Dr. Tracy responds: Lack of randomized, controlled data is a problem
“DOES HOME BIRTH EMPOWER WOMEN, OR IMPERIL THEM AND THEIR BABIES?” ERIN E. TRACY, MD, MPH (AUGUST)
The literature on home birth is flawed and often involves limited outcome measures. There is only one randomized, controlled trial of the practice—and it is very small.1 As for the articles referenced in the letter from the Midwives Alliance of North America, they aren’t necessarily generalizable to the US population. The study by de Jonge and colleagues, for example, involves women in the Netherlands, where home-delivery practices are clearly outlined.
In the Netherlands, home birth requires:
- qualified, well-trained attendants
- strict transfer criteria
- formal collaborative arrangements between providers
- close geographic proximity to local health-care facilities
- strict exclusion criteria (including the presence of meconium).
None of these variables apply to the US population.
In the United States, geographic challenges are real. (The skill of attendants will be discussed a little later.) Many midwives practice with no formal transfer arrangements with specific institutions or providers, and there are no defined, universally accepted criteria for transfer or exclusion from home delivery.
The Johnson and Daviss article is often heralded because this study of 5,418 women resulted in no maternal fatalities. The maternal-fatality rate in this country is 8 in every 100,000 women. 2 The zero mortality rate found by Johnson and Daviss is therefore not surprising. This study was also underpowered to detect any meaningful change in neonatal mortality. One would also hope that women who are deemed to be at low risk of complication would have better outcomes and less need for medical intervention than those who self-select to seek physician care.
CPM training is insufficiently rigorous
In regard to the CPM credential, the presence of a certifying examination doesn’t replace the need for adequate clinical training. Only experience and volume enable providers to learn to recognize obstetric complications and provide appropriate treatment. Examinations are limited in their ability to evaluate providers’ competence in real time, in clinical scenarios. The CPM credential requires only minimal clinical exposure, as spelled out on the Web site of the North American Registry of Midwives:
- As an active participant, you must attend a minimum of 20 births….Functioning in the role of primary midwife under supervision, you must attend a minimum of an additional 20 births:
- A minimum of 10 of the 20 births attended as primary under supervision must be in homes or other out-of-hospital settings; and
- A minimum of three of the 20 births attended as primary under supervision must be with women for whom you have provided primary care during at least four prenatal visits, birth, newborn exam, and one postpartum exam.3
Indeed, the experts on midwifery care, the American College of Nurse-Midwives, recently sent letters to members of Congress objecting to the recognition of the CPM credential, noting, “Accreditation of the certifying body…is not the same as requiring graduation from a formal accredited educational program prior to taking the certification exam.” 4 This letter goes on to rightly note, “As a nation with a well developed health care infrastructure, the US should lead the way in professional standards—not accept a lesser standard for midwifery than any other health care profession.”
Many variables contribute to high cesarean-delivery rate
In regard to Ms. Prowant’s concerns about the rate of cesarean section, I suspect I speak for most obstetricians when I echo her trepidation. As a patient myself, I was happy that I didn’t need a major abdominal surgery for my own deliveries, and I fully support women’s desire to experience natural childbirth without any medical intervention.
One mustn’t forget, however, the many variables that contribute to this country’s cesarean-delivery rate:
- the worsening American obesity epidemic
- the litigious society in which we live
- the increased number of women with multiple gestations
- the advent of elective cesarean section by patient choice.
The increasing age at which women reproduce in this country is also associated with multiple risk factors that increase the risk of fetal intolerance of labor and labor dystocia, including placental insufficiency, diabetes, and hypertension.
That said, obstetricians are committed to addressing variables that are within our control, and ACOG even created a Task Force on the Cesarean Delivery Rate in 1997, which published a monograph outlining the issue in great detail.5
The burden of proof in establishing safety of health-care delivery in the absence of immediate access to potentially life-saving medical or surgical interventions must reside with those who advocate for home birth. While there are some data that demonstrate no increased risk, other data reveal the opposite, as outlined in my article. In the interim, patients should be educated about all of these issues, including the limitations of services in the home setting, the recognized potential for emergent transfer with the potential for adverse outcomes in the process, and the educational level and background of their health-care providers.