I just copied and pasted what she wrote....no credit for this whatsoever. I will say this is one of the most concise, clear breakdowns of this particular debate that I've read in a long time.
Tuesday, June 30, 2009
Cesarean section is NOT the reason the maternal mortality rate has gone down
It has been a while since I posted another OB myth. Today's myth comes to us courtesy of Dr. Amy. Another Amy, Amy Romano, wrote a blog post in which she questions the lack of attention to the maternity care situation in an article written by Dr. Atul Gawande. In her blog post, she says,
Gawande saw a fall over time in perinatal and maternal mortality and attributed it to advances in hospital-based obstetrics. But he knows as well as anyone that correlation is not the same as causation. While a few medical advances — oxytocics and ergot derivatives to control hemorrhages, antibiotics to treat infection, and surfactant to treat respiratory distress in premature infants — have certainly prevented deaths, much of the fall in mortality likely comes from basic improvements in public health and hygiene. By looking through the bifocal lenses of medicine and history, Gawande makes an erroneous assumption that, when it comes to giving birth, more technology is inherently better. What he fails to ask is the very question at the heart of The Cost Conundrum: could we get the same or even better outcomes with fewer risky and costly procedures?Of course, leave it to Dr. Amy to come around and champion the cause of medical technology. In the comments section, she says,
Basic improvements in public health and hygeine occured in the late 19th and early 20th Century. The spectacular drop in maternal mortality (99%) and neonatal mortality (90%) occurred between 1940-1980, long after basic advances in public health.But Dr. Amy makes the same mistake that Amy Romano pointed out Dr. Atul Gawande made, and that most hospital birth advocates make: correlation is not the same as causation.One of the advances most closely associated with the drop in maternal and neonatal mortality is the development and improvement of epidural anesthesia, making Cesarean section far less risky and far more common.
Dr. Amy mentions that the "spectacular drop" in maternal mortality, which occurred between 1940-1980, can be largely attributed to the use of the epidural, and therefore the relative safety of the cesarean section. This is an inherently illogical conclusion, as it assumes that cesarean sections were previously risky due to the method of anesthesia. In fact, the two biggest risks of cesarean section were (and still are) blood loss and infection, neither of which have anything to do with the method of anesthesia.
One of the main causes of blood loss during cesarean section prior to the end of the 19th century was the fact that physicians did not suture the uterus closed, fearing infection from the internal sutures. In 1882, Max Saumlnger, of Leipzig began arguing in favor of uterine sutures, and together with the development of silver wire sutures, physicians began using internal sutures, which necessarily reduced the rate of severe hemorrhage. From the late 1800s to the 1920s, physicians continued to improve the procedure itself, including performing the surgery earlier in labor, before the mother was on the verge of death, and using a transverse incision. (Please view this publication for more on the history of the cesarean section.) The first spinal block was not used until 1943 (ref), so while the epidural certainly contributed to overall improvements in the surgery, advances that directly eliminated or reduced factors that contributed to maternal mortality were already in place.
So what were women dying in or after childbirth dying from? The most feared complications of childbirth pre-1950s were hemorrhage, obstructed labor, and infection.
Hemorrhage
Blood loss is one of the most feared complications in childbirth. It is a reasonable fear! When the placenta separates from the uterus, several minor and major blood vessels are left exposed, and continue to pump blood until the uterus clamps down and closes them off. In some cases, the uterus does not do this adequately, or fast enough, which can result in blood loss, shock, and eventually death for the mother. Prior to the 1930s, there was not much modern medicine could do for blood loss. Midwives had traditionally used herbal remedies, such as ergot, to treat hemorrhage, but it was slow-acting and had serious side effects, including the potential to cause death. In 1909, the hormone oxytocin was discovered, but was not widely available. In 1935, the specific oxytocic agent in ergot was isolated, and preparations were made available. But the real discovery came in 1953, when the biochemist Vincent du Vigneaud discovered a way to create a manufacture-able, synthetic version of oxytocin (now known as pitocin). (ref)
No one can argue that the discovery of oxytocics was a significant step in advancing women's health, but equally significant was the improvement in women's lifestyles and nutrition. A study was done in Maryland which looked at a certain population of women's diets, which diet was considered to be comparable to that of women in the late 19th century, and found that 70% these women were severely anemic, and many had contracted pelvises (more on that in a minute). (ref) According to this publication, anemia in pregnant women reduces a woman’s ability to survive bleeding during and after childbirth, and is associated with 22% of mother's deaths (as of 2006). While oxytocics can slow a postpartum hemorrhage and prevent many immediate deaths, a reduction of severe anemia in pregnant women helps ensure they will survive in the days and weeks following a major hemorrhage. With increased proper nutrition among childbearing women over the years, it's no wonder that the maternal mortality rate has continued to decline. It is interesting to note that severe anemia due to poor nutrition still accounts for a significant portion of maternal deaths today in developing countries and poorer populations.
(It is also worth noting that while postpartum hemorrhage is typically associated with vaginal birth, the average blood loss from a c-section is twice that of an average vaginal birth. (ref) In addition, since 1998, the rate of blood transfusions in the US among all delivering women has increased by 90%. (ref))
Obstructed Labor
Obstructed labor, for various reasons, was a common cause of death previous to the improvements made in the safety of the cesarean section. If a baby was transverse, or stuck in the pelvis, or for whatever reason could not be delivered, it resulted in the mother's death. Prior to the improvements made to the overall safety of the cesarean section, if a woman did not die from the obstructed labor, she would certainly die from any surgical attempt made to save the baby. In that respect, one could argue that cesarean sections are the one of the main reasons for the reduction of maternal deaths due to obstructed labor. However, at the same time as improvements in obstetric care were developing, the number of obstructed labors were decreasing.
Obstructed labor is usually due to three main causes: malpositioned fetus (as in transverse lie), malpresentation (as in brow first), and cephalopelvic disproportion (CPD). One of the main causes of CPD is an inadequate bone or skeletal structure, directly related to poor nutrition. (See this article for a more detailed discussion of nutrition and obstructed labor). In the late 19th century, this often meant rickets. Women and children in urban areas, working in factories where they were largely not exposed to sunlight, and eating poorly, suffered this condition which often resulted in pelvic deformities.
In the book, Women's Bodies: A Social History of Women's Encounter with Health, Ill-Health, and Medicine, the author estimates that in some areas at this time, one out of every four women suffered from some degree of pelvic contraction. The percentage of women with contracted pelvises who died as a result of obstructed labor varied, from 20% of mildly contracted pelvises to almost 50% of severely contracted pelvises. With the total percentage of women presenting with a malpresentation or or malposition averaging around only 4% of total births, the reduction in the number of women with some degree of pelvic contraction, who accounted for perhaps 25% of all births in some areas, would have a particularly important effect on the overall maternal mortality rate.
How was this achieved? By the 1920s, researchers had learned what was causing rickets and other similar bone-deformity diseases, and successfully patented a method of irradiating food, and began a campaign to irradiate commonly eaten foods in an attempt to lower the incidence of rickets. (ref) By the 1940s, Vitamin D-fortified milk was ubiquitous, and the incidence of death of children due to rickets had been reduced to less than 75 cases a year. (ref)
So while the improved safety of c-sections certainly positively impacted the maternal mortality rate among women with malpresentations or malpositions, the largest reduction in maternal morality rate from obstructed labor has quite clearly come from better nutrition and lifestyle, which prevents contracted pelvises in the first place.
Infection
In the early days of hospital birth, another common cause of maternal death was "childbed fever," or puerperal sepsis. Puerperal fever is an infection caused by transmission of bacteria (most often Group A Streptococcus) to a woman, resulting in sepsis, and if untreated, death. Prior to the advent of antibiotics, puerperal fever was one of the leading causes of death among women in hospitals. Puerperal fever was known to kill postpartum women before the advent of hospital birth, but the incidence of it was apparently uncommon. When birth moved into the hospitals, doctors themselves caused outbreaks of the infection by going from patient to patient and performing vaginal exams without gloves, clean clothes, or washing their hands. In some cases, doctors would go from an autopsy to an exam of a pregnant or recently-delivered woman. (Read this article for more discussion on the history of childbed fever.)
In the mid- to late 19th century, several doctors put forth the idea of bacteria transmission as the cause of puerperal fever, but were dismissed. By the turn of the century, the theory of bacteria transmission was widely accepted, but aseptic routine was still not widely practiced. According to the article referenced above, the maternal mortality rate continued to stay the same until the 1930s, the United States continuing to have the worst maternal mortality rate among industrialized nations.
In 1935, a German doctor introduced the use of prontosil, a sulfonamide dye, the precursor to the use of penicillin and modern antibiotics, as a treatment for puerperal fever. It worked remarkably well, and by the end of WWII, penicillin was widely available and used to combat all types of infections, puerperal fever included. The result was that by 1949, the maternal mortality rate in the United States dropped by more than 700%. (ref)
What does all this mean? It means that the time period which Dr. Amy was referring to - the 1940s - might have seen the advent of the epidural, but that was almost certainly not the reason why our maternal mortality rate declined. The 1940s saw a reduction in bone deformity diseases, a reduction in anemia, a reduction in transmission of bacteria, and a successful way to treat bacterial infections. These advances were by and large brought about by cleaner conditions, better health, and better nutrition. The cesarean section has certainly had its place in the preservation of women's lives, but was not the first or the last word in maternal mortality, as proponents would like to argue.
But even if the c-section were the saving grace of modern women, surely we should be seeing an even more dramatic drop in maternal mortality today? Not so. In 2003, the maternal mortality in the United States ROSE to 12.1 deaths per 100,000 live births, to a rate higher than it had ever been since 1976. (see more numbers here.) The United States ranks 41st, continuing to rank last among industrialized nations as we did before all these new advances, for maternal mortality. Women are still dying in or after childbirth! Study after study continue to come out that show the risks of cesarean section relative to vaginal birth, and show the benefit of low-intervention births. It is obvious that the cesarean section, while essential to many women in high-risk situations, is NOT the primary reason maternal mortality rates fell in our country.
And I would like to ask the Dr. Amys and Atul Gawandes of the world what Amy Romano is asking: could we get the same or even better outcomes with fewer risky and costly procedures?
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