T.S.
I have a 3 month old at home and was thirsty throughout my pregancy the whole time. I actually craved ice. Would stop by McD's or BoJo's and just order large cups of ice if I was on the road......I had Gest Diab as well (controlled it with diet and pills) and as soon as I had my son (I was also induced early because of - which was good...cause had 9lb 11ozer 2 weeks early). Sugar levels got back to normal after delivery and no longer crave the ice....but Breastfeeding seems to keep me wanting water as well. So just stick to drinking what is good for you!!
Good Luck