A new study by researchers at Oxford Population Health has found that anaemia, or low levels of haemoglobin or red blood cells, increases the risk of postpartum haemorrhage (PPH). The risk is further increased for severely anaemic pregnant women who receive interventions to start or speed up the progress of their labour without a valid clinical reason. The study is published in International Journal of Gynecology & Obstetrics.
During childbirth, it may be necessary to medically start labour (induction), or speed up labour (augmentation) if the process is taking a long time, as prolonged labour can be dangerous for both mother and baby. While these practices are generally safe, there is currently little evidence about whether the interventions could increase the risk of postpartum haemorrhage in women who have anaemia. Postpartum haemorrhage (PPH) is severe heavy bleeding after childbirth. It is a leading cause of maternal death, and is particularly common among women in low-and-middle income countries.
Researchers collected data prospectively from 9,420 pregnant women from 13 hospitals across India which are part of the Maternal and perinatal Health Research collaboration, India (MaatHRI). Blood tests were performed when the women were more than 28 weeks’ pregnant and the women were categorised into groups of no/mild anaemia, moderate anaemia, or severe anaemia. The researchers also collected data on blood loss during childbirth and whether women had PPH after giving birth.
It was found that anaemia in late pregnancy increased the risk of PPH and the risk is substantially higher in women with severe anaemia who are induced or augmented without a clinical indication. These findings contribute to our knowledge of the safety of inducing or augmenting labour in women with anaemia, and provide key recommendations for healthcare providers.
Key recommendations:
- National and international clinical guidelines for labour induction/augmentation should consider advising against elective induction/augmentation (ie without a clinical indication) in pregnant women with severe anaemia, in addition to reiterating the importance of prevention and treatment of anaemia in pregnancy;
- The role of prevention and minimising unnecessary interventions in labour is important considering that a recent trial showed that PPH in women with moderate-severe anaemia cannot be prevented by prophylactic tranexamic acid, a drug used to try to prevent severe bleeding after childbirth;
- If a need for labour induction/augmentation is ascertained for women with severe anaemia despite a lack of clear clinical indication, the third stage of labour should be actively managed and the clinical team should be prepared to identify bleeding early and manage it appropriately.
Associate Professor Manisha Nair, Senior Research Fellow at Oxford Population Health, said ‘Our findings contribute to new evidence about the safety of labour induction/augmentation, considering the growing evidence of increased risk of PPH among women with anaemia. Considering the global widespread practice of labour induction/augmentation as well as high and growing worldwide rates of anaemia in pregnancy, it is important to avoid unnecessary interventions during labour and childbirth to reduce the risk of PPH in pregnant women with severe anaemia.’
The Maternal and perinatal Health Research collaboration, India (MaatHRI), led by Associate Professor Manisha Nair, was established in September 2018. It is a large and diverse platform for researchers to conduct large-scale epidemiological research through an Oxford-India collaboration to improve the clinical management and outcomes of pregnant women and babies.