An RNC-OB is a registered nurse who is certified in inpatient obstetric care. Certification recognizes the applied and theoretical knowledge these nurses possess in the obstetric specialty. The National Certification Corporation (NCC) confers certification after a candidate successfully passes an exam. Working in labor and delivery, RNC-OD nurses practice in hospitals and clinics, earning an average of $61,000 annually as of October 2013, according to the Simply Hired website.

Gaining Eligibility

To be eligible for certification, a candidate must currently be a licensed registered nurse in the United States or Canada with two years of work experience in labor and delivery and at least 2,000 hours in the specialty. Additionally, the candidate must have worked in the obstetrics specialty sometime within the past two years.

Taking the Test

Candidates can take the exam on a computer or using paper and pencil at either a professional education center or via the institutional certification plan program. The institutional certification plan program lets institutions have a group of their candidates tested at once, while professional education centers offer courses that culminate in testing. Since the different testing choices have their own policies and procedures, candidates should investigate all the options before applying to take the test.

Test Specifics

After a candidate applies, NCC will send a test outline and resource suggestions. The examination is multiple choice and tests basic and applied knowledge. Almost 30 percent of the questions test labor and delivery knowledge. Another 40 percent of the test is divided among questions on obstetric complications and fetal assessment knowledge. The rest of the questions address maternal factors, postpartum, newborns and professional issues. Candidates have three hours to complete the exam.

Maintaining Certification

A credentialed nurse reestablishes certification every three years either by taking another exam or through 45 hours of continuing education. Continuing education can be accomplished through NCC, universities or organizations established for the purpose. These organizations must be accredited by state boards of nursing, colleges or health care organizations, such as the American Medical Association. To go through NCC, nurses take a knowledge assessment test, which yields an education plan. Course work is available through NCC. The assessment itself provides five hours of continuing education. Other ways to earn hours include teaching courses, writing articles or books and reviewing NCC education modules.