Tranexamic acid for the prevention of postpartum haemorrhage: the TAPPH-1 pilot randomized trial and lessons learned for trials in Canadian obstetrics

Postpartum haemorrhage (PPH) is a leading cause of maternal morbidity and mortality. While tranexamic acid (TXA) reduces bleeding and transfusion requirements in established PPH, we sought to determine the feasibility of conducting a fully powered trial assessing the effect of prophylactic tranexamic acid, prior to PPH onset, in a Canadian Obstetric setting. With institutional and Health Canada approval, consenting, eligible parturients (singleton, > 32 weeks gestation, vaginal or caesarian delivery) were randomly assigned to receive TXA (1 g intravenously) or placebo (0.9% saline) prior to delivery. Participants, investigators, data collectors/adjudicators, and analysis was blinded. The primary outcome was administration of study intervention to > 85% of randomized individuals. Secondary outcomes included recruitment rate (feasibility) and safety outcomes. Over 8 months, 611 were approached, 35 consented, and 27 randomized (14 TXA, 13 placebo). 89% of randomized participants received the assigned intervention. Recruitment fell below feasibility (23% target). No serious adverse outcomes occurred. Our pilot trial in a Canadian Obstetric setting was unable to demonstrate feasibility to conduct a large, multicentre trial to examine prophylactic use of tranexamic for PPH secondary to the complex regulatory requirements associated with a trial for an off-label, but commonly utilized intervention. These challenges should inform stakeholders on the resources and challenges of conducting future trials using off-label interventions. Trial registration: www.clinicaltrials.gov, NCT03069859 (03/03/2017).