Tranexamic Acid by the Intramuscular or Intravenous Route for the Prevention of Postpartum Haemorrhage in Women At Increased Risk: a Randomised, Double-blind, Placebo-controlled Trial

Postpartum haemorrhage (PPH) causes about 70,000 maternal deaths every year. Tranexamic acid (TXA) is a lifesaving treatment for women with PPH. The WOMAN trial recruited over 20,000 women with PPH and found that intravenous (IV) TXA given soon after PPH onset, reduces bleeding deaths by about a third. Early TXA also reduces blood loss in surgery and death due to bleeding after traumatic injury. The World Health Organization recommends that all women with PPH should receive TXA as a first line treatment.

TXA is more effective when given soon after the bleeding starts. Every fifteen minute delay reduces the survival benefit by about 10%. This suggests that giving TXA around the time of childbirth might prevent PPH. Although several clinical trials have examined the effectiveness of TXA for the prevention of PPH, the results are inconclusive. Trials of tranexamic acid for PPH prevention give the trial treatment after cord clamping, which may be too late to prevent bad bleeding in some women, as bleeding tends to happen soon after childbirth. Because PPH only affects a small proportion of births, the healthcare community need good evidence on the balance of benefits and harms in this population before using TXA to prevent PPH.

The I'M WOMAN trial will evaluate the effects of TXA for PPH prevention in women with one or more risk factors for PPH having a vaginal or caesarean birth. The trial will also evaluate the effect of the route of TXA administration. TXA is usually given by slow IV injection. However, recent research shows that TXA is well tolerated and rapidly absorbed after IM injection, achieving therapeutic blood levels within minutes of injection. There may be fewer side effects with IM TXA because peak blood concentrations are lower than with the IV route, as well as practical advantages.