To measure how much of an effect the OBS care bundle has, we will compare numbers of blood transfusions before and after it is introduced. We will also study intensive care admission, hysterectomy and breastfeeding rates. We will also look at effect of the OBS care bundle on the psychological wellbeing of women, birthing people and their partners and how hospitals take on the care bundle. Women and birthing people from ethnic minority backgrounds are affected at an unequal rate by bleeding after childbirth and we will be trying to see whether this can be improved.

Most of the information used in the study will be found using routine NHS data from about 189,000 women and people who give birth in 36 sites over the 45 months of the study. Their data will be included, whether they have excess bleeding or not.

We will also invite a smaller group of women, birthing people and their partners to complete questionnaires and or interviews to understand their experiences of heavy bleeding and if the OBS care bundle changes how teams deliver care. This will also help study the cost of the OBS care bundle.