By PPH Foundation
When a flood, storm or other climate-related disaster strikes, attention naturally turns to the immediate needs of affected communities: injuries, displacement, food, water and shelter. But another critical system can also come under pressure, one that is less visible until a patient urgently needs a transfusion: the blood supply.
For a woman experiencing postpartum haemorrhage (PPH), this matters because severe bleeding can require rapid access to safe blood and blood components. A climate-related emergency can disrupt several links in the chain that makes that access possible, from blood donation and collection to testing, storage, transport and delivery to health facilities.
A 2025 review published in The Lancet highlighted climate change as a growing threat to the blood supply chain. The authors noted that extreme weather events, changing patterns of infectious diseases and temperature fluctuations can affect blood collection, testing, transport and storage, potentially threatening both the availability and safety of blood products (Fakih et al., 2025).
The disruption can begin with donors. A disaster may prevent people from reaching blood donation centres, while displacement, illness or the closure of collection sites can reduce the number of available donors. At the same time, an emergency may increase demand for blood because of trauma and other urgent medical needs.
Research on disasters has shown how vulnerable blood services can become during major emergencies. A 2022 systematic review found that natural and other disasters can affect blood donation and blood safety, although the available evidence was too varied to establish a single predictable pattern in donation levels (Laermans et al., 2022).
The problem does not end with collecting blood.
Blood must be tested, processed, stored under appropriate conditions and transported safely. Climate disasters can damage infrastructure, interrupt electricity, affect refrigeration, disrupt communication and make normal transport routes unusable. WHO guidance on emergency blood supplies specifically identifies risks to donors and donations, testing and processing, storage and distribution, including the availability of temperature-controlled storage and transport capable of reaching hospitals when normal routes are unavailable.
For maternity services, this means that a facility may face an emergency at precisely the moment when the wider blood system is under strain.
Prof Julius Ogeng’o, Co-Lead of the End Postpartum Haemorrhage Initiative, has emphasised that access to blood should not be viewed simply as a hospital responsibility. “Blood access is not simply a clinical supply issue; it must be a family and community priority. When families plan ahead, know blood types, and engage with blood donation systems before delivery, we see faster responses and lives saved.”
His message takes on an additional significance during climate-related emergencies. If disasters can disrupt donor access, transport, storage and health-facility operations, blood security requires preparation before the emergency occurs.
WHO recommends that blood services develop emergency and business-continuity plans that assess local risks and prepare for possible disruptions to supply, equipment, staffing, transport and demand. It also stresses that resilience requires coordination between blood services and the wider health system.
Recent research from low- and middle-income countries similarly identifies workforce capacity, infrastructure, stock and supply readiness, communication, coordination and partnerships as important components of preparedness for climate-related disasters.
This is particularly important for PPH because maternal haemorrhage does not wait for normal services to resume. A woman can begin bleeding during a flood, after a storm or while a health system is dealing with several competing emergencies.
Building climate-resilient blood systems therefore means thinking beyond the blood bank itself. It means maintaining reliable cold-chain systems, protecting equipment and power supplies, strengthening communication, preparing alternative transport arrangements, maintaining trained personnel and ensuring that blood can be moved quickly when normal systems are disrupted.
Climate change may not directly cause a woman to develop PPH, but it can influence how prepared the health system is to respond when PPH occurs. For a woman who is losing blood, the resilience of that system can become just as important as the treatment being provided at her bedside.
References
Fakih, A., et al. (2025). Blood under pressure: How climate change threatens blood safety and supply chains. The Lancet.
Laermans, J., O, D., Van den Bosch, E., De Buck, E., Compernolle, V., Shinar, E., & Vandekerckhove, P. (2022). Impact of disasters on blood donation rates and blood safety: A systematic review and meta-analysis. Vox Sanguinis, 117(6), 769–779.
World Health Organization. (2023). Guidance on ensuring a sufficient supply of safe blood and blood components during emergencies. Geneva: WHO.
World Health Organization. Strengthening blood systems and regulations. WHO Health Products Policy and Standards.
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