Tranexamic acid (TXA) reduces menstrual blood loss, but its impact on haemoglobin and anaemia remains uncertain, a systematic review of 17 randomised trials has found. Researchers are calling for high-quality trials involving menstruating women with anaemia to provide evidence.
Tranexamic acid (TXA) can reduce menstrual blood loss, a new PLOS ONE paper finds, but more research is needed to determine its impact on anaemia.
Around half a billion women of reproductive age worldwide have anaemia, with the highest prevalence found in sub-Saharan Africa and South Asia. Despite longstanding international targets, there has been little progress in reducing its prevalence.
Global efforts have largely focused on iron and vitamin supplementation. However, this new review highlights another important part of the problem: the continued loss of iron through menstrual bleeding.
Review finds benefits for menstrual bleeding, but evidence on anaemia is limited
Published by researchers from the London School of Hygiene & Tropical Medicine (LSHTM) and the University of Edinburgh, the systematic review examined whether TXA could help reduce anaemia, and improve the quality of life among women of reproductive age.
TXA is an inexpensive, non-hormonal medicine that reduces bleeding by preventing the premature breakdown of blood clots. It has been used for decades to treat heavy menstrual bleeding, but its potential contribution to preventing or treating anaemia has received relatively little attention.
The researchers searched six international databases and trial registries for randomised trials comparing TXA with a placebo or standard care. They identified 17 trials, 15 of which, involving a total of 1,080 participants, contributed data to at least one of their meta-analyses.
The review found that TXA reduced menstrual blood loss by an average of 47 ml per period in women with heavy bleeding. It also appeared to reduce bleeding in women using an intrauterine device, although the evidence for this group was less certain.
For women with heavy menstrual bleeding, TXA was also associated with improved quality of life. The risk of nausea or vomiting was similar among women receiving TXA and those in the comparison groups. However, none of the trials provided adequate data on changes in haemoglobin concentration, and evidence on anaemia was limited to one small trial and was very uncertain.
Lead author Dr Sima Berendes, Assistant Professor at LSHTM, said:
“We know that TXA can substantially reduce menstrual blood loss, but we were surprised by how little trial evidence there was on haemoglobin and anaemia. Menstrual bleeding is an important source of iron loss, yet it is often missing from the global conversation about anaemia.”
Why menstrual blood loss matters for tackling anaemia
Anaemia occurs when the blood does not contain enough haemoglobin or healthy red blood cells to carry the oxygen the body needs. Its effects can include fatigue, breathlessness, and problems with concentration, affecting women’s health, quality of life, and ability to work.
The consequences can be particularly serious during pregnancy. Anaemia increases risks for both mothers and babies, making it important to identify and address the condition before conception wherever possible.
Current strategies often concentrate on replacing iron through tablets or supplements. While this remains important, supplementation may be insufficient if a woman continues to lose substantial amounts of blood during her periods. Side effects can also make it difficult for some women to take oral iron.
The researchers suggest there may be a “vicious cycle” in which heavy menstrual bleeding contributes to anaemia, while anaemia and iron deficiency may, in turn, worsen bleeding through changes in blood flow and clotting. Reducing menstrual blood loss could potentially help to interrupt this cycle, but trials specifically involving menstruating women with anaemia are needed to test this possibility.
New trials needed to address the evidence gap
Heavy menstrual bleeding is now defined by its effect on a woman’s physical, social, emotional or material quality of life, rather than by blood loss alone. Despite its impact, it frequently goes undiagnosed or untreated. TXA provides a non-hormonal treatment option that preserves fertility, but the review shows that previous trials were not designed to determine whether it improves haemoglobin levels or reduces anaemia.
Another author on the paper, Dr Katharine Ker, an Assistant Professor at LSHTM, said:
“We need to address menstrual blood loss as well as iron deficiency. The team at LSHTM’s Clinical Trials Unit is already recruiting women for the WOMAN-3 Trial, which is investigating whether oral TXA can help break the cycle between heavy menstrual bleeding and anaemia.”
Evidence about rare but serious adverse effects was limited. Only one thromboembolic event, involving a blood clot, was reported across the included trials, and this occurred in a participant in a control group. However, only a small number of trials reported on such events and the trials were too small and follow-up periods too short to draw firm conclusions about rare adverse effects.
Dr Berendes said:
“The global target to halve anaemia has not been achieved, and current anaemia-control strategies alone are unlikely to be enough. We need high-quality randomised trials involving menstruating women with anaemia that measure anaemia, haemoglobin, iron stores and menstrual blood loss.
“We need to look beyond replacing lost iron and examine whether preventing avoidable blood loss can help women build and maintain healthier haemoglobin levels throughout their reproductive lives.”
Publication
Sima Berendes, Katharine Ker, Hilary O. D. Critchley, Raoul Mansukhani and Ian Roberts. Tranexamic acid for anemia in women of reproductive age: A systematic review of randomized trials. PLOS One. DOI: https://doi.org/10.1371/journal.pone.0362488