The impact of inter-laboratory glucose bias on the diagnosis of gestational diabetes mellitus: Comparison of common automated central laboratory methods

•Diagnosis of gestational diabetes mellitus (GDM) relies solely on glucose analyses.•Inter-laboratory bias in venous plasma glucose was low and within desirable limits.•Current automated glucose assays for venous plasma qualify in diagnostics of GDM.•Even low inter-laboratory bias had marked impact on the resulting GDM prevalence.