Effects of tranexamic acid preconditioning on the incidence of postpartum haemorrhage in vaginal deliveries with identified risk factors in China: a prospective, randomized, open-label, blinded endpoint trial

Objective This study aimed to evaluate the effects of tranexamic acid (TXA) in preventing postpartum haemorrhage (PPH) among women with identified risk factors for PPH undergoing vaginal delivery in China.Methods This prospective, randomized, open-label, blinded endpoint (PROBE) trial enrolled 2258 women with one or more risk factors for PPH who underwent vaginal delivery. Participants were randomly assigned in a 1:1 ratio to receive an intravascular infusion of 1 g TXA or a placebo immediately after the delivery of the infant. The primary outcome assessed was the incidence of PPH, defined as blood loss ≥500 mL within 24 h after delivery, while severe PPH was considered as a secondary outcome and defined by total blood loss ≥1000 mL within 24 h.Results 2245 individuals (99.4%) could be followed up to their primary outcome. PPH occurred in 186 of 1128 women in the TXA group and in 215 of 1117 women in the placebo group (16.5% vs. 19.2%; RR, 0.86; 95% CI, 0.72 to 1.02; p = 0.088). Regarding secondary outcomes related to efficacy, women in the TXA group had a significant lower rate of severe PPH than those in the placebo group (2.7% vs. 5.6%; RR, 0.49; 95% CI, 0.32 to 0.74; p = 0.001; adjusted p = 0.002). Similarly, there was a significant reduction in the use of additional uterotonic agents (7.8% vs. 15.6%; RR, 0.50; 95% CI, 0.39 to 0.63; p