OP you are heartless. You say you're in a committed relationship with this girl and have been trying to concieve for a baby, planning a future together?
And yet when she receives heartbreaking news by any standard for women who want children, that her womb will probably be unable to play host to a child, and your first though is *dump her* ?
If you even cared the slightest about your partner, you would be thinking about ways to help her through this difficult time, she must be hurting. Obviously you want children and that's great, and you shouldn't be denied them, but there are so many other options. Modern medicine is so advanced and she could even become pregnant naturally.
By the way your post is worded, it doesn't seem you care about who you have children with, just that you get them, this is no way to start a family.
If you have any shred of decency, remember your partner and how she must be feeling, if you love and care for her, then that should be enough to stay with her. It isn't a difference of opinions here between you and her, think about how awful she must feel that she can't give you what you want/need, and console her.