Like I said I had gestational diabetes, so I will tell you what happened with me. Don't worry too much as you haven't had your test yet. Wait and see what comes of that first.
I had the challange test and it was slighty elevated so I had the full GTT. This also came back as glucose impaired, so I was treated like I had gestational diabetes. My doctor made me a see a diabetic co-ordinator. I had to go on a special diet and check my sugar levels four times a day. The idea was to keep it below 7. I was able to do this with diet. What happens with gestational diabetes is that the placenta produces a hormone that stops your insulin working as well as it should and so you have higher glucose levels. The glucose crosses the placenta and acts like a growth hormone, hence the bigger babies. By controlling your sugar levels through diet etc, this stops the excess glucose crossing the placenta.
Don't worry though until you have had your test
Mum to DD 08.08.03 and DS 12.05.05