April 10, 1997
Women with low-risk pregnancies receive fewer obstetrical interventions when cared for by midwives, compared to women attended by physicians
Low-risk patients who choose nurse midwives for their obstetrical care have fewer Caesarean sections, receive less anesthesia, have a much lower rate of episiotomy and incur less expense, compared to similar women who choose physicians for their care. At the same time, obstetricians, family physicians and nurse midwives all achieve excellent results.
These are the conclusions of a University of Washington study reported in the current issue of the American Journal of Public Health.
“Nurse midwives establish a relationship with their patients that leads to excellent outcomes with less use of medical resources,” said Dr. Roger A. Rosenblatt, UW professor of family medicine and principal investigator on the study. “Pregnancy is the most common reason that women spend time in hospitals, and there are major differences in the way physicians and nurse midwives approach low-risk patients.”
The researchers took a random sample of all the urban practitioners in Washington state who deliver babies in hospitals: nurse midwives, family doctors, and obstetricians. They then took a random sample of those practitioners’ low-risk patients, eventually analyzing 1,322 medical charts for more than 1,000 variables, covering mothers’ and babies’ status prenatally and during labor and birth.
The study found that the patients of certified nurse-midwives were less likely to receive continuous fetal monitoring or to have their labors induced or augmented. They were also less likely to receive epidural anesthesia. Overall, patients of midwives used 12 percent fewer resources than patients of physicians. Rosenblatt noted that midwives account for only 4 percent of deliveries in this country; they deliver the majority of babies in many countries, including Britain.
The Caesarean-section rate for patients of certified nurse midwives was 8.8 percent, compared to 13.6 percent for obstetricians and 15.1 percent for family physicians. “We used an ‘intention-to-treat’ protocol,” explained Rosenblatt. “For example, if the patient of a midwife ended up needing a C-section, the procedure was attributed to the midwife, not to the obstetrician who performed the surgery.”
The study found little difference between the practice patterns of the two groups of physicians. Obstetricians and family physicians seem to be very similar in their approaches to low-risk pregnant women.
“The major limitation of our study was that women chose their own provider, rather than being randomly allocated to different types of care,” Rosenblatt acknowledged. “But in the United States, patient choice is very important. The characteristics of the women as well as the practice style of the provider likely influenced the type of care received. But the study showed that in some patients, it is possible to achieve lower rates of obstetrical intervention by adding midwives to the provider mix.
“This was not a study of quality of care, but of cost and outcome,” said Rosenblatt. “However, we found that labor and delivery are incredibly safe in the state of Washington. There were no neonatal deaths, and the five-minute Apgar scores (a numerical assessment of newborn status five minutes after birth) were very high.
“We hope that this study sparks discussions of less intrusive styles of obstetric care, even among nurse midwives,” he said. “Most of them worked in sophisticated urban hospitals, and half of their patients were given continuous fetal monitoring, even though earlier studies have shown that intermittent monitoring is just as effective.”
The definition of low risk excluded 53 percent of pregnancies. Women were excluded from the study if they had a major medical condition, a previous obstetrical complication, a serious risk factor in the current pregnancy, no obstetrical care in the first trimester, or were under 18 or over 34 years old.
The study was funded by the Agency for Health Care Policy and Research. Co-investigators are Drs. Sharon A. Dobie, L. Gary Hart, Ronald Schneeweiss and Michael J. Pirani of the UW Department of Family Medicine; Dr. Thomas J. Benedetti of the UW Department of Obstetrics and Gynecology; Dr. Edward B. Perrin of the UW Department of Health Services; Dr. Debra Gould of the University of Rochester Department of Family Medicine; and Dr. Tina R. Raine of the Georgetown University Department of Obstetrics and Gynecology.
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