|Originally posted by eilonwy
First of all, most of what OBs do is, in fact, based on evidence. Just because it's evidence that you don't like doesn't mean it doesn't exist. Secondly, if you can't tell for a fact that a doctor caused X, Y, and Z and you don't know exactly what the consequences of X, Y, and Z are, how can you assume that the doctor was at fault?
I have to strongly disagree with the idea that what most OBs do is based on evidence. There is a great lack of scientific evidence available about pregnant and laboring women because of the numerous ethical problems that exist with doing a double-blind controlled study with pregnant women and their babies. Most Obstetrical practice, whether carried out by doctors or midwives, is instead based on habits passed down through the oral tradition and personal experience. The problem with this is that many severe complications occur at a rate of one in a thousand or one in ten thousand, so an OB can honestly say, "Well, I've used cytotec many times and never seen a uterine rupture, so I believe it is safe." If that same drug takes maternal mortality from a rate of 3 per 100,000 to 6 per 100,000, effectively doubling it, or if cesareans kill four times as many moms as vaginal births, most OBs will never notice because their own experience will never involve those kinds of numbers. I can give you example after example of OBs continuing to practice procedures which have specifically been proven in study after study to be ineffective, untrustworthy or harmful, from early cord clamping to withholding food and drink during labor to episiotomy (still practiced in more than 60% of births attended by private physicians) to third-trimester ultrasound for weight estimation to induction at less than 42 weeks for a healthy postdates pregnancy. Happily, many other out-of-date procedures, like shaving the pubic hair before birth (thought to prevent infection, actually made it worse) have fallen by the wayside, but change comes very, very slow in the medical community, unless inspired by litigation.
Litigation and other pressures have led to something more insidious than lack of evidence-based practice in my opinion. Many women are being over-aggressively treated for complications that arise in late pregnancy and during labor, resulting in live babies and mothers, but at the cost of additional maternal recovery time, physical trauma to mom and baby, and increased chances of separation. To get to the bottom of what I mean, I will show another example. If a woman is diagnosed with breast cancer, the best thing to do to maximize her chances of remission would be a double mastectomy, with possible removal of lymph nodes, aggressive chemotherapy and radiation, and some kind of continuing drug therapy. However, cancer specialists, using evidence, have come up with a number of other options and can present women with other choices, like perhaps a lumpectomy + radiation and no other treatment. Obviously the second choice, while marginally less successful than more radical treatment, has significant benefits in its lesser trauma and recovery time. A woman with breast cancer is given a whole spectrum of treatment options and is given evidence about the likely benefit of each.
Many pregnant women are being given the birth equivalent of a double mastectomy. If a baby is "too big," an induction or cesarean is ordered (sometimes by a court of law, as we have seen recently). Women who are post-dates are being told they will be "allowed" to go to a certain date. Women who have strep B are told that if they don't accept antibiotics in labor, their babies can be ordered to undergo spinal taps, NICU stays and their own antibiotic courses. Women are often not allowed to choose less aggressive interventions -- when they decline the advice of their Obstetricians and Pediatricians in the birth setting, they are often threatened with court orders.
Homebirth and hospital-based midwives are often guilty of their own practices which are not backed up by evidence. I love Spiritual Midwifery, but cringe when I read some of the things that they do in that book. More common are midwives who put their clients through an exhaustive regimen of supplements and teas and exercises, adding expense and bother to a healthy pregnancy that didn't really need the extra support. Midwives can be too slow to intervene in ways that might prove dangerous as well.
I think that some interventions are absolutely necessary -- some because of problems caused by previous decisions, others which would have been necessary regardless of birth setting. I attended a mom in labor as a doula last year who had a very necessary vacuum extraction, but her 26-hour labor would have been greatly minimized by better care, perhaps eliminating the need for a surgical birth. The thing about interventions, though, is that the community seems to want to take the evidence about when an intervention is warranted, and then write a protocol that is much, much more conservative. The OP gave an example of premature rupture of membranes -- the WHO recommends induction after 48 hours, the ACOG, 24, and most hospitals in my area, 6-12. There is a pretty huge range amongst those numbers. The ACOG has recommended that testing begin to determine placental health and fetal well-being after 42 weeks in a post-date pregnancy, but many doctors begin such testing immediately after 40 weeks, and induce at 41.
One thing that I have come to believe about birth is that if a practitioner has a tool, he or she will use it. In the homebirth practice I work in, we do not have easy access to ultrasound, so it is not a tool we use routinely. My favorite group of hospital-based midwives can't perform cesareans, vacuum extractions or use forceps, and so when they choose to use those tools, they must turn over care to an OB or resident. Consequently, they don't use those options unless they really, really have to. But the OBs, who know that they are likely to produce a relatively healthy baby if they order an immediate cesarean when there is meconium or a deceleration, vs. entering into the unknown by allowing a labor to continue, will often strongly advise a c-birth. There is huge pressure on them to make those recommendations, and I don't blame them, but I also would not choose them for my own care unless my health mandated it.
You are right, though, about the uncertainty of the impact of individual interventions in labor. Did the morphine given in labor cause lingering fetal distress or was it the exhaustion? Was the induction the cause of the meconium or the post-date baby? Did the epidural make it impossible to push out the baby or was it the weak contractions? Hard to know. What the evidence points at, though, is that low-intervention practitioners, like hospital and home-based midwives, achieve simliar if not superior results with matched populations to those achieved by OBs, with fewer interventions. If it is possible to intervene less and still and achieve healthy mom and baby, why not intervene less?