This document outlines the steps to take in response to a maternal collapse or impending arrest. It includes actions to take, roles to assign, medications and treatments to administer, and reversible causes to consider. Key steps are to call an arrest team, open the airway, start CPR and defibrillation if needed, administer adrenaline, and perform a caesarean section if no return of spontaneous circulation within 4 minutes of the arrest. The checklist is intended to guide responders through the critical actions and ensure nothing is missed during the emergency response.