Risk-based screening test for gestational diabetes in a population-based cohort

Introduction: Gestational diabetes (GDM) is one of the common pregnancy complications with increasing incidence worldwide. Distinct from universal screening, the UK established risk factor-based GDM guidelines. However, low compliance to the NICE guideline in clinics are considered missed opportunities to treat women with GDM. Our study aims to quantify the implementation of GDM screening in a UK population-based cohort of general practices.

Methods: We used data from the Clinical Practice Research Datalink and Hospital Episode Statistics. Our study cohort included pregnancies identified between January 1, 2000 and March 31, 2017. We excluded those with less than 1- year of registration time, history of diabetes, and age< 15 or age >45 years old. Risk factors include minority ethnicity, maternal obesity (BMI ≥ 30 kg/m2), history of having macrosomic baby, family history of diabetes, history of gestational diabetes identified using read code or ICD codes. We grouped glucose-related tests as urinary glucose test, HbA1C, oral glucose tolerance test (OGTT), blood glucose test. Non-compliance to NICE guidelines were defined as no screening test prescribed during pregnancy among women with risk factors.

Results: The final analytic cohort included 299,353 pregnancies, with 18% pregnancies from women with at least one risk factor. We found the overall non-compliance was 36% in our cohort and did not vary by years. Among all glucose tests, urinary glucose test was most widely prescribed during pregnancy; HbA1C test was prescribed mostly in early trimester. Only 32% of women were prescribed either OGTT or blood glucose test.

Conclusion: Our preliminary results show the clinical implementation for GDM screening was inconsistent with the guideline. Next, we aim to explore the clinical characteristics related to screening test prescription after accounting for the differences between general practices. These results could help inform the public on the state of GDM screening in the UK, relative to set guidelines.