I also had the GD with my pregnancies, everything came out fine, but two of my kids were a bit bigger than the average baby. Still delivered vaginally, but OUCH!!  My last was the easiest tho, I'm ovo-lacto, so that made things easier, since beans had too many carbs, and I couldn't eat them much at all.  Don't forget to eat plenty of nuts, avacados, and olives.  It was a struggle keeping my caloric intake high enough to keep my weight from dropping, the avacados really helped.  You can do it and still be vegan, I was sick of cheese and eggs after the first couple of weeks, and couldn't have milk due to the lactose, so the last two months I was vegan.