RECOGNISED - RandomisEd controlled trial of COntinuous Glucose MoNItoring in the management and diagnosiS of GEstational Diabetes Mellitus - a multi centre randomised trial

Research Question: What is the clinical and cost-effectiveness of using continuous glucose monitoring(CGM) compared with usual care for improving neonatal health outcomes in pregnant women with Gestational Diabetes Mellitus (GDM)? Background: The prevalence of women with GDM is increasing(1). Women with GDM can experience serious adverse pregnancy outcomes (neonatal care admissions, large baby, baby deaths)(2,3) despite evidence that improving maternal glucose levels can reduce them (4-7). Standard care for women with GDM is currently self-monitoring of blood glucose (SMBG) with daily fingerpicks (8). This only provides a snapshot of glucose levels and evidence has shown women often don't do it as it is painful and inconvenient(9). CGM which provides a 24-hour picture of glucose levels could allow women and healthcare professionals to closely monitor and improve glucose levels(10,11). There currently are no adequately powered trials of CGM use in GDM pregnancy. Aims: To evaluate the clinical- and cost-effectiveness and acceptability of CGM for pregnant women with GDM. We will estimate differences between groups for adverse neonatal outcomes (primary objective). Additionally, as secondary objectives: 1. for maternal and other neonatal clinical, and maternal diabetes behaviour/health-related quality of life outcomes 2. for cost-effectiveness of CGM compared to SMBG 3. for the acceptability of, and obstacles and facilitators to, CGM use by diabetes treatment satisfaction, maternal quality of life and wellbeing outcomes from qualitative interviews and validated questionnaires to inform future implementation in the wider NHS Methods: 1. An open-label, multicentre, pragmatic, parallel two-group individually randomised superiority trial with internal pilot; nested qualitative study; integrated study within a trial (SWAT) to optimise recruitment of ethnic minority groups; and health economic analysis comparing CGM to usual care for management of GDM. 2116 women with GDM during pregnancy will be recruited from 25 NHS maternity sites including those serving lower income, mixed ethnic minority group to evaluate CGM use for pregnant women with GDM. Women will be randomised to use CGM or SMBG-usual care (1:1 ratio) throughout pregnancy. The primary outcome is a composite outcome of: a) perinatal death (stillbirth/neonatal death =28 days of life), b) Neonatal Intensive Care Unit (NICU) admission, and/or c) large for gestational age (LGA) (> 90th customised birth weight centile). Maternal quality of life and NHS resource use will be measured, and the incremental cost, effects and cost-effectiveness of CGM use will be estimated. Clinical outcome assessments and patient reported outcomes will be measured at baseline, 34 weeks gestation and 13 weeks post-natal. A public-patient involvement (PPI) group will be involved in all stages of trial delivery. Timelines: A 43-month project starting April 2026, with 9m set-up, 22m recruitment (internal pilot 9m), 6m follow-up on all participants, 6m analysis/report/closedown. Anticipated Impact and Dissemination: We aim to publish in high impact journals, present at international/national conferences and disseminate our findings to a broad range of stakeholders. We’ll develop a dissemination plan with our diverse PPI group to provide accessible summary of findings. If results are favourable, we will work with NHS commissioners to implement CGM for all pregnant women with GDM to improve pregnancy outcomes.