The aim of this study was to compare pregnancy outcomes of Chinese women diagnosed with gestational hyperglycaemia by the well-established American Diabetes Association (ADA) criteria, with those women meeting the newer criteria established by International Association of Diabetes and Pregnancy Study Groups (IADPSG). The study subjects consisted of 6,201 pregnant Chinese women with a singleton pregnancy who had received prenatal care and delivered between December 2008 and December 2011. Women who were screened positive with 1 h glucose load of >= 7.8 mmol/l underwent a diagnostic 3 h oral glucose tolerance test. Gestational hyperglycaemia was diagnosed using the ADA criteria and re-diagnosed according to the IADPSG criteria. The correlation between the incidences of adverse pregnant outcomes with gestational hyperglycaemia was analysed. In total, 570 patients (9.19% of 6,201) met the ADA criteria and 676 (10.90% of 6,201) met the IADPSG criteria. The 518 patients who met both standards showed a reduced caesarean section rate, as compared with 158 patients who only met the IADPSG standard and received no intervention (71.2% vs 79.7%, p < 0.05). The IADPSG-only group also had a higher rate of macrosomia and pre-eclampsia than the control group. The IADPSG criteria identified a group of women previously classified as normal according to the ADA criteria, but revealing poor pregnancy outcomes and requiring management. Therefore, we conclude that the IADPSG criteria are more suitable for the diagnosis of gestational hyperglycaemia in China.