Depending on the experience that you wish to have,,and the location of your birth, you may want to decide what type of midwife you are going to have. A CNM and a CPM are both very trained and effective in doing their job, and I understand that in New Jersey, they also must consult an OB/GYN about your care, especially if they detect a high risk situation.
A Certified Professional Midwife (CPM) is an independent practitioner who has met the standards for certification set by the North American Registry of Midwives (NARM) and is qualified to provide the Midwives Model of Care. The NARM certification process recognizes multiple routes of entry into midwifery and includes verification of knowledge and skills and the successful completion of both a Written Examination and Skills Assessment. The CPM credential requires training in out-of-hospital settings. They normally have a more holistic approach to natural birthing, and do not have a nursing background.
Certified Nurse Midwives (CNMs) provide health care involving emotional and physical support to women before, during, and after childbirth. They are registered nurses with specialized training in assisting pregnant women and their newborn babies. CNMs must complete an accredited program of study and clinical experience in obstetrical care. Certified nurse midwives participate in a variety of services that include providing gynecological services like Pap smears and breast examinations, advising women about reproductive health and personal care, and monitoring the health of the mother and fetus during pregnancy. They also perform complete prenatal care including abdominal and pelvic examinations and evaluations. Another important service that CNMs provide is educating women and their families about childbirth methods, infant care, nutrition, and proper exercise. They work closely with obstetricians and other physicians when medical treatments and medications are necessary.
More definitions can be found at Midwives Alliance of North America.