The prevalence of rare GCK variants in the screened GDM subgroup was 1.9% (9/474).<h4>Conclusion</h4>The low prevalence (1.9%) of rare GCK variants and absence of confirmed GCK-MODY cases indicate limited utility of fasting glucose-based screening for GCK-MODY in Chinese GDM populations. This evidence concerns the gene GCK and gestational diabetes.