This recommendation provides a therapeutic definition of PPH, that is, a diagnostic threshold designed to guide the decision to initiate treatment rather than to define the condition solely for classification purposes. The objective is to support timely clinical action by identifying women at increased risk of adverse outcomes from postpartum bleeding. This approach prioritizes early intervention and the woman’s safety by aligning diagnosis with immediate treatment needs. The recommendation on the time horizon for this definition was informed by evidence showing that most postpartum bleeding events meeting the diagnostic criteria occur within the first 2 hours after birth. However, as life-threatening bleeding can still occur beyond this immediate postpartum period, continued monitoring for clinical signs of concealed or revealed blood loss is essential throughout the first 24 hours postpartum. The GDG acknowledged that the 24-hour time horizon is largely historical and conventional but noted that it also reflects evidence indicating that most acute maternal morbidity and mortality after birth occur within this window, underscoring the need for vigilant observation during this critical period, both inside and outside the labour ward, for optimal maternal care and outcomes.

• Abnormal haemodynamic signs in the context of these diagnostic criteria include any of the following: pulse rate >100 bpm, systolic BP <100 mmHg, diastolic BP <60 mmHg, or shock index >1 (calculated as pulse rate divided by systolic BP, which is >1 when pulse rate is higher than the systolic BP).
• These diagnostic criteria should be linked to the first-response treatment bundle because diagnosing PPH in the absence of timely treatment is unlikely to improve outcomes. The criteria are recommended as the basis for first-response PPH treatment and referral decisions (where needed), not as an absolute trigger for initiating advanced therapies or surgical interventions. Clinical judgement should guide the escalation of care.
• Although this recommendation offers diagnostic criteria for identifying women at risk of adverse outcomes from postpartum bleeding and initiating treatment, it is recognized that health system readiness for postpartum monitoring and treatment initiation (e.g. availability of staff, equipment) varies across different settings. Implementers may choose different thresholds for initiating treatment considering the realities of their local contexts (i.e. earlier intervention and faster escalation if referrals are difficult and time-consuming).
• Wider adoption of these diagnostic criteria may increase demand for basic monitoring equipment (e.g. calibrated drapes, BP devices), and may require additional staff training and resources for objective blood loss measurement and haemodynamic monitoring. However, this investment is offset by reduced demand for expensive, complex interventions for severe PPH that are not available in many settings.
• The diagnostic criteria can be applicable in the context of home-based or community-based births. Adaptations in care may be needed to obtain access to innovative tools for objective quantification of blood loss and monitoring of abnormal haemodynamic signs.
• The risks of bleeding and the signs and symptoms of excessive blood loss should be discussed with women across the birth continuum (including antenatally) to foster shared decision-making and support women in identifying warning signs and promptly seeking care.
• Implementation of the diagnostic test strategy may increase reported rates of PPH, particularly in settings simultaneously introducing objective assessment of blood loss. This should not be interpreted as a decline in care quality but as improved detection and prevention of severe maternal complications.
• The GDG acknowledged that the evidence base overwhelmingly represents facility-based vaginal births, with only one large study of caesarean births included, thus limiting the overall confidence in the generalizability of these criteria to the caesarean birth population. The group agreed that quantitative assessment of intraoperative blood loss can be challenging and changes to clinical signs may be anaesthesia-induced rather than indicative of haemodynamic instability. Nonetheless, the GDG noted that nearly all the components of the first-response treatment bundle that the new diagnostic criteria would trigger are already part of routine care for caesarean birth – uterine massage, oxytocic drugs, intravenous fluids and identification of the source(s) of bleeding – which are often implemented before detection of significant blood loss. The group further emphasized that although the pattern of blood loss may differ according to mode of birth, the physiological impact of a given volume of blood loss, and the associated risk of adverse outcomes, are not expected to differ between vaginal and caesarean births. Consequently, in making this recommendation, the GDG placed its emphasis on the clinical importance of standardized and consistent diagnostic criteria to identify PPH and initiate timely treatment for all births, while recognizing the need for additional research data for the caesarean section population. The GDG also cautioned that the relatively higher blood loss patterns that are associated with caesarean sections should not be normalized or considered acceptable because this may contribute to dangerous delays in intervention, particularly in view of the disproportionately high burden of PPH-related mortality associated with caesarean birth.