Haematological features, transfusion management and outcomes of massive obstetric haemorrhage: findings from the Australian and New Zealand Massive Transfusion Registry

Massive obstetric haemorrhage (MOH) is a leading cause of maternal morbidity and mortality world-wide. Using the Australian and New Zealand Massive Transfusion Registry, we performed a bi-national cohort study of MOH defined as bleeding at >/=20 weeks' gestation or postpartum requiring >/=5 red blood cells (RBC) units within 4 h. Between 2008 and 2015, we identified 249 cases of MOH cases from 19 sites. Predominant causes of MOH were uterine atony (22%), placenta praevia (20%) and obstetric trauma (19%). Intensive care unit admission and/or hysterectomy occurred in 44% and 29% of cases, respectively. There were three deaths. Hypofibrinogenaemia ( /=6 RBC units before the first cryoprecipitate (odds ratio [OR] 3.5, 95% CI: 1.7-7.2), placenta praevia (OR 7.2, 95% CI: 2.0-26.4) and emergency caesarean section (OR 4.9, 95% CI: 2.0-11.7) were independently associated with increased risk of hysterectomy. These findings confirm MOH as a major cause of maternal morbidity and mortality and indicate areas for practice improvement.