensive emergency from chronic hypertension, phaeochromocytoma, renal disease.
• Postpartum pre eclampsia.

Vascular

• Serious: cerebral venous thrombosis.
• Serious: subarachnoid haemorrhage (ruptured aneurysm, arteriovenous malformation).
• Serious: intracerebral haemorrhage.
• Serious: ischaemic stroke, cervical artery dissection, reversible cerebral vasoconstriction syndrome.
• Serious: pituitary apoplexy, Sheehan syndrome, lymphocytic hypophysitis.
• Cerebral vasculitis, moyamoya disease.
• Pregnancy specific: peripartum angiopathy and postpartum cerebral angiopathy.
• Thrombotic thrombocytopenic purpura, antiphospholipid syndrome.

Intracranial pressure related

• Post dural puncture headache, spontaneous intracranial hypotension.
• Idiopathic intracranial hypertension.
• Serious: intracranial tumour (meningioma growth, pituitary adenoma, glioma, metastasis), hydrocephalus, abscess.

Infection

• Serious: bacterial meningitis (including Listeria), viral meningitis, encephalitis (herpes simplex), cerebral abscess, malaria, tuberculous meningitis, cryptococcal meningitis in HIV, neurocysticercosis.
• Sinusitis, otitis media, dental abscess.
• Influenza and other viral illness, urinary tract infection.

Metabolic and toxic

• Serious: carbon monoxide poisoning.
• Hypoglycaemia, dehydration, anaemia, hyperthyroidism, hypothyroidism, hypercapnia.
• Drug related: vasodilators, selective serotonin reuptake inhibitors, ergots, bromocriptine, cocaine, alcohol withdrawal.

Musculoskeletal and others

• Cervicogenic headache, temporomandibular disorder, poor posture, eye strain and refractive error.
• Trigeminal neuralgia, giant cell arteritis (uncommon).
• Acute angle closure glaucoma (rare), optic neuritis.
• Depression, anxiety, sleep deprivation.

Stepwise reasoning

1. Measure blood pressure and test urine in every pregnant or postpartum woman with headache.
2. Classify the headache by onset, pattern and associated features, and look for red flags.
3. Treat severe hypertension and prevent seizures before further tests if pre eclampsia is present.
4. Image the brain when there is a red flag, focal sign, thunderclap onset, persistent unexplained headache, or a failure of treatment.
5. Choose the imaging by cause: CT head (with CT angiography) for haemorrhage; MRI with venography for venous thrombosis, posterior reversible encephalopathy, and tumour; MR angiography for vasoconstriction.
6. Perform lumbar puncture after imaging when meningitis, subarachnoid haemorrhage with negative CT, or raised pressure are possible.

First line tests

• Blood pressure (repeat), urine protein (dipstick, then protein to creatinine ratio over 30 mg/mmol or 24 hour protein over 0.3 g).
• Full blood count (platelets under 100 x 10^9/L), urea, creatinine, electrolytes, liver function tests (aspartate or alanine aminotransferase over 70 IU/L), lactate dehydrogenase (over 600 IU/L), uric acid, glucose, coagulation screen with fibrinogen, haemolysis screen.
• Pre eclampsia is defined by blood pressure 140/90 mmHg or more after 20 weeks (or postpartum), plus new proteinuria or evidence of maternal organ or uteroplacental dysfunction.
• Organ or uteroplacental dysfunction includes raised creatinine, liver involvement, thrombocytopenia, neurological features, pulmonary oedema, and foetal growth restriction.
• Blood cultures, C reactive protein, malaria test and HIV test as indicated.
• Thyroid function and calcium if clinical indicators.
• Carboxyhaemoglobin by blood gas if carbon monoxide exposure is possible.
• Cardiotocography and ultrasound for foetal wellbeing.

Neuroimaging

• CT head without contrast: sensitivity for subarachnoid haemorrhage is near complete if done within 6 hours of onset by a modern scanner and read by an experienced radiologist; it falls after that.
• The foetal dose from a head CT is negligible with abdominal shielding, and imaging should not be withheld.
• CT angiography or MR angiography for aneurysm, dissection and vasoconstriction.
• MRI of the brain with MR venography (without gadolinium) for cerebral venous thrombosis, posterior reversible encephalopathy syndrome (vasogenic oedema in posterior regions on T2 and FLAIR), stroke, tumour, pituitary pathology. CT venography is an alternative.
• Gadolinium is avoided in pregnancy unless the benefit clearly exceeds the risk.
• Lumbar puncture: opening pressure (over 25 cm of water in idiopathic intracranial hypertension; low in intracranial hypotension), cell count, protein, glucose.
• Check xanthochromia by spectrophotometry at 12 hours or more from onset when CT is negative and subarachnoid haemorrhage is suspected.
• Check platelets and coagulation before lumbar puncture, and delay if anticoagulated.

Targeted tests

• Cerebrospinal fluid culture, polymerase chain reaction for herpes simplex virus, cryptococcal antigen, and acid fast bacilli as indicated.
• Pituitary hormones (cortisol, thyroid stimulating hormone, free thyroxine, prolactin) when pituitary disease is suspected.
• Antiphospholipid antibodies and thrombophilia screen (not valid during acute thrombosis or anticoagulation for some tests).
• Echocardiography when stroke is suspected (peripartum cardiomyopathy, paradoxical embolism).
• Ophthalmology review for visual change and papilloedema.
• Urine drug screen when appropriate.

Limitations. Headache severity does not reflect the cause. Pre eclampsia can occur with a blood pressure under 140/90 mmHg at presentation, or without proteinuria. CT misses venous thrombosis and posterior reversible encephalopathy. Early MRI may be normal in reversible vasoconstriction. Lumbar puncture is not valid when platelets are low or the woman is anticoagulated.

Immediate steps. Ensure airway and circulation, give oxygen if saturation is under 94%, check glucose, establish intravenous access, and measure blood pressure. Treat seizures and severe hypertension urgently. Place the woman in the left lateral position after 20 weeks. Call senior obstetric, anaesthetic and neurology help for red flag features.

Severe hypertension and eclampsia

• Severe hypertension is 160/110 mmHg or more, confirmed over 15 minutes. Reduce blood pressure in 30 to 60 minutes to systolic 140 to 150 mmHg and diastolic 90 to 100 mmHg.
• Labetalol 200 mg orally, repeated once after 30 minutes if needed.
• Alternatively give intravenous labetalol 20 mg over 2 minutes, then 40 mg, 80 mg and 80 mg at 10 minute intervals (maximum total 220 mg). Or use an infusion starting at 20 mg/h and doubling every 30 minutes to a maximum of 160 mg/h.
• Avoid labetalol in asthma, heart block and acute heart failure. Maintenance: 200 mg orally two to three times daily (maximum 2400 mg daily).
• Nifedipine immediate release 10 mg orally, repeated after 30 minutes (maximum 30 mg in the first hour; not sublingual); then modified release 10 to 20 mg orally twice daily (maximum 80 mg daily).
• Hydralazine 5 mg intravenously over 5 to 10 minutes, repeated at 20 minutes (maximum 20 mg), with a risk of foetal heart rate abnormality and maternal tachycardia.
• Magnesium sulphate for eclampsia and for severe pre eclampsia: 4 g intravenously over 5 to 15 minutes, then 1 g/h for 24 hours after the last seizure or birth. For a further seizure give 2 g over 5 minutes.
• Check respiratory rate (over 12 breaths/min), oxygen saturation, patellar reflexes and urine output (over 0.5 mL/kg/h) at least hourly.
• In renal impairment check serum magnesium (usual range 2 to 4 mmol/L) and reduce the maintenance to 0.5 g/h. Antidote: calcium gluconate 10% 10 mL (1 g) intravenously over 10 minutes.
• Delivery is the definitive treatment for pre eclampsia and is decided by gestation and severity. Give corticosteroids (betamethasone 12 mg intramuscularly twice, 24 hours apart) before 34 weeks if delivery is not immediate.
• Postpartum: continue antihypertensives and monitoring, with blood pressure checked at least daily for the first days.
• Enalapril 5 mg orally once daily (increase to 20 mg twice daily) is acceptable during breastfeeding; nifedipine, labetalol and amlodipine are acceptable.
• Furosemide 20 to 40 mg orally once daily for 3 to 5 days can reduce blood pressure in postpartum pre eclampsia.

Primary headache: tension type and migraine

• Paracetamol 1 g orally every 4 to 6 hours, maximum 4 g daily (3 g daily with chronic alcohol use, malnutrition or hepatic impairment; 15 mg/kg each dose under 50 kg). First line in pregnancy and breastfeeding.
• Metoclopramide 10 mg orally, intramuscularly or intravenously, maximum 30 mg daily and for no more than 5 days; prochlorperazine 10 mg orally or 12.5 mg intramuscularly or intravenously, maximum 40 mg daily.
• Ibuprofen 400 mg orally every 6 to 8 hours with food, only in the postpartum period and during the second trimester before 20 weeks; avoid NSAIDs from 20 weeks of pregnancy.
• Sumatriptan 50 to 100 mg orally at onset (may repeat once after 2 hours; maximum 300 mg daily), or 6 mg subcutaneously (maximum 12 mg daily). It is acceptable in pregnancy if the other drugs have failed, and compatible with breastfeeding. It is contraindicated with uncontrolled hypertension, coronary artery disease, and stroke.
• Avoid ergot derivatives (uterotonic) and codeine during breastfeeding.
• Preventive treatment for frequent migraine: propranolol 40 mg orally two to three times daily (maximum 240 mg daily; monitor foetal growth and neonatal heart rate); amitriptyline 10 to 25 mg orally at night (maximum 75 mg daily). Avoid topiramate and valproate (teratogenic) and ACE inhibitors.
• Non drug measures: sleep, hydration, regular meals, dark room, and cold compress.
• Greater occipital nerve block with lidocaine 2% 2 to 3 mL (maximum 4.5 mg/kg plain lidocaine) for severe refractory migraine.
• Cluster headache: oxygen 100% 12 L/min by non rebreather mask for 15 minutes, and sumatriptan 6 mg subcutaneously.

Post dural puncture headache

• Typical onset 24 to 48 hours after puncture (range 1 to 5 days), worse sitting up, relieved by lying flat, with neck stiffness, tinnitus and photophobia.
• Conservative: lie flat for comfort, hydration, paracetamol 1 g every 6 hours, caffeine 300 mg orally (evidence limited; compatible with breastfeeding).
• Epidural blood patch: autologous blood 15 to 20 mL, after 24 to 48 hours from puncture, for severe or persistent headache; avoid with sepsis, bacteraemia and coagulopathy.
• Sphenopalatine ganglion block or greater occipital nerve block as alternatives.
• Investigate for subdural haematoma or venous thrombosis if the headache changes character or neurological signs appear.

Cerebral venous thrombosis.

• Therapeutic enoxaparin 1 mg/kg subcutaneously every 12 hours (reduced to 1 mg/kg once daily for creatinine clearance under 30 mL/min), even with haemorrhagic infarction.
• Continue through pregnancy and for at least 6 weeks after birth (minimum total 3 to 6 months).
• Levetiracetam 500 mg twice daily (maximum 3 g daily) for seizures. Manage raised intracranial pressure with head elevation.
• Warfarin is acceptable after birth including during breastfeeding; avoid direct oral anticoagulants. Endovascular therapy for deterioration.

Subarachnoid haemorrhage. Resuscitate, give nimodipine 60 mg orally every 4 hours for 21 days (monitor blood pressure, reduce to 30 mg every 2 hours if hypotensive), and arrange urgent neurosurgical or neuroradiological treatment (coiling or clipping). Plan delivery together with obstetric and neurosurgical teams.

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome. Stop vasoactive drugs (ergot derivatives, selective serotonin reuptake inhibitors, triptans, bromocriptine) and control blood pressure. Give magnesium sulphate in eclampsia. Give nimodipine 30 to 60 mg orally every 4 hours for vasoconstriction (evidence limited), and avoid corticosteroids in vasoconstriction. Repeat imaging in 1 to 3 weeks.

Idiopathic intracranial hypertension. Opening pressure over 25 cm of water. Weight management, therapeutic lumbar puncture, acetazolamide 250 mg orally twice daily after the first trimester if needed (maximum 4 g daily; avoid in the first trimester), and ophthalmology review. Optic nerve sheath fenestration or cerebrospinal fluid shunt for progressive visual loss.

Meningitis and encephalitis. Give ceftriaxone 2 g intravenously every 12 hours with amoxicillin 2 g intravenously every 4 hours (covers Listeria) and dexamethasone 10 mg intravenously every 6 hours for 4 days, started before or with the first antibiotic dose. Give aciclovir 10 mg/kg intravenously every 8 hours (adjust for renal function) for suspected herpes encephalitis. Lumbar puncture, but do not delay antibiotics.

Pituitary apoplexy and Sheehan syndrome. Hydrocortisone 100 mg intravenously, then 50 mg every 6 hours, with urgent neurosurgical review for visual loss, and endocrine replacement.

Carbon monoxide poisoning. High flow oxygen 100% until carboxyhaemoglobin is under 3%; hyperbaric oxygen is used in pregnancy for neurological signs, loss of consciousness, or foetal compromise.

Special groups. Breastfeeding: paracetamol, ibuprofen, sumatriptan, propranolol and amitriptyline are compatible; avoid codeine and ergot derivatives. Women with migraine with aura: avoid oestrogen containing contraception after birth. Chronic hypertension: continue labetalol or nifedipine and avoid ACE inhibitors and angiotensin receptor blockers in pregnancy.

Monitoring. Blood pressure every 15 minutes during acute treatment, then hourly, and at least 4 times daily after stabilisation; fluid balance; neurological observations every 1 hour; cardiotocography; magnesium toxicity checks; and daily bloods in HELLP syndrome. Repeat imaging when clinically required.

Referral and escalation. Refer the same day to the obstetric team for any new headache after 20 weeks with hypertension or proteinuria. Refer urgently to neurology and neurosurgery for thunderclap headache, focal signs, papilloedema, seizures, venous thrombosis or haemorrhage. Refer to critical care for eclampsia, status epilepticus, stroke, or reduced consciousness. Refer to anaesthesia for post dural puncture headache.

Admission criteria. Hypertension with symptoms, any red flag, abnormal imaging, persistent severe pain, neurological signs, suspected infection, post dural puncture headache not controlled by oral analgesia, and unsafe home circumstances.

Discharge and follow up. Discharge when the cause is benign, the blood pressure and urine are normal, and the woman can return quickly. Arrange blood pressure check within 24 to 48 hours, a plan for headache, and follow up with the obstetric team. After pre eclampsia, review at 6 weeks, with long term cardiovascular risk review.

Safety netting. Return for severe or worsening headache, visual change, vomiting, drowsiness, confusion, seizure, neck stiffness, fever, weakness, speech difficulty, chest pain, breathlessness, epigastric pain, reduced foetal movements or any new swelling.