Wednesday, October 04, 2006

"Nothing else in medicine has saved lives on the scale that obstetrics has"

Dr. Atul Gawande is probably the best writer in medicine today. He takes a fascinating look at childbirth in this week's issue of The New Yorker. The entire article is terrific, recounting the history of modern obstetrics and much of what we have discussed on this blog for the past several months. The most important quote from the article is as follows:
The Apgar score, as it became known universally, allowed nurses to rate the condition of babies at birth on a scale from zero to ten. An infant got two points if it was pink all over, two for crying, two for taking good, vigorous breaths, two for moving all four limbs, and two if its heart rate was over a hundred. Ten points meant a child born in perfect condition. Four points or less meant a blue, limp baby.

The score was published in 1953, and it transformed child delivery. It turned an intangible and impressionistic clinical concept-the condition of a newly born baby-into a number that people could collect and compare. Using it required observation and documentation of the true condition of every baby. Moreover, even if only because doctors are competitive, it drove them to want to produce better scores-and therefore better outcomes-for the newborns they delivered.

Around the world, virtually every child born in a hospital had an Apgar score recorded at one minute after birth and at five minutes after birth. It quickly became clear that a baby with a terrible Apgar score at one minute could often be resuscitated-with measures like oxygen and warming-to an excellent score at five minutes. Spinal and then epidural anesthesia were found to produce babies with better scores than general anesthesia. Neonatal intensive-care units sprang into existence. Prenatal ultrasound came into use to detect problems for deliveries in advance. Fetal heart monitors became standard. Over the years, hundreds of adjustments in care were made, resulting in what's sometimes called "the obstetrics package." And that package has produced dramatic results. In the United States today, a full-term baby dies in just one out of five hundred childbirths, and a mother dies in one in ten thousand. If the statistics of 1940 had persisted, fifteen thousand mothers would have died last year (instead of fewer than five hundred)-and a hundred and twenty thousand newborns (instead of one-sixth that number).

There's a paradox here. Ask most research physicians how a profession can advance, and they will talk about the model of "evidence-based medicine"-the idea that nothing ought to be introduced into practice unless it has been properly tested and proved effective by research centers, preferably through a double-blind, randomized controlled trial. But, in a 1978 ranking of medical specialties according to their use of hard evidence from randomized clinical trials, obstetrics came in last. Obstetricians did few randomized trials, and when they did they ignored the results. Careful studies have found that fetal heart monitors provide no added benefit over having nurses simply listen to the baby's heart rate hourly. In fact, their use seems to increase unnecessary Cesarean sections, because slight abnormalities in the tracings make everyone nervous about waiting for vaginal delivery. Nonetheless, they are used in nearly all hospital deliveries. Forceps have virtually disappeared from the delivery wards, even though several studies have compared forceps delivery to Cesarean section and found no advantage for Cesarean section. (A few found that mothers actually did better with forceps.)

Doctors in other fields have always looked down their masked noses on their obstetrical colleagues. Obstetricians used to have trouble attracting the top medical students to their specialty, and there seemed little science or sophistication to what they did. Yet almost nothing else in medicine has saved lives on the scale that obstetrics has
. On obstetricians and interventions:
In obstetrics, meanwhile, if a strategy seemed worth trying doctors did not wait for research trials to tell them if it was all right. They just went ahead and tried it, then looked to see if results improved. Obstetrics went about improving the same way Toyota and General Electric did: on the fly, but always paying attention to the results and trying to better them. And it worked. Whether all the adjustments and innovations of the obstetrics package are necessary and beneficial may remain unclear-routine fetal heart monitoring is still controversial, for example. But the package as a whole has made child delivery demonstrably safer and safer, and it has done so despite the increasing age, obesity, and consequent health problems of pregnant mothers.

The Apgar score changed everything. It was practical and easy to calculate, and it gave clinicians at the bedside immediate information on how they were doing. In the rest of medicine, we measure dozens of specific things: blood counts, electrolyte levels, heart rates, viral titers. But we have no measure that puts them together to grade how the patient as a whole is faring. It's like knowing, during a basketball game, how many blocked shots and assists and free throws you have had, but not whether you are actually winning. We have only an impression of how we're performing-and sometimes not even that. At the end of an operation, have I given my patient a one-in-fifty chance of death, or a one-in-five-hundred chance? I don't know. I have no feel for the difference along the way. "How did the surgery go?" the patient's family will ask me. "Fine," I can only say.

The Apgar effect wasn't just a matter of giving clinicians a quick objective read of how they had done. The score also changed the choices they made about how to do better. When chiefs of obstetrics services began poring over the Apgar results of their doctors and midwives, they started to think like a bread-factory manager taking stock of how many loaves the bakers burned. They both want solutions that will lift the results of every employee, from the novice to the most experienced. That means sometimes choosing reliability over the possibility of occasional perfection.
On patient choice C-sections:
A measure of how safe Cesareans have become is that there is ferocious but genuine debate about whether a mother in the thirty-ninth week of pregnancy with no special risks should be offered a Cesarean delivery as an alternative to waiting for labor. The idea seems the worst kind of hubris. How could a Cesarean delivery be considered without even trying a natural one? Surgeons don't suggest that healthy people should get their appendixes taken out or that artificial hips might be stronger than the standard-issue ones. Our complication rates for even simple procedures remain distressingly high. Yet in the next decade or so the industrial revolution in obstetrics could make Cesarean delivery consistently safer than the birth process that evolution gave us.

Currently, one out of five hundred babies who are healthy and kicking at thirty-nine weeks dies before or during childbirth-a historically low rate, but obstetricians have reason to believe that scheduled C-sections could avert at least some of these deaths. Many argue that the results for mothers are safe, too. Scheduled C-sections are certainly far less risky than emergency C-sections-procedures done quickly, in dire circumstances, for mothers and babies already in distress. One recent American study has raised concerns about the safety of scheduled C-sections, but two studies, one in Britain and one in Israel, actually found scheduled C-sections to have lower maternal mortality than vaginal delivery. Mothers who undergo planned C-sections may also (though this remains largely speculation) have fewer problems later in life with incontinence and uterine prolapse.
This article is an excellent history of how obstetrics got to be where it is today. It also debunks the central myth of the homebirth movement, that childbirth is inherently safe because it is natural.

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