A good general question that is unlikley to be answered in the interview (as they do give you alot of info aswell as ask you questions) is 'what are the further training opportunities in the Trust?' show you are thinking ahead and keen to learn, it maybe they offer ALSO training after so many years service etc.... even better ask about ALSO training
(advanced life support training in obstetrics)
http://www.also.org.uk/ have a look