Rotational thromboelastometry (ROTEM®; Instrumentation Laboratory™, Munich, Germany) is a point-of-care visco-elastic test of coagulation that is well established in hepatic and cardiac surgery, obstetrics and trauma.1,2 Women become more hypercoagulable as pregnancy progresses through the three trimesters and this has been measured by both thromboelastography and rotational thromboelastometry in uncomplicated pregnancies.3 To date there has been a paucity of substantial, well-researched reference ranges for ROTEM® in pregnant labouring and non-labouring women.