Mild glucose intolerance (positive urine glucose or mild hyperglycemia) during health checkups in young, lean women may require specialist consultation. We herein report a 31-year-old Japanese woman with mild hyperglycemia detected during a checkup who was diagnosed with overt diabetes in pregnancy and HNF4A-MODY postpartum, without prior follow-up. This case highlights the following: MODY may be present in young, lean women with mild glucose intolerance, and preconception care may improve pregnancy outcomes. Fetal outcomes vary with MODY subtype. Preconception care is important.
Keywords: MODY; medical checkups; preconception care; young lean women.