Tranexamic acid reduces bleeding risk for caesarean births with placenta praevia

A large Chinese trial has found that prophylactic use of tranexamic acid produced a modest – but statistically significant – reduction in postpartum haemorrhage among women with placenta praevia who underwent caesarean delivery

A drug already used to treat serious bleeding after childbirth has been shown to reduce the risk of postpartum haemorrhage in women with placenta praevia who undergo caesarean section to give birth, according to a large clinical trial from China.

The study team led from the department of obstetrics and gynaecology, Guangzhou Medical University, Guangdong, China, found that tranexamic acid, when given shortly after umbilical cord clamping, led to a significant but modest reduction in severe bleeding after delivery. The researchers found no evidence that the treatment increased serious adverse events, including blood clots, seizures, acute kidney or liver injury or maternal death.

Placenta praevia occurs when the placenta lies low in the uterus and partly or completely covers the cervical opening. The condition increases the risk of severe bleeding before, during and after birth, and caesarean delivery is often required to reduce risk to the mother and baby. Because women with placenta praevia are already at greater risk of substantial blood loss, even a modest reduction in postpartum haemorrhage may have important clinical value.

Tranexamic acid is an antifibrinolytic medicine, which means that it helps to prevent the breakdown of blood clots. It is widely used to reduce heavy bleeding after surgery or trauma and is recommended as a treatment for postpartum haemorrhage, a potentially life-threatening complication of childbirth. However, the authors noted that high-quality evidence for its preventive use in high-risk obstetric patients has remained limited.

To address this evidence gap, the research team assessed whether prophylactic administration of tranexamic acid could reduce postpartum haemorrhage among women with placenta praevia who were scheduled for caesarean delivery. The trial included 1,694 pregnant women treated at 24 maternity units across China between July 2023 and March 2025.

All participants received prophylactic oxytocin, which is standard treatment to help the uterus contract and reduce blood loss after delivery. The women were then randomly assigned to receive either intravenous tranexamic acid or placebo. In total, 845 women received tranexamic acid and 849 received placebo. The treatment was given across 10 minutes and started within five minutes of umbilical cord clamping.

The main outcome was postpartum haemorrhage, defined as blood loss of at least 1,000 millilitres or the need for red blood cell transfusion within two days after delivery. The investigators also recorded serious adverse events, including thrombotic events, seizures, acute kidney or liver injury and maternal death.

The trial showed that prophylactic tranexamic acid reduced the rate of postpartum haemorrhage from 35.1 per cent in the placebo group to 29.7 per cent in the tranexamic acid group. This represented a relative reduction of 15 per cent. In practical terms, the researchers calculated for every 19 women receiving prophylactic tranexamic acid it would prevent one case of postpartum haemorrhage.

Rates of serious adverse events were similar between the treatment and placebo groups, which suggested that the intervention did not introduce a detectable safety penalty in this trial population. The authors nevertheless acknowledged that the findings applied specifically to women with placenta praevia who received prophylactic oxytocin and underwent caesarean delivery. They cautioned that the results may not translate to use in other obstetric populations.

The team also noted several limitations but said the study had been well designed and that the results remained consistent after further analyses. This supported the robustness of the findings.

“In a high risk population – specifically, women with placenta praevia undergoing caesarean delivery – prophylactic tranexamic acid leads to a statistically significant [if] modest reduction in the incidence of postpartum haemorrhage,” the researchers concluded.

“Future studies in diverse international settings are warranted to validate these results and to identify specific patient subgroups [that are] most likely to benefit from prophylactic use of tranexamic acid,” they added.

In peer review from researchers in the UK, it was noted that even the modest reduction in bleeding they found should not be dismissed, particularly among women at high risk of harm from haemorrhage. They argued that, in such patients, even modest relative risk reductions can translate into worthwhile clinical benefits.

Attention should now move from whether tranexamic acid reduces bleeding to how it should be used to maximise benefit. They noted that in non-obstetric surgery tranexamic acid is often given before incision, whereas in caesarean section trials it has usually been delayed until after cord clamping to avoid placental transfer to the baby.

They recommended that future studies should evaluate pre-incision administration for caesarean section, while carefully monitoring maternal and neonatal outcomes. This approach, they suggested, could help to clarify whether earlier treatment provides greater protection against blood loss without unacceptable risk.

For further reading please visit: 10.1136/bmj-2026-089636