In 11,000 patients undergoing cesarean delivery, prophylactic use of tranexamic acid did not significantly reduce the risk of a composite outcome of maternal death or blood transfusion compared with placebo, researchers report. The findings of this pragmatically designed trial differ from previous observational studies and systematic reviews, the authors note, many of which suggested that prophylactic tranexamic acid during cesarean delivery reduced the use of blood transfusion. “Many of these trials were small, single-center studies that were prone to biases, and none were adequately powered to evaluate the use of blood transfusion,” the group writes.
The study was conducted at 31 U.S. hospitals, where patients undergoing cesarean delivery received either tranexamic acid or placebo after umbilical-cord clamping. Based on a primary outcome of a composite of maternal death or blood transfusion by hospital discharge or 7 days postpartum, whichever came first, the study showed: “Scheduled cesarean delivery accounted for 50.1% and 49.2% of the deliveries in the [transexamic acid and placebo] groups. A primary-outcome event occurred in 201 of 5,525 participants (3.6%) in the tranexamic acid group and in 233 of 5,470 (4.3%) in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Estimated intraoperative blood loss of more than 1 liter occurred in 7.3% of the participants in the tranexamic acid group and in 8.0% of those in the placebo group (relative risk, 0.91; 95% CI, 0.79 to 1.05). Interventions for bleeding complications occurred in 16.1% of the participants in the tranexamic acid group and in 18.0% of those in the placebo group (relative risk, 0.90; 95% CI, 0.82 to 0.97); the change in the hemoglobin level was −1.8 g per deciliter and −1.9 g per deciliter, respectively (mean difference, −0.1 g per deciliter; 95% CI, −0.2 to −0.1); and postpartum infectious complications occurred in 3.2% and 2.5% of the participants, respectively (relative risk, 1.28; 95% CI, 1.02 to 1.61). The frequencies of thromboembolic events and other adverse events were similar in the two groups.”