Nancy Crippen describes the last hours of labor with her third child as a remarkable contrast to the earlier births of her two sons. This time, instead of dashing off to a hospital, Crippen stayed at home.

On July 30, surrounded by her family and with the support of nurse-midwife Mary Ann Johansen, Crippen gave birth to a healthy girl, whom she and her husband, Joe Gonsornic, named Anna Maria.

"I was very impressed," said Crippen, who lives in Burke. "It was a really good experience. Everything was very calm and the baby was so calm. It was so natural."

When Karen Marcus learned she was expecting her first child, she and her husband Ronald were determined to have the baby at home, with the birth attended by a nurse-midwife.

Last August, with Ronald Marcus and nurse-midwife Joyce Daniel watching, Jeffrey Marcus was born in the bedroom of the Marcuses' Arlington home. "It was the greatest highlight of my life . . . ," Karen Marcus recalls.

Crippen and Marcus are among a small but growing number of women who have decided to use the services of a certified nurse-midwife instead of an obstetrician.

In Northern Virginia, according to Sally Tom of the American College of Nurse-Midwives, there are about 27 certified nurse-midwives, of whom about 16 are currently practicing. In the entire state, Tom said, there are 53 nurse-midwives, and nationally about 2,500.

Each year, Tom estimated, about 66,000, or 2 percent, of all births nationwide are attended by nurse-midwives, and the number of certified midwives is "definitely growing."

"It's a very caring profession, and you and your mate develop an incredible intimacy with the midwives ," said Karen Marcus. "They provide you with not just medical stability and insight and oversight, but with emotional support as well."

Crippen, who was given a general anesthetic and thus was asleep during the births of her first two children, said she felt she was being attended by friends when Anna Maria was born.

"By the time I went into labor, the midwives knew me as a person, not just as someone coming in and out of the door," said Crippen. "Their emotional support was so important."

Crippen chose Annandale Midwifery Associates, run by certified nurse-midwives Mary Ann Johansen and Kathleen Moffitt, while Marcus chose Family Birth Associates of Alexandria, operated by certified nurse-midwives Kate K. Beveridge and Joyce T. Daniel.

Although formal training programs for nurse-midwives began about 1932 in the United States, enrollments began to escalate only in the early 1970s. Under current standards, a certified nurse-midwife must be a registered nurse, usually with experience in obstetrics, who must take special training in midwifery, either through a master's degree or a certificate program.

Nurse-midwives also must be certified by the American College of Nurse-Midwives by passing a written test and must be licensed by the state in which they intend to practice.

Most certified nurse-midwives in Northern Virginia are in private practices, but the bulk of nurse-midwives nationally work in hospitals. In both cases, their focus is on healthy patients who can expect normal pregnancies and deliveries.

If problems arise, the nurse-midwives said, patients immediately are referred to a physician. Under standards set by the American College of Nurse-Midwives, nurse-midwives are required to have backup physicians for consultation and referral.

"We give each client a complete physical and do a family history. If we pick up something wrong, we send them to a physician," said Johansen, who emphasized that women are continually monitored during their pregnancies for problems such as high blood pressure or diabetes.

Nurse-midwives say they also discourage the use of medications in pregnancy and labor and urge parents to take their baby to a pediatrician within 24 hours after birth for a routine medical checkup.

But many in the medical profession question whether nurse-midwives, particularly those attending home births, can provide the best medical care possible.

The issue is of particular concern in Virginia, where, except in limited programs, nurse-midwives have not won the privilege to deliver patients at hospitals.

Family Birth Associates' Daniel, like her colleagues, said nurse-midwives are trained to detect possible complications early enough in labor that a patient can be transferred to a hospital in time for treatment. The transfer rate at Family Birth Associates is about 18 percent, according to Daniel's associate Beveridge, while it is about 15 percent at Annandale Midwifery, according to Moffitt.

Nationally, the hospital transfer rate for home births is about 20 percent, according to Mort Lebow, a spokesman for the American College of Obstetricians and Gynecologists.

Lebow said the college, though it views nurse-midwives as valuable members of the medical team, opposes home births as too risky, a view shared by many in the medical field.

"In 1982, there is no possible medical or personal justification for home delivery in terms of the risks involved . . . ," said Dr. Allan B. Weingold, chairman of the Department of Obstetrics and Gynecology at George Washington University Medical Center. "There are two drawbacks at home. In any labor, in any patient, problems can happen. The time involved in getting to the hospital can be critical for both the mother and the baby. . . .

"And being at home you don't have other professionals for consultation. If you're a midwife delivering in the hospital setting and you have problems, you can call someone in."

Weingold said he is not opposed to nurse-midwife care in general, however, and noted that some nurse-midwives are allowed to deliver patients at the hospital.

"Nurse-midwives have a role to play in the delivery of obstetrical care in this country," Weingold said. "I don't think it will be a major role in the foreseeable future as it is in some European countries because of the way our system has traditionally been organized. But given the proper setting, working as part of a team with physicians in a hospital setting, they have performed admirably."

Overall, physicians who work with nurse-midwives in Northern Virginia say the midwives provide excellent medical care.

"I feel the present certified nurse-midwives have had such excellent training and practical experience," said Dr. Ludovic DeVocht, one of several backup obstetrician-gynecologists for both midwifery practices. "They're definitely qualified to deliver babies and conduct prenatal care. They're capable of seeing problems that could develop and they could do something to avoid or correct those problems in time."

Many nurse-midwives say they would like to offer their patients the option of a hospital birth. Tom, of the American College of Nurse-Midwives, estimates that most nurse-midwives with hospital privileges deliver in hospitals.

But winning hospital privileges, nurse-midwives say, has been an uphill battle.

"It's definitely a matter of conquering prejudices and fears to get in," said Daniel of Family Birth. "They're afraid if they let one in, everyone is going to get in. . . . But we want to be able to offer alternatives to women. Some women who feel much more secure in a hospital setting still want a midwife, and right now that option is not available in Northern Virginia ."

Some nurse-midwives say there may be concern by physicians that midwives could threaten their livelihood in a field already facing an oversupply of physicians.

"We are an economic and political threat, I suppose," said Moffitt.

Midwives' fees, covered by most major insurance companies, generally are much lower than those of physician-attended hospital births. Annandale Midwifery charges $750, and Family Birth, $700, for prenatal care, delivery and postpartum care. In contrast, the hospital bill and physicians' fee for the same services can run more than $2,000 locally, by most estimates.

Deborah Bash, a certified nurse-midwife who works with an obstetrical practice in Alexandria, hopes to get privileges at Alexandria Hospital this fall. "You can have alternative settings in a hospital that simulate home," she said, "and still have the availability of emergency equipment."

An unresolved issue in the question of hospital privileges is that of physician supervision. Many hospitals, even those that have granted nurse-midwives privileges, Tom said, require that a physician be present or nearby for midwife-assisted deliveries.

But nurse-midwives are confident the issue will be resolved in their favor.

"The change will come from the consumers. They'll bring it about," said Annandale Midwifery's Johansen. "Twenty-five years ago, husbands weren't allowed in the delivery room. Consumers changed that. It used to be that no siblings were allowed to visit, but consumers changed that. It used to be that, in a Caesarean birth, the father couldn't be there. But the consumers changed that, too."