I had it with my son, don't have it this time...so they say but I can tell otherwise. I just monitored my sugar levels and kept watch of what I ate and drank. My son was 6lbs when he was born. It affects every pregnancy differently, but don't be too concerned until you talk to an expert. Ask questions.
I was recently diagnosed and freaking out about it, but I went to my diabetic counseling class Monday and feel do much better about it. Basically it means your body has a harder time producing insulin to break down the sugar in your blood. If untreated your baby will be bigger, have pancreas and liver problems and worse case scenario be stillborn or die shortly after birth, but like I said, that's the absolutely worse case if gone untreated. As long as you monitor your blood sugar and follow the diet plan you're given you and baby will be absolutely fine. Don't worry.
I dont know the technical term or whatever but it has something to do with how your body processes sugar and the insulin in your body. While your pregnant. Ive recently got diagnosed with it as well. But end result is bigger babies meaning could end up on c section, your baby could also come out with low blood sugar which isnt good either. But you can still have a healthy baby. Thats why its important to know and to eat the proper diet if diagnosed. Hope that helps.