Tranexamic Acid for the Prevention of Obstetrical Hemorrhage After Cesarean

A randomized placebo-controlled trial of 11,000 women to assess whether tranexamic acid as prophylaxis lowers the risk of postpartum hemorrhage in women undergoing a cesarean delivery.

Inclusion Criteria: 1. Scheduled or unscheduled cesarean delivery 2. Singleton or twin gestation Exclusion Criteria: 1. Age less than 18 years 2. Transfusion or planned transfusion of any blood products during the current admission because the primary outcome is already pre-determined and the need for transfusion will be unrelated to perioperative hemorrhage 3. Recent diagnosis or history of venous thromboembolism or arterial thrombosis because TXA is a risk factor for thromboembolism, and its use is contraindicated 4. Known congenital or acquired thrombophilias, including antiphospholipid antibody syndrome, because of the increased risk of thrombosis 5. Seizure disorder (including eclampsia) because TXA is a GABA receptor antagonist, and its use has been associated with postoperative seizures 6. Serum creatinine 1.2 or higher or on dialysis, with renal disease, or a history of renal insufficiency, because TXA is substantially excreted by the kidney, and impaired renal function may increase the risk of toxic reactions. 7. Sickle cell disease, because of substantial use of perioperative transfusion unrelated to hemorrhage. Sickle cell trait is not an exclusion per se. 8. Autoimmune diseases such as lupus, rheumatoid arthritis, Sjogren's disease, and inflammatory bowel disease because of hypercoagulability and the increased risk of thrombosis or thromboembolism 9. Need for therapeutic dose of anticoagulation before delivery, because the risk of thrombosis may be increased with TXA 10. Treatment with clotting factor concentrates, because the risk of thrombosis may be increased with TXA 11. Presence of frank hematuria, because the risk of ureteral obstruction in those with upper urinary tract bleeding may be increased with TXA 12. Patient refusal of blood products because the primary outcome is then pre-determined 13. Receipt of TXA; or planned or expected use of TXA prophylaxis 14. Active cancer, because of risk of thromboembolism 15. Congestive heart failure requiring treatment, because of risk of thrombosis 16. History of retinal disease, because the risk of central retinal artery or vein obstruction may be increased with TXA 17. Acquired defective color vision or subarachnoid hemorrhage, since TXA is contraindicated 18. Hypersensitivity to TXA or any of the ingredients 19. No hemoglobin result available from the last 4 weeks, since it is necessary to measure the post-operative change in hemoglobin 20. Scheduled cesarean delivery and quota for scheduled deliveries already met. Quotas on the number of scheduled and unscheduled deliveries will be placed to ensure approximately equal distribution of scheduled and unscheduled cesarean deliveries. 21. Participation in this trial in a previous pregnancy. Patients who were screened in a previous pregnancy, but not randomized, may be included. 22. Participating in another intervention study where the primary outcome includes postpartum bleeding or thromboembolism, or the study intervention directly affects postpartum bleeding or thromboembolism 23. Receipt of uterotonics, other than oxytocin, or planned or expected use of uterotonic prophylaxis 24. Symptomatic for COVID-19 infection within 14 days prior to delivery