Outcomes associated with transfusion in low-risk women with obstetric haemorrhage

Background and Objectives: Obstetric haemorrhage is associated with increased blood transfusion, morbidity and health service usage in women. While the use of transfusion in actively bleeding patients is supported, there is little evidence for the use of blood as treatment in the nonbleeding patient following obstetric haemorrhage. Transfusion may expose women to increased morbidity. This study aims to compare outcomes between low-risk women receiving no or 1–2 units of blood in the context of obstetric haemorrhage. Materials and Methods: The study population included women giving birth in hospital in New South Wales, Australia, between July 2006 and December 2010, with a diagnosis of obstetric haemorrhage. Women with medical or obstetric conditions making them high risk were excluded, as were women receiving more than 2 units of blood. Data were obtained from linked hospital, birth and blood bank databases. Propensity score matching was used to compare outcomes between transfused and nontransfused women in order to estimate the impact of the transfusion itself on outcomes. Results: There were 14989 women with obstetric haemorrhage, of whom, 1702 received a transfusion, including 1069 receiving a transfusion of 1–2 units. Women receiving transfusion were more likely to experience severe maternal morbidity (relative risk 7·0, 95% Confidence interval (2·8, 17·8)), be admitted to intensive care (RR 2·1 95% CI(1·2, 3·8)), and have a length of stay >5 days (RR 2·0, 95% CI (1·6, 2·5)). Conclusions: Small volume transfusion in the context of obstetric haemorrhage among low-risk women is associated with poorer maternal outcomes and increased healthcare utilisation.