Acute severe headaches in pregnancy are a ‘red flag’: A review based on case reports and key messages for healthcare practioneers

Headaches are common in pregnancy and the immediate postpartum period. Fortunately >90% of these headaches are primary and benign. Generally, the most common primary headache disorders have a peak incidence at a younger age and affect women disproportionately, especially in the reproductive phase of life. The higher incidence in females may reflect the relationship between headache and sex hormones, particularly oestrogen. In pregnancy, most headaches in the first trimester are primary, while the incidence of secondary headaches increases in the third trimester and the immediate postpartum period. This probably reflects when pre-eclampsia and changes in the coagulation system are the greatest. Despite this, 50 - 70% of headaches in late pregnancy have a primary benign cause. Common causes of headaches in pregnancy and the postpartum period are: migraine (vascular), tension headache (brain tumour), cluster headache (severe pre-eclampsia/eclampsia) and cough (postdural puncture, reversible cerebral vasoconstriction syndrome, idiopathic intracranial hypertension, cerebral venous thrombosis). This article presents two cases of maternal deaths arising from lack of awareness that acute severe headaches in pregnancy may have serious underlying pathology, and that persistent headache should be regarded as a ‘red flag’, as suggested by neurologists.