Meta-analysis: the prophylactic use of tranexamic acid to reduce blood loss during caesarean delivery.

Introduction: The 2022 national guideline on The Prevention and Management of Primary Postpartum Haemorrhage (PPH) recommended consideration of prophylactic tranexamic acid (TXA) for women who are at high PPH risk undergoing caesarean section (CS). This meta-analysis reviews the basis for this recommendation.

Method: PubMed, OVID Medline, EMBASE, Science Citation Index, Scopus, CENTRAL, and ClinicalTrials.gov were searched (from inception to January 2024) for randomised controlled trials comparing prophylactic intravenous TXA with placebo or no treatment in women undergoing CS who received a uterotonic. Our main outcome was PPH > 1L. Secondary outcomes included estimated mean blood loss, blood transfusion, drop in haemoglobin, the need for additional uterotonics, or surgical intervention. Adverse effects of TXA were also assessed.

Results: Sixty-one studies including 25,098 women were identified, and 12,446 received prophylactic TXA. Patients who received prophylactic TXA had significantly reduced likelihood of PPH > 1L (RR, 0.47; 95% CI, 0.38 to 0.59), reduced estimated mean blood loss (MD 185.86 ml, 95% CI 159.14-212.59), and reduced drop in Hb (MD 0.84g/dl, 95% CI 0.72, 0.95). There was a significant reduction in need for additional uterotonics (RR 0.47, 95% CI 0.39-0.57) or surgical intervention (RR 0.54, 95% CI 0.30-0.95).

Conclusion: The reduced risk of PPH > 1L was greatest in patients at higher risk of bleeding. The greatest risk reduction was seen in smaller studies and in studies undertaken in developing economies. Prophylactic TXA administration is effective at reducing the incidence of PPH > 1L at CS. The clinical benefit of universal prophylaxis is questionable; women who are high risk of PPH are more likely to derive benefit.