Outcomes of subsequent pregnancy following obstetric transfusion in a first birth

Increasing rates of postpartum haemorrhage and obstetric transfusion mean that more women are entering subsequent pregnancies with a history of blood transfusion. This study investigates subsequent pregnancy outcomes of women with a prior obstetric red cell transfusion, compared to women without a transfusion.

All women with a first pregnancy resulting in a liveborn singleton infant of at least 20 weeks gestation delivering in hospitals in New South Wales, Australia, between 2003 and 2012 were included in the study, with followup for second births until June 2015. Linked hospital and births data were used to identify women with a transfusion and/or postpartum haemorrhage in their first birth, time to second pregnancy and adverse birth outcomes (including transfusion, postpartum haemorrhage and severe morbidity) in their subsequent birth.

There were 358,384 singleton births to primiparous women, with 1.4% receiving an obstetric blood transfusion. Sixty-three percent of women had at least one subsequent birth. The relative risk (RR) of requiring a transfusion in a second birth was 4.9 (95% CI 4.1,6.1) for women with a previous transfusion compared with women without. The risk (RR) of severe morbidity in a second birth was 4.1 times higher (95% CI 2.2,7.4) for those receiving a transfusion without haemorrhage in their first birth compared with women with neither haemorrhage nor transfusion.

It is important to consider a woman's history of transfusion and/or haemorrhage as part of her obstetric history to ensure management in a manner that minimises risk in subsequent pregnancies.