The irrevocable connection between anaemia and maternal health Premium

A study in the Lancet conducted on anaemic pregnant women of low-and middle-income countries has found that there is a strong link between anaemia and postpartum haemorrhage, with the risk of death or near miss very high

The WOMAN-2 trial collaborators, ‘Maternal anaemia and the risk of postpartum haemorrhage: a cohort analysis of data from the WOMAN-2 trial’, The Lancet, June 27, 2023, doi.org/10.1016/S2214-109X(23)00245-0

Of late anaemia has been in the news in India, what with the government proposing to remove a question on it from the National Family Health Survey (NFHS) and instead do a more elaborate test to determine haemoglobin levels in the blood as part of the Diet and Biomarker (DAB) survey. A paper recommending that normative values for haemoglobin must be lowered in India, based on a small study, has also come in for criticism. The WhatsApp groups of two professional sectors, where repartees have been flying hard and fast are those belonging to nutritionists and obstetricians and gynaecologists. The latter groups who have actually seen the impact of anaemia especially on maternal and infant health have been articulating their views on keeping the standards for anaemia, and to not amend them based on a statistically insignificant study. Policy makers in India must allow the results of a multi-country study published recently in The Lancet to inform their rules on measuring anaemia, handling it and making sure the interventions are sensible and far reaching.

Anaemia has a very strong link with postpartum haemorrhage (excessive vaginal bleeding after delivery), and the risk of death or near miss is very high.

As per the study, by the WOMAN (World Maternal Antifibrinolytic )-2 trial collaborators, worldwide, more than half a billion women of reproductive age are anaemic. Each year, about 70,000 women who give birth die from postpartum haemorrhage, almost all of them in low-and middle-income countries. While a known risk of anaemia or low haemoglobin levels is postpartum death, researchers decided to examine in detail the association between anaemia and the risk of postpartum haemorrhage.

This trial enrolled over 10,000 women with moderate or severe anaemia giving birth vaginally in hospitals in Pakistan, Nigeria, Tanzania, and Zambia, countries where anaemia in pregnancy was common and established by other trials. They examined the continuous association between prebirth haemoglobin and the risk of postpartum haemorrhage in a large cohort of women from low-and middle-income countries. The advantage of examining anaemia as a continuous variable, the authors argued, is that demonstration of a monotonic biological gradient is more suggestive of a causal relationship. The outcome was defined as an occurrence of postpartum haemorrhage, defined in three ways: “clinical postpartum haemorrhage (estimated blood loss ≥500 mL or any blood loss sufficient to compromise haemodynamic stability); WHO-defined postpartum haemorrhage (estimated blood loss of at least 500 mL); and calculated postpartum haemorrhage (blood loss of ≥1,000 mL).

The mean age of the women from Pakistan, Nigeria, Tanzania and Zambia was just over 27 years. There was clear evidence from the study that lower haemoglobin values had a direct relationship with volume blood loss, and clinical postpartum haemorrhage. “We found that with decreasing maternal haemoglobin concentration, the risk of postpartum haemorrhage increases monotonically,” the authors recorded.

Anaemia reportedly reduces the oxygen-carrying capacity of blood, and therefore, women with anaemia cannot tolerate the same volume of bleeding as healthy women, and become shocked after a smaller volume blood loss, the authors reasoned. Further they added, “Given the lack of an established definition of postpartum haemorrhage in women with anaemia, before conducting this study, we examined different definitions of postpartum haemorrhage in terms of their specificity for substantial bleeding, and their association with fatigue, physical endurance, and breathlessness.” They eventually found that a clinical diagnosis of postpartum haemorrhage was highly specific for clinical signs of shock and irrevocably associated with worse maternal function.