Queensland (SERC) provided funding for ROTEM® testing and consumables; National Blood Authority Australia, Australian Society of Anaesthetists, and The RBWH and RBWH Foundation provided funding for research nursing support and time to conduct the research. None of these organisations had any involvement in the study design, data collection, analysis interpretation of data or the writing of this report. Conflicts: The authors report no conflicts of interest This study was conducted at The Royal Brisbane and Women's Hospital (RBWH).

ObjectiveThe aim of this study was to establish rotational thromboelastometry (ROTEM®) baseline parameters in labouring women at term gestation. The secondary aim was to compare these reference ranges with those from previous studies on labouring women and from the manufacturer.DesignA prospective, observational study.SettingTertiary referral hospital.ParticipantsHealthy women in labour.MethodsEthics approval was granted for an opt‐out recruitment approach. ROTEM® testing was performed in labouring women at term gestation. Women with any condition affecting coagulation were excluded. ROTEM® Delta reference ranges were derived by calculating the 2.5% and 97.5% centiles for INTEM/EXTEM/FIBTEM parameters including amplitude at 5 minutes (A5), coagulation time (CT) and maximum clot firmness (MCF).Main outcome measuresROTEM® parameters were measured in labouring women before delivery. The following tests were performed: FIBTEM, EXTEM and INTEM.ResultsOne hundred and twenty‐one women met the inclusion criteria, with a mean (± SD) age of 29.6 ± 5.4 years and median (interquartile range) gestation of 39.4 weeks (37.4–40.4 weeks). Seventy‐five (62.0%) women were nulliparous and 71 (58.7%) delivered vaginally. The median and interquartile ranges for selected ROTEM® parameters were: FIBTEM A5, 21 mm (IQR 18–23 mm); EXTEM A5, 55 mm (52–58 mm); and EXTEM CT, 52 seconds (48–56 seconds).ConclusionsThe FIBTEM/EXTEM/INTEM amplitudes were higher than the manufacturer's reference ranges for non‐obstetric patients. The FIBTEM MCF upper and lower limits were higher and the EXTEM/INTEM CT was shorter and narrower in range. This study provides reference ranges for ROTEM® values in healthy labouring women at term gestation with uncomplicated pregnancies.Tweetable abstractThis is the first study to report on ROTEM® reference ranges with over 120 healthy labouring women of normal weight at term gestation.

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