GCK and Impaired glucose tolerance: Postpartum, three of the four women with pre-GDM responded to sulphonylureas (SU) whereas one continued on insulin(PDX1); additionally, of the five MODY subjects with overt diabetes in pregnancy who underwent a follow-up oral glucose tolerance test, two of these subjects with PDX1, NEUROD1 progressed to develop diabetes, two subjects with INS, PDX1 showed impaired glucose tolerance, one with a GCK gene variant at 12 weeks postpartum reverted to normal glucose tolerance.