BUT - they cannot just "go ahead" and do anything without consent unless the mother was unconcious. Well thats how it is at my hospital. They cannot administer drugs without consent as the patient could very well be allergic. If they did they would be up for a law suit! Though in saying that there are circumstances where the risk to mother and baby can out weigh the consent thing.
Unfortunately, these things have happened to BB women- procedures done without consent, drugs given without consent. And actually proceeding with a law suit is so incredibly difficult that it rarely happens.

A woman should always have the right to refuse medical treatment.