UNPRECEDENTED RATES OF PPH: A PROSPECTIVE OBSERVATIONAL COHORT STUDY OF BLOOD LOSS IN CHILDBIRTH (THE STOP STUDY) Women’s Health Academic Centre A. Briley* 1, P.T. Seed 1, H. Ballard 1, G. Tydeman 2, M. Waterstone 3, R. Tribe 1, J. Sandall 1, S. Bewley 1 1 Women's Health Academic Centre KHP, London; 2 NHS Fife, Kirkcaldy; 3 Dartford and Gravesham NHS Trust, Dartford. Introduction Postpartum haemorrhage (PPH) > 500 ml is common, easily treatable and remains a major cause of morbidity. UK Confidential Enquiries and Scottish Severe Morbidity Audits demonstrate high rates of substandard care. Aims To investigate the incidence, prediction and progression of PPH to severe PPH. To identify changes by comparison with historical data from the same geographical data. To compare contemporaneous data with another UK region. Methods Minimal anonymised data from 10,213 women delivering in one teaching and one district hospital units between 1/8/08-31/7/09. Data prospectively imported into a secure internet based data management system from NHS electronic records. A weighted sampling strategy provided a representative sample set to assess PPH. 1,851 notes were reviewed. The sample was selected using numbered dice and the ordering recorded. Further cases were identified through blood transfusion records. Ambiguous cases and 10% of all notes were independently reviewed. Multiple logistic regression with hierarchical ordering of variables was used to predict PPH >500ml and progression to severe PPH >1500 ml. Severe PPH incidence was compared with an earlier case-control study from the same geographical population (COSMO ) (1). Blood loss > 2500 ml was compared to the Scottish Confidential Audit of Severe Maternal Morbidity (2). Results Main risk factors for progression of PPH included previous PPH and Caesarean section (CS), abnormal placentation (retained and praevia), and sepsis. Conversely, multiparity and prophylactic administration of syntometrine™ for the third stage protected against PPH progression. Comparison with data from the same geographical population 11 years earlier (1) shows a 19.8% increase in births (8,329 to 10,213), a 4.2 fold increase in number of PPH > 1500ml (93 vs 391) and a 3.5 fold in incidence (1.12% [95%CI 0.92 to 1.38] vs 3.8% [95%CI 3.5 to 4.2]). Acknowledgement Guys and St Thomas’ Charity funded this work. Registered charity number % Incidence PPH ≥ 2500ml Year References (1) Waterstone M, Bewley S, Wolfe C. Incidence and predictors of severe maternal morbidity. BMJ 2001; 322: (2) The Scottish Confidential Audit of Severe Maternal Morbidity:7 th Annual Report (data from 2009). Healthcare Improvement Scotland Figure 1: Incidence of PPH > 500 ml in STOP study is 34% Figure 2: Overall incidence (%) blood loss by category for women delivering in STOP study Table 1: Risk factors for progression to severe PPH Figure 3: Time trend in the Scottish Audit and COSMO/STOP data for blood loss > 2500 ml (Major Obstetric haemorrhage (MOH). Discussion Although consistent with other time-trends, this prospective observational study reports unprecedented levels of PPH and severe PPH rates - the highest in the literature. The rigorous assessment of data highlighted errors in assessment and documentation of blood loss, and this mitigates against the findings being due to ascertainment bias. A web-based audit and feedback tool that is not onerous for clinicians could facilitate ongoing contemporaneous evaluation of incidence, management and innovation in treating PPH. This might fill the gap between local near-miss audits and national level data (CEMD, UKOSS, Scottish Audit) with their inherent limitations. Services need to focus urgently on PPH. Multiparous