From what I understand - I work with an x-prenatal nurse and the difference between a Certified nurse midwife and O.B. isn't much of a difference until it comes to delivery. A Midwife specializes in Natural child birth - no drugs! In my O.B. practice that I go to they have 6 different doctors and you will see all of them plus one certified nurse midwife which I saw at my last appointment (when we heard the heartbeat.) Ladies please correct me if I am wrong, because I am not 100% sure. Hope I was some help to ya Sarah!