As the father of two healthy adult children who were not born in hospitals, as well as being married to a certified nurse midwife (CNM), I take great interest in childbirth, especially its evidence-based aspects. Both of my children were born in out-of-hospital birth centers, where I was the only physician present, and was in no way there in a physician capacity. Both were delivered by CNMs. I always marvel at how pleasant the experience was relative to the eight deliveries I performed as a medical student in an academic hospital in the 1980s.
Two recent studies provide a number of teachable moments concerning evidence-based care. Both studies asked roughly the same question, looking at the risk of perinatal mortality for planned in-hospital vs. out-of-hospital births. One study from Ontario, Canada found no differences in neonatal mortality for planned out-of-hospital births by midwives compared to planned in-hospital births . But another study from Oregon found that there was a higher risk of neonatal mortality in planned out-of-hospital births (3.9 deaths compared to 1.8 deaths per 1000 deliveries) . This study also found a much higher rate of cesarean section (C-section) for in-hospital births (28.1% versus 6.2%). Caesarian sections are associated with a variety of short and longer term patient complications.
What are the teachable moments? Certainly one is that out-of-hospital birth is very safe, especially in a healthcare system when care among midwives and physicians is highly coordinated, as occurs in Canada and most other developed countries. That is not the case in the United States, and it is likely that some complications in Oregon were a result of that lack of coordination. But even in the United States, at least in Oregon, out-of-hospital birth is relatively safe.
Another teachable moment concerns relative versus absolute risk. When stated as a relative risk ratio, the difference in mortality in Oregon was 2.2-fold higher. But neonatal mortality is an extremely rare event. As such, the absolute risk difference between in-hospital and out-of-hospital birth was only 2.1 deaths per 1000 deliveries. This was accompanied by a relative risk ratio for C-section that was 4.5-fold higher and which also had a substantially higher absolute risk difference of 21.9% of all deliveries.
An additional teachable moment concerns some important issues around data. This study was made possible because several years ago, the state of Oregon added a question to birth certificates that asked all women who had an in-hospital delivery, “Did you go into labor planning to deliver at home or at a freestanding birthing center?” This enabled the researchers to determine planned vs. unplanned out-of-hospital births and thus made this study possible. Data does not magically just appear; we have to determine what we want to collect, make plans to collect it, and determine its completeness and validity.
These studies also raise the question of whether the difference in neonatal mortality in Oregon could be ameliorated by better care coordination. The Oregon study also raises the question of whether moving deliveries from hospitals to other settings would reduce the C-section rate. Hopefully these and other questions will be answerable in the future. I certainly hope it may lead to more families being able to experience the pleasant deliveries I was able to have with my children.
1. Hutton, EK, Cappelletti, A, et al. (2015). Outcomes associated with planned place of birth among women with low-risk pregnancies. Canadian Medical Association Journal. Epub ahead of print.
2. Snowden, JM, Tilden, EL, et al. (2015). Planned out-of-hospital birth and birth outcomes. New England Journal of Medicine. 373: 2642-2653.