Literature
Clinical Pearls & Morning Reports
Published April 12, 2023
Did tranexamic acid reduce the risk of a primary-outcome event as compared with placebo in the trial by Pacheco et al.?
Pacheco et al. conducted a randomized trial to evaluate whether the administration of tranexamic acid immediately after umbilical-cord clamping lowered the risk of maternal death or blood transfusion as compared with placebo among patients undergoing scheduled or emergency cesarean delivery. Read the NEJM Original Article here.
Clinical Pearls
Q: Is obstetrical hemorrhage the most common cause of pregnancy-related death in the United States?
A: Postpartum hemorrhage is responsible for up to 27.1% of maternal deaths worldwide. In the United States, obstetrical hemorrhage is the second most common cause of pregnancy-related death, second only to cardiovascular disease.
Q: Did tranexamic acid reduce the risk of a primary-outcome event as compared with placebo in the trial by Pacheco et al.?
A: A primary-outcome event (a composite of maternal death or blood transfusion by hospital discharge or 7 days postpartum, whichever came first) occurred in 3.6% of the participants in the tranexamic acid group and in 4.3% of those in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Findings are inconsistent with those of previous observational studies and systematic reviews suggesting that the use of prophylactic tranexamic acid during cesarean delivery reduces the use of blood transfusion. However, 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.
Morning Report Questions
Q: What were some of the secondary outcome results of the trial?
A: 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). Postpartum infectious complications occurred in 3.2% of the participants in the tranexamic acid group and in 2.5% of those in the placebo group (relative risk, 1.28; 95% CI, 1.02 to 1.61). There were no material between-group differences in the incidence of major safety outcomes, including thromboembolic events or new-onset seizure activity.
Q: Describe some of the limitations of this trial.
A: Because tranexamic acid was administered after umbilical-cord clamping, the benefit of earlier administration (before incision), if any, is unknown. The trial excluded patients who were at high risk for thromboembolic phenomena, such as those with a history of thromboembolic events and those with congenital or acquired thrombophilia. The safety of tranexamic acid in this population remains largely unknown and requires further study. Further study is also needed to confirm the finding of a higher incidence of postpartum infections with tranexamic acid, which was unexpected.