Tranexamic Acid for the Management of Obstetric Hemorrhage
Firstly, the majority of patients were recruited in low- or mid-income countries with high maternal mortality rates. The high death rates from hemorrhage in the TXA and placebo groups (1.5% and 1.9%, respectively) may be due to the lack of massive transfusion protocols and hemostatic-guided resuscitation at study sites. Because death rates from hemorrhage are substantially lower in the United States3 and other developed countries,4 we question the external validity of the trial’s main findings.
Secondly, key data were not reported, including: types of blood components transfused (plasma, platelets), presence and extent of coagulopathy (including hyperfibrinolysis), injury severity, and time to cessation of hemorrhage. Therefore, one cannot determine the contribution of TXA to survival benefit.
Thirdly, from a mechanistic standpoint, it is unclear whether hyperfibrinolysis is a key causative or contributory factor for life-threatening postpartum hemorrhage. The Kruithof et al study5 was cited as recent evidence linking activation of the fibrinolytic pathway to severe hemorrhage.1 However, this study examined lytic parameters in only 10 postpartum women who delivered 30 years ago,5 and relations between these parameters with blood loss were not reported. The lack of between-group differences in transfusion use reported in the WOMAN trial raises questions about how TXA, mechanistically, induces a survival benefit. What is urgently needed are obstetric studies to examine the incidence, timing, and extent of hyperfibrinolysis among women with postpartum hemorrhage and efficacy studies to determine whether current TXA regimens attenuate blood loss and hemorrhage-related morbidity.
Lastly, TXA is not a magic bullet to fix or resolve postpartum hemorrhage etiologies, such as uterine atony. Therefore, TXA is not a true treatment but an adjunct, which should neither replace nor substitute key aspects of postpartum hemorrhage management, including: uterotonic therapy and medical and surgical interventions.