Prophylactic tranexamic acid in parturients at low risk for post-partum haemorrhage: systematic review and meta-analysis.

Tranexamic acid is effective in reducing blood loss during various types of surgery and after trauma. No compelling evidence has yet been presented for post-partum haemorrhage. A systematic literature search of relevant databases was performed to identify trials that assessed blood loss and transfusion incidence after tranexamic acid administration for post-partum haemorrhage. The random effects model was used for meta-analysis. Risk ratios (RRs) and weighted mean differences (WMDs) were calculated with 95% confidence intervals (CIs). Seven trials with a low risk of bias comparing tranexamic acid vs. placebo with a total of 1760 parturients were included in our systematic review and meta-analysis. Blood loss was significantly lower after tranexamic acid use (WMD -140.29 ml, 95% CI -189.64 to -90.93 ml; P<0.00001). Tranexamic acid reduced the risk for blood transfusions (RR 0.34, 95% CI 0.20-0.60, P=0.0001). The incidence of transfusions in the placebo group varied between 1.4% and 33%. When omitting the two trials with the highest incidence of transfusions, the RR was no longer significant. Additional uterotonics were necessary in the placebo groups; gastrointestinal adverse events were more common after tranexamic acid use. Only four cases of thrombosis were found, two each in the tranexamic acid and control groups. Tranexamic acid effectively reduced post-partum blood loss; the effect on the incidence of blood transfusions requires further studies. Only few trials observed adverse events including thromboembolic complications and seizures.