Ascertainment of gestational diabetes mellitus (GDM)
Participants underwent a 75-g oral glucose tolerance test (OGTT) at 24-30 weeks’ gestation; fasting (FG), 1-h plasma glucose (1hPG) and 2-h plasma glucose (2hPG) concentrations were obtained using an automated biochemical analyzer (Abbott Alinity). Plasma glucose concentrations were used to classify GDM according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria: if any one of the plasma glucose values was at or above the following thresholds: 5.1 mmol/L for FPG, 10.0 mmol/L 1hPG and 8.5 mmol/L for 2hPG.