Developing and evaluating an online learning tool to improve midwives' accuracy of visual estimation of blood loss during waterbirth: an experimental study

This Journal article is part of Staff Publications

This publication is embargoed and will be available as Open Access on 2019-10-17.

Manuscript details


Objective. The principal objective was to test the effectiveness of an online learning tool to improve midwives’ accuracy of blood loss estimations in a birthing pool environment. The secondary objective was to assess the acceptability of the online learning tool to the midwives using it. Design. A one group pre-test post-test experiment with immediate and six weeks follow-up to test ability together with an online questionnaire to assess perceived usefulness of an online learning tool. Setting. A large NHS maternity hospital comprising an acute care obstetric unit, a small district unit labour ward, one alongside midwifery-led unit and three freestanding midwifery-led units. Participants. Volunteer NHS employed midwives who had experience in caring for women labouring and giving birth in water (n=24). Intervention. An online learning tool comprising six randomly ordered short video simulations of blood loss in a birthing pool in real time, and a tutorial giving verbal and pictorial guidance on making accurate blood loss estimations in water was developed then piloted. Midwives’ accuracy scores for estimating blood loss in each of the videos were calculated at three timepoints; pre and immediately post the learning component, and six weeks later. The estimated blood loss volume was subtracted from the actual blood loss volume, to give the difference between estimated and real blood loss in millilitres(ml) which was then converted to percentage difference to standardise comparison across the six volumes. The differences between pre- and post-learning for each of the six blood volumes was analysed using a repeated measures ANOVA. Statistical significance was set at p<0.05. An online questionnaire incorporated questions using Likert scales to gauge confidence and competence and free text. Free text responses were analysed using a modified form of inductive content analysis. Findings. 22 midwives completed the online learning and immediate post-test, 14 completed a post-test after six weeks, and 15 responded to the online questionnaire. Pre-test results showed under-estimation of all blood loss volumes and particularly for the two largest volumes (1,000 and 1,100 ml). Across all volumes, accuracy of estimation was significantly improved at posttest 1. Accuracy diminished slightly, but overall improvement remained, at post-test 2. Participants rated the online tool positively and made suggestions for refining it. Key conclusions and implications for practice. This is the first study measuring the accuracy of midwives’ blood loss estimations in a birthing pool using real-time simulations and testing the effectiveness of an online learning tool to improve this important skill. Our findings indicate a need to develop interventions to improve midwives’ accuracy at visually estimating blood loss in water, and the potential of an online approach. Most women who labour and/or give birth in water do so in midwifery-led settings without immediate access to medical support. Accuracy in blood loss estimations is an essential core skill.


Ethel Burns
Louise Hunter
Zoe Rodd
Megan MacLeod
Lesley Smith


Faculty of Health and Life Sciences


waterbirth, blood loss estimations, video simulations, online learning tool, experimental study, longitudinal

Version of record




Burns, E., Hunter, L., Rodd, Z., MacLeod, M. and Smith, L. () 'Developing and evaluating an online learning tool to improve midwives' accuracy of visual estimation of blood loss during waterbirth: an experimental study', Midwifery, 68, pp.65-73. DOI: 10.1016/j.midw.2018.10.004.