Childbirth, choice & climate change: reducing emissions while preserving pregnant people's autonomy

Background: Nitrous oxide and oxygen mix (gas and air) is a medical gas used for pain relief during labour. It is also one of the largest contributors to greenhouse gas emissions in healthcare. In April 2025, it equated to 13,155 tonnes of CO2 in NHS England, comparable to the emissions of its entire road transport fleet. Gas and air is used by over 70% of the ~450,000 women/people who go through labour each year in England. While clinical use is comparable nationwide, procurement per childbirth varies by up to ten-fold between hospitals. This is indicative of atmospheric emission without clinical use (‘pre-utilisation waste’) arising from supply systems and processes. Furthermore, because gas and air is widely available and easy to administer, it may be given even when not wanted (as reported in our patient and public involvement (PPI) sessions); another potentially important source of waste. Medical gases are amenable to decarbonisation. However, gas and air emissions remain high, despite attempts to reduce its environmental impact. Current research highlights the complexity associated with reducing gas and air emissions, recognising that it is a culturally embedded practice that is low-cost, self-administered and safe. Research aim: To identify and implement key opportunities to reduce the carbon footprint of gas and air in maternity settings whilst maintaining choice and promoting excellent healthcare. Research plan: The project will comprise five interconnected work packages (WPs) informed by ongoing discussions with PPI representatives and a study oversight committee. WPs 1 and 2 will provide a comprehensive understanding of gas and air supply, use and waste. They combine an exploratory, qualitative research methodology with a quantitative analysis of gas systems utilising innovative gas measurement techniques. These WPs will take place concurrently at diverse case study sites, to allow each WP to inform the other. WP 3 involves close collaboration with an expert panel, including pregnant women/people, healthcare professionals, academics and policymakers to co-design and prioritise potential solutions for reducing gas and air emissions. The panel will also determine whether each solution requires a ‘grassroots’ approach (WP4), system-level intervention (WP5), or a combination of both. WPs 4 and 5 draw on consensus methods and a participatory action research approach to achieve transformative change at both local and system-wide levels. Working with diverse people and communities: Our mixed-methods research project brings together members of the public, practitioners and professionals with relevant expertise and experience to ensure that our research is inclusive, appropriate and impactful. Discussions with several patient and public groups have helped to shape our research approach. Knowledge mobilisation, dissemination and impact: We will collaborate with key national and international professional organisations already involved in the project to provide an efficient route to impact and engage with our PPI advisory panel to identify appropriate ways to disseminate our findings. We acknowledge the sensitivity of research involving pain relief in labour and will involve community representatives and media experts in our dissemination strategy from the outset. Decarbonisation will be quantified by using the routinely collected and freely accessible data published on the Greener NHS Dashboard.