• Worm infestation due to unsafe water and lack of hygiene is a major cause of blood deficiency in Pakistan, says lead investigator
• Research finds women with the condition can develop shock, organ failure after only moderate bleeding
KARACHI: Presenting the missing evidence that could have a huge impact on the lives of mothers and their babies, a recently concluded multi-country study has found that anaemia, rather than postpartum haemorrhage (PPH), is the leading cause of maternal deaths worldwide.
The study calls for an urgent review of the efforts being made to address the PPH.
The findings of the WOMAN-2 study are released by the London School of Hygiene & Tropical Medicine, which coordinated the trials under an international alliance of doctors, midwives, research scientists and patients, in a report titled The Missing Evidence: Anamia, Postpartum Bleeding and Maternal Death.
The clinical investigation spread over six years involved 15,068 women with moderate and severe anaemia giving birth in hospitals in Pakistan, Tanzania, Nigeria and Zambia. Of them, 1,1025 women — the highest number — were from Pakistan.
It examined the effects of anaemia on women giving birth and evaluated the effects of Tranexamic Acid (TXA) on the risk of the PPH — heavy, dangerous bleeding after childbirth — and other important outcomes in these high-risk vulnerable women.
The study found that anaemia greatly increases the risk of a clinical diagnosis of the PPH; the clear stepwise increase in the PPH with worsening anaemia strongly suggests a causal relationship.
Although women with severe anaemia had an increased risk of clinical PPH, the data suggest that their inability to tolerate normal bleeding could explain much of the increased risk of PPH and death.
“First, based on the prevalence of anaemia and the strength of the association between anaemia and severe PPH, we estimate that anaemia could be responsible for half of severe PPH cases in sub-Saharan Africa and South Asia.
“Anaemia is also a strong risk factor for maternal death and so anaemia may be responsible for most maternal deaths. In other words, our data suggest that anaemia rather than PPH is the leading cause of maternal death worldwide,” the report says.
Women with moderate and severe anaemia, it says, can develop shock and organ failure after only moderate bleeding, “therefore even the updated WHO definition of PPH fails to identify many women at high risk of death or near miss”.
“As part of our research, we set out to determine how accurate a diagnosis of PPH was in women with anaemia. The data showed that measuring blood loss alone was not accurate in identifying women at high risk of PPH death.”
PPH rarely fatal in high-income countries
Many policy reports on maternal mortality claim that the PPH is the “leading cause of maternal death worldwide”.
However, researchers say, this statement overlooks one key epidemiological fact: the PPH affects women everywhere, but almost all of the deaths are in low- and middle-income countries, mostly sub-Saharan Africa and South Asia. The PPH is rarely fatal in high-income countries.
Until recently, the WHO defined the PPH as a blood loss of 500ml or more within 24 hours of childbirth. In high-income countries, women can lose this much blood without serious consequences. Indeed, in many high-income countries the definition of the PPH has been revised upwards to over 1,000ml.
But, in sub-Saharan Africa and South Asia, women can become critically ill after losing a few hundred millilitres of blood.
Half of all women of reproductive age in sub-Saharan Africa and South Asia have anaemia but surprisingly, there have been no large scientific studies of effects of anaemia on women giving birth.
Anaemia widespread in Pakistan
Speaking to Dawn, Dr Rizwana Choudhary, lead investigator of the study from Pakistan and professor at Shifa Tameer-e-Millat University, Islamabad, says that the study is an eye-opener.
“The results showed that maternal mortality and morbidity is directly proportional to the haemoglobin (level). Low levels of haemoglobin increase the risk for PPH, antepartum haemorrhage (vaginal bleeding during the second half of pregnancy), neonatal mortality and stillbirths,” she said, emphasising that “anaemia must be addressed, if we want to save our mothers”.
According to her, the majority of pregnant women in Pakistan are anaemic. A 2024 local study suggests its prevalence up to 70 per cent.
The common causes of anaemia in women, she says, are worm infestation due to consumption of unsafe water and lack of hygiene, poor nutrition, heavy menstrual bleeding, especially in the younger age group, and repeated pregnancies. Haemorrhoids (piles) and thalassemia can also cause anaemia. said, emphasising that “anaemia must be addressed, if we want to save our mothers”.
According to her, the majority of pregnant women in Pakistan are anaemic. A 2024 local study suggests its prevalence up to 70 per cent.
The common causes of anaemia in women, she says, are worm infestation due to consumption of unsafe water and lack of hygiene, poor nutrition, heavy menstrual bleeding, especially in the younger age group, and repeated pregnancies. Haemorrhoids (piles) and thalassemia can also cause anaemia.
“This is really sad that women do not seek help for irregular, heavy periods before marriage or during pregnancy,” she said, adding that anaemia prevention required a life-course approach.
Increased risk for stillbirths
The study found moderate and severe anaemia have a major impact on the physical and mental wellbeing of women giving birth. With worsening anaemia, women report more: shortness of breath at rest and after exercise, dizziness, fatigue and difficulty in concentrating.
The research also showed that anaemia increases the likelihood of premature births and stillbirths. An astonishing 17 per cent of women with severe anaemia had a stillbirth. The figure for women with moderate anaemia was 5 per cent which is still much higher than for women without anaemia.
Most women giving birth with moderate and severe anaemia leave hospital with an even lower haemoglobin concentration than before the birth. On average, the haemoglobin concentration fell by 9 g/L in women with moderate anaemia and by 17 g/L in women with severe anaemia.
It also found that episiotomy, a common obstetric practice, may contribute to the worsening of maternal anaemia.
Although the WHO does not recommend routine episiotomy because the risks outweigh any potential benefits, 29 per cent of the women who took part in the study had an episiotomy.
The chance of first-time mothers having the procedure was 81pc in Pakistan, 63pc in Nigeria, 29pc in Zambia and 15pc in Tanzania.
Furthermore, of all the first-time mothers who had an episiotomy, 81pc had no pain relief.
The trial analyses showed that there would be an overall reduction in deaths if all women giving birth in sub-Saharan Africa and South Asia received TXA at the time of delivery.
Published in Dawn, June 17th, 2026
