Moving Beyond Uterotonics for the Treatment of Postpartum Hemorrhage: Lessons From the WOMAN Study

In May of 2017, the long-awaited results of the World Maternal Antifibrinolytic Trial (WOMAN study) of the benefits of tranexamic acid (TXA) for the treatment of postpartum hemorrhage (PPH) were published. The study is one of the largest ever randomized trials in maternal health and certainly the largest related to PPH care. Just over 20 000 women with PPH in 193 hospitals in 21 countries around the world were randomized to receive 1 g of intravenous TXA or matching placebo. The primary outcome was death from PPH, and this was reduced from 1.9% to 1.5% in women who received the TXA, a risk reduction of 0.81 (95% CI 0.65–1.00). The effect was more pronounced in women who received the drug within 3 hours of giving birth, in whom there was a 31% reduction in the rate of death (from 1.7% to 1.2%). The risk of laparotomy for bleeding was reduced even further by nearly 40%. Importantly, TXA appeared to benefit those women with both atonic and traumatic bleeding and was unrelated to the mode of birth. There were no significant differences in any other outcomes. This finding is not surprising, given that multiple therapies (including uterotonics, tamponade, manual removal of placenta, hysterectomy, and blood transfusion) are often used concurrently at the time of a PPH, and they would have been given before the TXA (or placebo) had a chance to work. These other therapies therefore, although classified as “outcome measures,” could just as well be seen to be “baseline data” and are consequently evenly distributed between the study arms. The one exception is “laparotomy for bleeding,” where the procedure tends to be carried out later for ongoing trickling, and for this there was a clear benefit for TXA (unless its administration was delayed for >3 hours). This finding largely fits with TXA's having an important (but not immediate) effect, largely on the “tricklers” who continue to have ongoing blood loss for some hours after birth.