I don't see why you wouldn't able to get pregnant with gastritis....Although many of the causes are related to infection (bacterial and/or fungal)...Of course there are other causes as well which I'm sure you already know if you have it.....So I would say that if you know the source of your condition and it's not infection related, pregnancy would not be an issue.....of course if it is infection reltated, this can cause harm to the fetus.
gastritis, if I've got the right thing is an inflamation in your intestions?