The Leeds Teaching Hospitals NHS Trust

Leeds Maternity Care

MAGiC Research Study

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Understanding the glycemic profile of pregnancy: intensive CGM glucose profiling and its relationship to fetal growth

MAGiC is a multicentre, prospective, observational research study. It is funded by the Medical Research Council (MR/T001828/1) and is being sponsored by the University of Leeds. It has received Research Ethics Committee Approval (REC reference number: 20/YH/0011). The Chief Investigator for the study is Professor Eleanor Scott from the University of Leeds.

The study is taking place in four NHS hospitals across the UK:

  • Leeds Teaching Hospitals NHS Trust (led by Professor Eleanor Scott),
  • George Eliot Hospital NHS Trust (led by Professor Ponnusamy Saravanan)
  • Norfolk and Norwich University Hospitals NHS Foundation Trust (led by Professor Helen Murphy)
  • Manchester University NHS Foundation Trust (led by Professor Jenny Myers)

What is it about?

We want to establish how 24 hour glucose levels change across pregnancy and how they relate to the way babies grow.

Many factors affect the way babies grow in the womb, but one of the most important and easiest to modify, is the amount of glucose that they get from their mother. Too much glucose in their mother’s blood during pregnancy usually leads to a large baby which increases the chance of problems during pregnancy, labour, and immediately after birth. Being born too big, or too small, is also not good for babies’ long term health as it markedly increases the chances of becoming obese and getting type 2 diabetes.

Pregnant women are offered a test (called a glucose tolerance test) to look for high glucose levels developing in pregnancy, but it is done late in pregnancy and relies on taking just two blood glucose readings 2 hours apart after taking a sugary drink. Many women already have signs of abnormal growth of the baby by this stage, so it’s not a good enough test, but we don’t have a better one yet. A mother’s blood glucose changes constantly across the 24 hour day, affected by her daily lifestyle and the pregnancy. It is this daily variation in glucose that affects a baby’s growth but the current glucose tolerance test does not measure this. 

A new way of measuring glucose called ‘continuous glucose monitoring’ (known as CGM) might help. It involves wearing a small sticky patch on the arm (about the size of a £1 coin) whilst going about ordinary everyday life. It is already used in the NHS by people with diabetes, especially those who are pregnant. The patch measures glucose levels every few minutes, day and night for up to two weeks, storing this information. It gives more than 4000 glucose readings over this time, which provides far more detail about what is happening with real life 24 hour glucose levels than the current test. However, we do not currently know how 24 hour glucose levels alter from the beginning to the end of a pregnancy, or how changes in 24 hour glucose levels are related to the way babies grow.

We are approaching 500 pregnant women who have risk factors for developing high glucose levels during pregnancy and who will be having a glucose tolerance test later in pregnancy to help us with this study. Those who participate will wear a small, waterproof CGM on five occasions during pregnancy.

This study will tell us, in detail previously unseen, how glucose changes across pregnancy and how it is related to the baby’s growth and pregnancy outcome. It will tell us whether continuous glucose monitoring can detect glucose abnormalities related to baby’s growth that current tests do not pick up, how common any glucose abnormalities are, when in pregnancy they develop and whether they improve after pregnancy.

If you would like more information about taking part in the study please see our infographic and do contact us:

Viv Dolby – MAGiC Clinical Study Co-ordinator:

Professor Eleanor Scott – MAGiC Chief Investigator: