Monitoring blood sugar levels in pregnancy: comparing continuous glucose monitoring with finger-prick testing for gestational diabetes

Plain English summary of protocol

Background and study aims
Gestational diabetes mellitus (GDM) is a condition where blood sugar (glucose) levels become too high during pregnancy. Around 1 in 5 pregnant women in the UK develop GDM and this number is increasing each year. GDM is more common in women from minority ethnic backgrounds and those living on lower incomes. It can cause serious problems for mothers and babies, including early birth, babies growing too large or too small, admission to neonatal intensive care, and stillbirth or newborn death. Detecting and managing blood sugar levels reduces these risks and can lower costs to the NHS.

Currently, women with GDM monitor their blood sugar using finger‑prick tests, also called Self Monitoring of Blood Glucose (SMBG), several times a day. This can be painful and inconvenient and only provides limited information, leading to missed chances to reduce complications from GDM. Continuous Glucose Monitoring (CGM) could be a solution. CGM uses a small sensor worn on the arm to measure blood sugar continuously and send readings to a smartphone or reader. It is painless and provides blood sugar level information 24 hours a day that could help healthcare staff and women to lower blood sugar levels and reduce pregnancy complications.

The RECOGNISED study will recruit pregnant women with GDM from 25 UK maternity centres. Participants will be assigned to one of two groups by randomisation, ensuring both groups are similar. One group will monitor their blood glucose using SMBG (usual care) and the other group will use CGM. RECOGNISED will assess whether monitoring blood glucose using CGM improves outcomes for mothers and babies, reduces NHS costs, and is acceptable to women and healthcare teams, when compared with the current standard of care (SMBG).

Who can participate?
Pregnant women diagnosed with GDM with no other forms of diabetes, and who are being cared for at any hospital participating in the RECOGNISED trial.

What does the study involve?
Patients who agree to take part will be randomly assigned to monitor their blood glucose using SMBG or CGM until delivery. Participants will be asked to complete questionnaires when they are enrolled, at 34 weeks gestation and at 13 weeks postnatal. Usual care (SMBG) participants will additionally wear a blinded CGM sensor at enrolment and at 34 weeks gestation for two weeks. Some participants will have an additional blood test at 34 weeks gestation to measure HbA1c if that was not previously done as part of their usual care. The research team will also collect routine medical data for the participant (mother) and their baby from randomisation to 13 weeks postnatal. Participants may also take part in an interview to discuss their experiences of the study if they wish to.

What are the possible benefits and risks of participating?
Participants are unlikely to receive any direct benefit from taking part. However, the information collected may help researchers and healthcare professionals better understand different methods of monitoring blood glucose in women with gestational diabetes, which could improve care for future patients.
Participants may experience minor discomfort from using the sensors (e.g. bruising or skin irritation). There is a possibility of sensor malfunction or inaccurate readings, which may require temporary use of finger-prick blood glucose testing instead. Some questionnaires include questions about wellbeing and mental health, which some participants may find upsetting or distressing.

Where is the study run from?
The Bristol Trials Centre, a UK Clinical Research Collaboration registered Clinical Trials Unit, which is part of the University of Bristol’s Medical School, UK.

When is the study starting and how long is it expected to run for?
January 2027 to April 2029. Recruitment to the study is expected to start in January 2027 and will continue for 22 months. Following this, there will be 6 months of follow-up, so the study results will not be expected until the end of 2029.

Who is funding the study?
The National Institute of Health and Social Care Research (NIHR) – Health Technology Assessment Programme (NIHR-HTA), UK.

Who is the main contact?
The central trial team, recognised-study@bristol.ac.uk

Contact information

Study information

Eligibility

Locations

Countries of recruitment

• United Kingdom
• England
• Wales

Study participating centres

Results and Publications

Editorial Notes

02/11/2026: Study's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).