The study examined 418 Amish women who delivered 927 babies at a birthing center in Southern Wisconsin, a facility that lacked an operating room.
Over a 17-year period, just 4 percent of babies were born by Cesarean section at the birthing center. In the general U.S. population, by contrast, nearly a third of babies are born by C-section.
Despite the low C-section rate among the Amish women, there were few complications: the rate of newborn deaths was 5.4 deaths per 1,000 deliveries, similar to the general U.S. population's rate of 4.5 deaths per 1,000 deliveries, the researchers said. No mothers in the study died.
One of the biggest contributors to the reduced C-section rate was an increase in the percentage of women who gave birth vaginally after previously having a C-section. In the Amish population, the rate was 95 percent, compared with 8 percent in the U.S. as a whole.
Historically, doctors have had concerns that a vaginal birth after a C-section, a so-called VBAC, would increase the risk of a rupture of the uterus. But in the study, no women experienced this complication.
In 2010, the National Institutes of Health recommended that women with previous C-sections attempt, in subsequent pregnancies, to delivery vaginally first, before resorting to a repeat C-section.
This study's findings suggest that following these guidelines could safely reduce C-sections, said study researcher Dr. Lee Dresang, a professor at the University of Wisconsin Department of Family Medicine.
Another contributor to the low C-section rate among the Amish women was that doctors attempted to turn breech-position (feet-first) babies around from outside the mothers' bodies, to permit vaginal delivery. The method succeeded most of the time, Dresang said. In the United States, 92 percent of women whose babies are in the breech position at the end of pregnancy have a C-section.
Amish women generally give birth at home with an unlicensed birth attendant. As a safer alternative for these women, the LaFarge Medical Clinic in Wisconsin developed a birthing center, staffed by a family doctor and midwife. Women were sent to a hospital 20 minutes away from the clinic if it appeared they needed a C-section or other hospital care, but this occurred rarely.
Although the rate of newborn deaths in the study was slightly higher than that of the general population, this was not unanticipated for the Amish population, Dresang said. This is because few Amish women have prenatal care or undergo genetic testing before birth, he said.
The findings show that such birthing centers can deliver babies "almost as safely as people in hospitals do," said Dr. James Ducey, director of Obstetrics and Maternal Fetal Medicine at Staten Island University Hospital, who was not involved in the study. Of the 19 babies who died in the study, only one died of a condition that could have been prevented in a hospital, Ducey said.
The negative effects for mothers that come from performing thousands more C-sections, including an increase in maternal deaths, may outweigh the benefit of saving one extra life, Ducey said. In 2010, a National Institutes of Health analysis showed that 3.8 maternal deaths occurred for every 100,000 VBACs, whereas 13.4 deaths occurred for every 100,000 repeat C-sections.
It is important to note that Amish women known to have high-risk pregnancies were not allowed to give birth at the clinic; they were instead sent to the hospital. Therefore, the rate of C-sections may have been higher if these women were included.
While the researchers said they do not think the C-section rate in the United States could be brought as low as 4 percent, the lessons from the new study may help move the country toward a lower rate, Dresang said.
The study is published Nov. 12 in the journal Annals of Family Medicine.