PTPRN and Impaired glucose tolerance: In previous studies, risk factors for diabetes or impaired glucose tolerance were BMI before pregnancy,41 42 FPG during pregnancy,41 43 an earlier gestational age at the time of GDM diagnosis,43 the presence of diabetes-related GAD or IA2 antibodies,44 insulin use during pregnancy44 or women with more than two prior pregnancies.44 A systematic review demonstrated other risk factors such as a non-white ethnicity, advanced maternal age and hypertension during pregnancy.45 It may seem obvious that glucose at 6–8 weeks PP is a predictor for glucose at 52 weeks PP.