Reproducibility of the 75 g oral glucose tolerance test for the diagnosis of gestational diabetes mellitus in a sub-Saharan African population

Twenty-seven of the 84 participants (32.1%) who did the first oral glucose tolerance test were diagnosed with gestational diabetes mellitus. There was no difference between the means of the glycaemic responses at T0 (p = 0.64), T30 (p = 0.08), T60 (p = 0.86), T90 (p = 0.51), and T120 (p = 0.34) between the two oral glucose tolerance test. Age (p = 0.001) and BMI (p = 0.001) were significantly associated with non-reproducible results. The reproducibility of the oral glucose tolerance test in this study was 74.2%, and the kappa statistic's 0.46. In conclusion, the results of the oral glucose tolerance test were reproducible in only 74.2% of pregnant women in this study. This highlights that a single oral glucose tolerance test for the diagnosis of gestational diabetes mellitus should be interpreted with caution.