BackgroundPostpartum hemorrhage (PPH) is one of the important risk factors leading to maternal mortality and intervention is essential. Oxytocin therapy is widely used clinically, but the effect is unsatisfactory. The efficacy of tranexamic acid (TXA) in hemostasis is notable, whereas its use in preventing PPH warrants exploration.AimsTo evaluate the effect of prophylactic administration of TXA on perioperative blood loss in women undergoing cesarean section by systematic review and meta-analysis of published studies.MethodsBibliographic databases were screened from their inception to December 2022 to retrieve relevant studies. Study outcomes including blood loss during cesarean section, 2-h postpartum blood loss, total blood loss (during cesarean section and 2-h postpartum), and 6-h postpartum, as well as hemoglobin changes were extracted and compared.ResultsA total of 21 studies, nine randomized clinical trials and 12 cohort studies, involving 1896 patients given TXA prophylactically and 1909 patients given placebo or no treatment, were analyzed. Compared with the control group, the preoperative prophylactic intravenous administration of TXA significantly reduced the intraoperative (RCT:P< 0.00001, cohort studies:P< 0.00001), 2-h postpartum (RCT:P= 0.02, cohort studies:P< 0.00001) and total blood loss (RCT:P< 0.00001, cohort studies:P= 0.0002), and reduced the decline in hemoglobin (RCT:P< 0.00001, cohort studies:P= 0.0001), but did not significantly affect blood loss at 6-h postpartum (P= 0.05).ConclusionProphylactic intravenous TXA before cesarean section is helpful in preventing perioperative bleeding in women.Trial registrationhttp://www.crd.york.ac.uk/PROSPERO, identifier: CRD 42022363450.