WHO: Up to 9.2% of pregnant women. WHAT: temporary diabetic symptoms, including high blood sugar, thirst, frequent urination, blurred vision, and tiredness. WHEN: around the third trimester of pregnancy. WHY: Causes for gestational diabetes are not well understood, but it is theorized that hormones from the placenta block the body's ability to respond to insulin, and may require up to three times as much insulin as normal to function properly. If this diabetes is not managed well, the baby may become very fat before being born, leading to increased risk of developing diabetes, obesity, and breathing problems. See your doctor about treatment options for this condition, and consider making plans to incorporate more exercise and a healthier diet into your lifestyle.