Tranexamic acid prevents blood loss after cesarean delivery
Treatment with tranexamic acid significantly reduced the incidence of calculated estimated postpartum blood loss of more than 1000 mL or red‐cell transfusions within 2 days of cesarean delivery, according to a randomized controlled trial.
However, tranexamic acid did not reduce the incidence of hemorrhage-related secondary clinical outcomes — a surprising finding, researchers said.
“In fact, all meta-analyses of summary data of small single‐center, randomized controlled trials have shown that tranexamic acid administration at cesarean delivery resulted in significantly less mean gravimetrically estimated blood loss as well as in less frequent blood loss exceeding 500 mL and 1000 mL, less frequent use of additional uterotonic agents, and fewer transfusions than placebo or no treatment,” study author Loïc Sentilhes, MD, PhD, of the department of obstetrics and gynecology at Bordeaux University Hospital in France, told Healio Primary Care.
“Nevertheless, meta-analyses of small trials are prone to biases, especially publication bias,” Sentilhes continued. “Positive findings in small trials are often not substantiated by subsequent large, randomized trials.”
The multicenter, double-blind, randomized controlled trial included 4,153 women who were at least 34 weeks pregnant and undergoing cesarean delivery. All women in the study received prophylactic uterotonic agents intravenously. Approximately half (n = 2,085) were randomly assigned to receive additional treatment with 1 g of tranexamic acid, and the rest received a placebo. Women with hemoglobin levels of less than 9 g per dL were not included “to reduce the likelihood of postpartum transfusion in the absence of clinically significant blood loss,” according to the researchers.
Sentilhes and colleagues reported in The New England Journal of Medicine that 26.7% of the women in the tranexamic acid cohort and in 31.6% of those who received a placebo experienced postpartum hemorrhage (adjusted RR = 0.84; 95% CI, 0.75-0.94) — defined as an estimated blood loss exceeding 1000 mL or receipt of a red-cell transfusion within 2 days of delivery. The mean between-group difference was approximately 100 mL, and likely stemmed from “a significantly smaller decrease in hematocrit from before surgery to after surgery in the tranexamic acid group than in the placebo group,” according to the researchers.
The findings are the first to show “with a high level of evidence that tranexamic acid prevents blood loss after a cesarean delivery,” Sentilhes said.
However, the researchers questioned the clinical relevance of their finding, since there were no significant between-group differences in the secondary clinical outcomes — mean number of gravimetrically estimated blood loss or in the percentage of women with provider-assessed clinically significant postpartum hemorrhage, use of additional uterotonic agents or postpartum blood transfusion.