Severe anaemia doubles antenatal, postnatal mortality risk
Severely anaemic women have twice the risk of dying during or after pregnancy compared to women without anaemia, reveals a major international study.
In a comprehensive review of data from the 2010-2011 WHO Multicountry Survey, 312,281 pregnancies across 29 countries were identified, of which 4,687 involved women with severe anaemia—defined as antenatal or postnatal haemoglobin concentrations of less than 70g/L. A total of 341 maternal deaths occurred, of which 135 were among the severely anaemic women (3 percent of group), while 206 were among the remaining 307,594 women (<1 percent of group). [Lancet Glob Health 2018; doi:10.1016/S2214-109X(18)30078-0]
After factoring in other possible contributors to mortality such as post-partum haemorrhage, general anaesthesia, sepsis, pre-eclampsia, the adjusted odds ratio for maternal death in women with severe anaemia compared with those without severe anaemia was 2.36 (95 percent CI 1.60–3.48). In the propensity score analysis, severe anaemia was also associated with maternal death (adjusted odds ratio 1.86 [95 percent CI 1.39–2.49]).
While previous studies have suggested a strong association between anaemia and mortality, it has been thought to be due to other clinical reasons (eg, blood loss, malarial/dengue infection) and not anaemia directly. The study claims to be the first analysis to take into account factors that influence the development of anaemia in pregnancy (e.g. blood loss or malaria infection) which may have been skewing the results of previous studies.
"Anaemia in pregnancy is one of the most common medical problems pregnant women encounter both in low- and high-income countries,” said lead author Dr Jahnavi Daru, clinical research fellow at the Women’s Health Research Unit, Queen Mary University of London, UK. “We've now shown that if a woman develops severe anaemia at any point in her pregnancy or in the 7 days after delivery, she is at a higher risk of dying, making urgent treatment even more important.”
The WHO survey examined delivery and maternal outcomes in 359 public healthcare facilities in a range of geographical areas, including Latin America, Africa, the Western Pacific, Eastern Mediterranean, and Southeast Asia. The facilities qualified based on number of deliveries per year (1,000+) and capacity for caesarean delivery.
Anaemia (defined generally in women as haemoglobin concentrations of less than 120 to 130 g/L) affects an estimated 32 million pregnant women worldwide and around 50 percent of pregnant women in low- to middle-income countries, due to a higher frequency of nutrient deficiencies, haemoglobinopathy, inherited blood disorders and infectious diseases such as malaria and HIV. [Lancet Glob Health 2013;1: e16–e25]
"Anaemia is a readily treatable condition but the existing approaches so far have not been able to tackle the problem,” said Daru. “Clinicians, policy makers and healthcare professionals should now focus their attention on preventing anaemia, using a multifaceted approach, not just hoping that iron tablets will solve the problem."
However, the authors cautioned that the study was limited by its observational nature, noting that there were difficulties in proving a direct causal relationship between severe anaemia and maternal death due to the multitude of factors involved.