A third of women who get diabetes while pregnant – a common condition called gestational diabetes mellitus or GDM – will go on to develop type 2 diabetes within 15 years of their pregnancy.
The figures show that the risk of developing type 2 diabetes after a pregnancy with GDM is much more variable than previously thought and persists into later life.
This research is from the Prevention Group which spans the MRC Epidemiology Unit and Primary Care Unit within Cambridge Population Health Sciences.
Gestational diabetes mellitus (GDM) is one of the most common conditions of pregnancy, affecting up to 13% of pregnancies across the world. It is becoming more common, because of increasing levels of obesity, sedentary lifestyles and unhealthy diets. Although most women no longer have diabetes after they have given birth, GDM is known to be associated with future risk of developing type 2 diabetes mellitus (T2DM).
This new study is the largest and most comprehensive systematic review of all the available data from studies published up to October 2019. It provides the best available estimate of the risk of T2DM after having GDM and explores reasons for the variation in risk.
Dr Becky Dennison, lead author at the Primary Care Unit in Cambridge, suggests that the new figures should be used by clinicians and healthcare planners to inform care for women who have experienced GDM.
Dennison points out that the risk of getting T2DM, for women with GDM, is similar to the risk for people with so-called pre-diabetes (when blood glucose levels in the body are raised but below the diagnostic level for diabetes). People with pre-diabetes are invited for regular testing and to take part in the NHS Diabetes Prevention Programme.
The new figures indicate that there is a strong case for testing for diabetes, not only straight after a GDM-affected pregnancy but regularly thereafter, for the long term. Dennison also suggests that patients themselves should be made aware of the risk so that they can take up testing opportunities and seek support, if needed, to make healthy lifestyle changes.
Unlike previous research that suggested risk plateaued over time since pregnancy, these findings show that the number of women diagnosed with T2DM increases each year after their pregnancy with gestational diabetes. The figures underline the need for regular blood glucose monitoring over time.”
– Professor Simon Griffin, Professor of General Practice, University of Cambridge, and co-author
This study was part of Dr Becky Dennison’s PhD research programme on gestational diabetes mellitus and was funded mainly by the National Institute for Health Research (NIHR) School for Primary Care Research.
Read the paper
R Dennison, E Chen, ME Green, C Legard, D Kotecha, G Farmer, S Sharp, RJ Ward, JA Usher-Smith, SJ Griffin, The absolute and relative risk of type 2 diabetes after gestational diabetes: A systematic review and meta-analysis of 129 studies, in Diabetes Research and Clinical Practice, 15 December 2020. https://doi.org/10.1016/j.diabres.2020.108625
Read more about Dr Dennison’s research