Real‐world evaluation of the NHS testing criteria for glucokinase hyperglycaemia in pregnancy

Aims Criteria for Glucokinase‐Maturity Onset Diabetes of the Young (GCK‐MODY) genetic testing are now being integrated into the National Health Service (NHS) services using fasting glucose, body mass index (BMI) and ethnicity. We aimed to assess the national screening criteria for GCK‐MODY in a multi‐ethnic population. Methods GCK‐MODY testing was offered to women with gestational diabetes that met criteria in a multi‐ethnic cohort. Data from the national testing centre was used to compare patient characteristics in those positive and negative for GCK‐MODY. Results Fewer cases of GCK‐MODY were found when testing using NHS criteria (0.14%) than expected (0.9%). Individuals testing positive for GCK‐MODY had a higher HbA1c than negative individuals ( p < 0.001). There was no difference in 2‐h glucose increment ( p = 0.829). Conclusions Current criteria may not effectively identify a high‐risk cohort of individuals to test, given the prevalence of GCK‐MODY in those tested, leading to over‐testing. HbA1c may prove a useful additional screening parameter. Further studies are needed to improve the criteria's utility across different ethnicities.