Using lactate testing to improve maternal sepsis identification: a multi-country test accuracy study and feasibility assessment Maternal sepsis is a medical problem caused by infection during or after pregnancy or childbirth. It occurs when the body's response to infection starts to cause damage to its own organs and tissues. It can be life-threatening if not identified and treated quickly after it has developed. In fact, worldwide it is the 3rd most common cause of death related to pregnancy and childbirth. Internationally, organisations such as the World Health Organisation and United Nations are committed to reducing the numbers of women who die from preventable causes related to their pregnancies. Tackling maternal sepsis is an important part of this effort.  In high income countries research has shown that groups of key treatments given together at the same time can help reduce bad outcomes and deaths from sepsis. These groups of treatments are sometimes called "treatment bundles".   Because of this research, and the importance of tackling maternal sepsis worldwide, a treatment bundle was developed specifically for maternal sepsis. This treatment bundle is called FAST-M and was developed to be used in resource-poor settings and been tested in lots of facilities so we know it can be used to improve care.   The next important research question our team would like to answer is in which women the FAST-M treatment bundle should be started. In high income settings and the general adult population, a blood test is commonly used to help gauge which patients are most unwell from sepsis and at risk of poor outcomes. This blood test measures an acid in the blood called Lactate, which is a helpful test to identify people who need the most urgent treatment. A small hand-held machine can now be used to measure Lactate which means it could be used even in placed that don't have proper laboratory facilities.  However, it is not currently known what happens to lactate when a pregnant or recently pregnant adult has an infection, or if the test works as well if used in low resource setting. Changes in the body around pregnancy and childbirth alter how the body responds to infection which may also alter how the test works. Our team wants to find out if using a rapid lactate test is better than routine observations in identifying women most likely have maternal sepsis and to suffer poor outcomes.   We intend to conduct this research in 3 countries; Malawi, Pakistan and Uganda. We will identify cases of maternal infection within the hospital sites. After gaining the permission of these women we will add taking a blood sample for lactate testing. We will not change the usual treatment but follow what happens to these women till they are discharged from hospital. We will look at the results of the lactate test, compared to usual observations to see how it compares in diagnosing maternal sepsis, and in predicting poor outcomes.   In the second part of the study we want to find out if using this lactate test as part of maternal sepsis care, linked to the FAST-M bundle is possible in low resource settings, and what makes this easier or more difficult. To do this we will use sites in Uganda and Pakistan and see how it Lactate testing works when used. We will look carefully at how staff find using it by measuring what happens to patients and if it has been used correctly and reliably. We will also give questionnaires to staff and talk in detail to healthcare workers and others in the facility to find out their opinions about the test.  This research will help us to know if using the lactate blood test is useful to diagnose cases of maternal sepsis and how the testing can be used in resource limited facilities to improve care. We hope this information will help reduce deaths and poor outcomes from cases of maternal sepsis worldwide. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.