pGCD59 (<14 WG) prediction of GDM status (24–28 WG) by BMI categories - adjusted ROC curves for maternal age, BMI, maternal ethnicity, parity, previous GDM, family history of diabetes and week of gestation at pGCD59 sampling at Galway University Hospital, Galway, Ireland between November 2018 and March 2020, n = 378. A: BMI < 25 m/kg2, AUC: 0.60 95 %CI: 0.48–0.73; B: 25 kg/m2 ≤ BMI < 30 kg/m2, AUC: 0.65 95 %CI: 0.53–0.78; C: 30 kg/m2 ≤ BMI < 35 kg/m2, AUC: 0.70 95 %CI: 0.56–0.83; D: 35 kg/m2 ≤ BMI < 40 kg/m2, AUC: 0.85 95 %CI: 0.70–0.98; E: BMI ≥ 40 kg/m2 AUC: 0.88 95 %CI: 0.63–0.99.