Yes, even though both a nurse-midwife and a certified midwife have to sit for the CNM certification exam and subsequently obtain certification by the American Midwifery Certification Board (AMCB), a nurse-midwife is quite different from a certified midwife.
The central distinguishing aspect is as advanced practice nurses, nurse-midwives can work in both labor and delivery and general healthcare units; a certified nurse is only limited to practice in labor and delivery.