Unfortunately, there are no obvious signs that's why we have to do screening tests. Every time when you go for your follow up, the doctor will do a urine dipstick test to check. If you have sugar in the urine more than twice the normal amount, then they check for gestational diabetes or the oral glucose tolerance test. Having sugar in the urine can be a normal thing during pregnancy because more blood flows to the kidneys, which doesn't have the time to absorb everything so the sugar passes through in the urine. It doesn't mean your body cannot handle the the sugar level. It is just a filtration absorption thing. Gestational diabetes is not sugar in the urine but an inability to handle the sugar in the blood to metabolize it well. During the follow-up, we usually look out for whether the baby is too big or the water level is too much as signs of diabetes. It is difficult to distinguish between general pregnancy and gestational diabetes symptoms.