Tranexamic acid for preventing postpartum haemorrhage after caesarean section

Abstract

Rationale Postpartum haemorrhage (PPH) is common and potentially life‐threatening. The antifibrinolytic drug tranexamic acid (TXA) is recommended for treating PPH; it reduces the risk of death from haemorrhage by one‐third when given soon after bleeding onset, but not overall risk of death. Interest in whether TXA may be effective in preventing PPH is growing. Evidence indicates that TXA given more than three hours after injury to bleeding trauma patients increases mortality. Potential harm becomes critical in prophylactic use of TXA. Reliable evidence of the effect and safety profile of TXA is required before widespread prophylactic use can be considered. Objectives To assess the effects of TXA for preventing PPH compared to placebo or no treatment (with or without uterotonic co‐treatment) in women during caesarean birth. Search methods We searched CENTRAL, MEDLINE, Embase, and WHO ICTRP to 20 February 2024 and searched reference lists of retrieved studies. Eligibility criteria We included randomised controlled trials (RCTs) evaluating the use of TXA alone or plus uterotonics during caesarean birth for preventing PPH. Trials needed to be prospectively registered (i.e. before starting recruitment). We applied a trustworthiness checklist. Outcomes The critical outcome was blood loss ≥ 1000 mL, measured using estimated or calculated methods. Important outcomes included maternal death, severe morbidity, blood transfusion, the use of additional surgical interventions to control PPH, thromboembolic events, use of additional uterotonics, hysterectomy, maternal satisfaction, and breastfeeding at discharge. Risk of bias We assessed risk of bias in the included studies using Cochrane's RoB 1 tool. Synthesis methods Two review authors independently selected trials, extracted data, and assessed risk of bias and trial trustworthiness. We pooled data using random‐effects meta‐analysis. We assessed the certainty of the evidence using GRADE. Included studies We included six RCTs with 15,981 participants. All 12 trials in the previous version of this review were not included after review of trial registrations and trustworthiness checklists. Most included studies involved women at low risk of PPH and were conducted in high‐resource settings. Synthesis of results Prophylactic TXA in addition to standard care compared to placebo in addition to standard care or standard care alone TXA results in little to no difference in estimated blood loss ≥ 1000 mL (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.79 to 1.11; 4 RCTs; n = 13,042; high certainty evidence), resulting in 8 fewer per 1000 women having estimated blood loss ≥ 1000 mL (from 30 fewer to 16 more). TXA likely results in a slight reduction in calculated blood loss ≥ 1000 mL (RR 0...