Heather,
This surgery is just a tool to help you eat healthy and maintain a "normal" weight range. However, even when you are pregnant, you don't need a lot of extra calories. You can nourish a fetus without over eating or eating more often. That my dear is a myth. You don't really have to eat for two. I had a pregnancy in 2004 where I was pregnant with twin girls, (Courtney Rae & Lindsay Marie) subsequently losing them at 31 weeks from twin to twin transfusion syndrome. I only gained about 9 lbs throughout the pregnancy because I was very sick but that is not what caused the fetal demise, the doctor said that I didn't have to gain that much weight in order to maintain fetal health. You don't have to stretch the pouch. Many people who have the surgery end up having healthy babies. As a matter of fact, it helps people with fertility problems to end up getting pregnant. I don't know if this helps or not, but I know in my case.. as I am getting older I am anticipating hopefully having a family some day. Not anytime soon, of course, as I am just 5 months out.. but after I get married..
I am not worried at all about getting the nutrition needed to maintain a healthy pregnancy, as I will be far enough out to be able to get in the protien I need and could always supplement with a shake if needed. Don't worry you'll be fine when your time comes.
Good luck..