RESUMO
BACKGROUND: The American College of Obstetricians and Gynecologists states that the current data are insufficient to recommend tranexamic acid prophylaxis for postpartum hemorrhage. OBJECTIVE: This study's objective was to evaluate if prophylactic tranexamic acid treatment reduces the calculated blood loss when compared with a placebo in women undergoing an elective repeat cesarean delivery. STUDY DESIGN: This was a double-blind, randomized, placebo-controlled trial in which the calculated blood loss was determined after administration of prophylactic doses of 1 g of tranexamic acid before skin incision and after placental delivery and standard uterotonics in women with singleton pregnancies at ≥37 weeks' gestation presenting for their second or third cesarean delivery under neuraxial anesthesia. The primary outcome was calculated blood loss at 24 hours. The calculation was based on each participant's height, weight, and the difference in hematocrit before the start of surgery and 24 hours after delivery. Prespecified secondary outcomes were quantification of maternal coagulation activity during the perioperative course. A sample size of 50 women per group was planned (N=100) based on a meta-analysis of mean reduction in blood loss after tranexamic acid. RESULTS: A total of 723 women were screened, and 110 women were randomized as follows: 55 to the tranexamic acid group and 55 to the placebo group. The primary outcome of mean calculated blood loss was 2274±469 mL for the tranexamic acid group and 2407±388 mL for the placebo group (P>.05). For the secondary outcomes, D-dimer levels were lower in the tranexamic acid group than in the placebo group 24 hours after delivery (2.1±1.2 µg/mL vs 4.3±2.4 µg/mL; P<.001). CONCLUSION: Prophylactic tranexamic acid treatment did not decrease the mean calculated blood loss. Significantly less participants had a calculated blood loss >2000 mL in the tranexamic acid group than in the placebo group and had lower levels of D-dimer at 24 hours.