Headache during pregnancy

Background

• Must r/o preeclampsia/eclampsia in > 20 wks gestation
• Most pregnant women with primary HAs have dx before pregnancy
• 10% pregnant women will have new presentation during gestation, of which:
  • 1/3 have migraine
  • 1/3 have PET/eclampsia HA

DDx

• Consider usual differential for HAs
• May need pre-eclampsia/eclampsia r/o
• New onset of severe HA in no hx of migraines, keep high suspicion of:
  • ICH
  • Temporal arteritis
  • Vertebral and carotid artery dissection
  • Cerebral venous thrombosis
  • Cavernous sinus thrombosis
  • Meningitis
  • Reversible posterior leukoencephalopathy
  • Pituitary apoplexy

Workup

• Clinical suspicion guides labs and imaging
• LP if increased ICP or infection suspected
• MRI/MRA/MRV preferred to CT head, though radiation scatter minimal
• Avoid gadolinium; Iodine contrast may be safe

Management

• Initial - acetaminophen 1000 mg PO, and may add:
  • Metoclopramide 10 mg IM/IV or PO
  • Codeine 30 mg PO
• Other options
  • Sumatriptan 100 mg PO or 4-6 mg SQ
  • Diphenhydramine 25 - 50 mg PO
  • Promethazine 12.5 - 25 mg PO
  • Ondansetron 4 - 8 mg IV for severe n/v
    • Ensure no hypokalemia, hypomagnesaemia, hypocalcemia for prolonged QT
    • Consider recent conflicting studies on risk of birth defects
• Refractory migraine option 1:
  • IV hydration
  • Pre-Tx diphenhydramine 25 mg for EPS
  • Antiemetic
  • IV opioid
• Refractory migraine option 2:
  • Triptan
  • Droperidol 2.5 mg IV q30 min up to 3 doses
• Consider peripheral nerve blocks
• Consider steroids in intractable migraines
  • Prednisone 20 mg PO QID x2 days or methylprednisolone 4 mg PO, 21 tablets over 6 days
  • Avoid dexamethasone and betamethasone
  • Avoid steroids in 1st trimester
• No benefit of IV magnesium in meta-analysis

Pregnancy Categories of Common Medications

• Class B - acetaminophen, caffeine, metoclopramide, promethazine
• Class C - prochlorperazine (not enough human data but studies suggest safety), prednisolone, droperidol, ketorolac, 5-HT1 agonists (triptans), gabapentin, topiramate, CCBs, TCAs
• Class D - valproate
• Class D in 3rd trimester - aspirin, ibuprofen, naproxen
• Class D at term or prolonged use - codeine, morphine, BBs
• Class X - dihydroergotamine, ergotamine
• Breastfeeding compatible - aspirin, caffeine, ibuprofen, naproxen, codeine, morphine, prednisolone, triptans (likely compatible), BBs
• Breastfeeding contraindicated - dihydroergotamine, ergotamine