You have to have your bladder full for the good visibility. You can drink less but be prepeared to be asked to drink more and wait. It is true, there is no one size fits all, but you have to have a very full bladder. You can try to drink a little less but try to avoid going to the bathroom for a while after you drink.
FYI: in most places they do not ask pregnant womans do that since they use tranvaginal u/s. However you may need to have abdominal for whatever they are trying to look for - I do not know.
FYI: in most places they do not ask pregnant womans do that since they use tranvaginal u/s. However you may need to have abdominal for whatever they are trying to look for - I do not know.