A nurse can work in many different medical areas, while a midwife works only in labor and delivery. Nurses are required to receive formal education and certification, while midwives are not. Nurse-midwives have the formal education of a nurse and the hands-on experience of a midwife.
Midwife
A midwife is trained to help pregnant women deliver their babies. Midwives have been around for centuries, though formal training for midwives is relatively recent. A certified midwife (CM) typically receives a license to practice midwifery. A lay midwife performs the duties of a CM but is not formally licensed. Finally, a certified professional midwife (CPM) is certified by the North American Registry of Midwives. All midwives help women during labor and delivery. They also evaluate the mother and baby postpartum. If either patient requires further medical attention, they must go to a hospital, since a midwife does not have professional medical training to handle such cases.
Nurse
A nurse, on the other hand, can work in a wide variety of medical specialties--not just labor and delivery. A labor and delivery nurse works in the same medical field as a midwife; however, a nurse can only assist the obstetrician. A nurse is not authorized to perform the entire delivery, except in emergency situations.
Required Training Nurses must attend either nursing school or a regular university and receive a degree in nursing. Nurses must also pass licensing exams to become a registered nurse (RN). CMs must meet minimum requirements to receive a midwifery license. CPMs must pass exams and must log sufficient hands-on hours to receive this more advanced certification. Lay midwives receive no formal training at all.
Nurse-Midwife
Some nurses opt to become nurse-midwives. A nurse-midwife is a RN with specialized training in labor and delivery. Unlike a regular nurse, a nurse-midwife is authorized perform an entire delivery. Unlike a regular midwife, a nurse-midwife has formal medical training and is a RN. Nurse-midwives can provide much necessary prenatal and postnatal care for pregnant mothers.
Nurse-Midwife vs. Obstetrician Largely, the choice between a midwife and a doctor is a personal one. Opting for a midwife typically means the woman will give birth at home or in another nonmedical setting. Many nurse-midwives also perform home deliveries but have access to hospitals, too. Obstetricians solely perform deliveries in hospitals. Some women argue that the home environment is a more comfortable and natural place to give birth. Other women argue that access to a hospital's onsite medical technology and medical professionals should not be sacrificed for comfort.
Warning
It is important to note that seeing a midwife exclusively is not recommended for high-risk pregnancies. Women who have had a previous cesarean section, are having multiples or have preeclampsia are all examples of high-risk pregnancies. Nurse-midwives often work with doctors, but midwives who work alone might not. It is best for women to see a doctor early in their pregnancies to determine whether they are high-risk.

Specialist practice: are there differences between nurses and midwives? (6kb) British Journal of Nursing, Vol. 5, Iss. 8, 25 Apr 1996, pp 466 - 466

The UKCCs (1994a) postregistration and practice requirements for all health-care professionals came into effect in April 1995. They were formulated to provide a coherent, comprehensive framework of education and practice beyond registration, and to encourage some practitioners to move along a continuum from registered practice through specialism and onto advanced practice. However, 1 year on, concerns are beginning to arise. The continuum model is applicable to all practitioners except midwives who are viewed as meeting the requirements of specialist practice by virtue of their postregistration educational activities, which include a statutory requirement for continuing education. The UKCC believes that