Objective: To understand the experiences of women, birth partners and health professionals of verbal followed by retrospective written consent in a prospective cohort study of a device to manage post-partum haemorrhage (PPH). Design: Grounded Theory. Setting: Tertiary facility in the North-West of England, UK. Sample: We used purposive and theoretical sampling to recruit 51 participants; 12 women, 12 birth partners, 16 obstetricians and 11 midwives. Methods: Semi-structured interviews were conducted, using a topic guide for focus, until data saturation was achieved. Data were analysed using framework analysis technique. Results: Most women wanted sufficient information to make a decision at the time of the event, rather than in advance, and preferred not to be overwhelmed with detail. A key factor in making the decision to participate was a positive and trusting relationship with the attending obstetrician. Obtaining consent for research in emergencies was viewed by obstetricians as requiring a different approach and more challenging than consent for standard procedures in an emergency. Conclusions: This is the first study to explore verbal followed by retrospective written consent processes with women, clinicians and observers. This was acceptable to all, however information needs to be appropriate, and consenters require adequate training. (197/200)