Gestational Diabetes Mellitus (GDM) is a disease that normally appears during the second half of pregnancy, without any proof of pre-existing type 1 (T1DM) or type 2 diabetes (T2DM). Around 7% of all pregnancies are affected by GDM, with a range of 1 to 14%, based on the study population and the diagnostic tests used. Factors related with an increased risk of GDM include being obese, having GDM during a past pregnancy, having a previous baby weighing 4.5 kg or above, having a sibling or parent with diabetes, or being part of a certain minority ethnic group. A previous GDM diagnosis holds a risk of up to 60% for future T2DM, a fact that highlights the value of screening following labour. The UK guidelines recommend offering a fasting glucose or glycated haemoglobin (HbA1c) test by 13 weeks following birth in women with previous GDM. Women with a negative test result for T2DM following birth should be offered an annual HbA1c test. The rates of screening either shortly after, or in the years following labour in these women, can be used to promote lifestyle changes to prevent the onset of T2DM. This study aims to assess the current screening rates in these high-risk people, and to see if attendance to screening or type of screening test is related with progress to T2DM, heart disease and death. Current study findings will provide helpful information on the update of screening and related factors, since existing evidence in the UK is limited.
This study aims to estimate the proportion of women who attend post-partum follow-up and annual screening and recognise potential key factors that have an impact on these rates. The cohort will include patients with no previous diagnosis of T1DM or T2DM, diagnosed with GDM between 01/01/2000 and 05/11/2018 and having at least 12 months of follow-up. Previous research indicates that GDM is underreported in primary care and using linked primary-secondary care data will add a significant number of GDM cases to our cohort. Evaluation of screening rates and factors associated with them will be investigated in our cohort. In cases where women have GDM in multiple pregnancies, the first pregnancy complicated by occurrence will be used as the index pregnancy. Post-partum follow-up will be defined as any recorded glucose testing within 6 months of delivery. Determinants of screening uptake such as age, time since diagnosis, ethnicity, pregnancy outcome, previous pregnancies, delivery mode, pregnancy complications, ethnicity, smoking status, alcohol intake, deprivation index, body mass index (BMI), mental health and geographic area will be extracted based on the information available within CPRD-HES data. Additionally, we will investigate progression to T2DM based on the type of screening test performed (fasting plasma glucose, HbA1c or oral glucose tolerance test (OGTT)) and long-term cardiovascular and mortality outcomes in women who attended screening compared to those who did not. We will use multivariate logistic regression models to estimate the association of several factors to screening uptake and missing data will be addressed through complete-case analysis and multiple imputation. This study will provide novel and inclusive information about post-partum and annual screening for T2DM in women with previous GDM and the determinants of these rates, which will aid clinicians and healthcare professionals in improving the quality of provided health services.
Post-partum screening rates following GDM; defined as any glucose testing within 6 months of delivery.
Rates of uptake to annual screening following GDM, and whether these are changing over time
Association of uptake to post-partum and annual screening with possible determinants such as age at diagnosis, time since diagnosis, ethnicity, pregnancy outcome, previous pregnancies, mode of delivery, pregnancy complications, ethnicity, smoking status, alcohol intake, deprivation index, BMI, mental health and geographic area.
Progression to T2DM based on the type of screening test performed (fasting plasma glucose test, HbA1c test or OGTT)
Long-term cardiovascular and mortality outcomes in women who attended post-partum and annual screening compared to those who did not.
Kamlesh Khunti - Chief Investigator - University of Leicester
Elpida Vounzoulaki - Corresponding Applicant - University of Leicester
Bee Tan - Collaborator - University of Leicester
Clare Gillies - Collaborator - University of Leicester
HES Admitted Patient Care;Patient Level Index of Multiple Deprivation;Pregnancy Register