Post Partum Subarachnoid Haemorrhage
Pregnancy, delivery and the postnatal state do not appear to alter a woman's risk of subarachnoid haemorrhage.
In contrast to non-obstetric subarachnoid haemorrhage, those occurring in the peripartum period are more often non-aneurysmal. Radiological signs suggesting a non-aneurysmal cause include a perimesencephalic pattern of bleeding or cortical subarachnoid blood (affecting the sulci of cerebral convexity and sparing the basal cisterns). Of note, cortical subarachnoid haemorrhage can also complicate reversible cerebral vasoconstriction syndrome and cerebral venous sinus thrombosis. Other non-aneurysmal causes of subarachnoid haemorrhage relevant to the postpartum period include intracranial cervicocephalic artery dissection and acute hypertensive crisis, with or without pre-eclampsia. All these can also present as a severe explosive-onset headache, even without haemorrhage.