Friday, May 19, 2006

The need for ancient midwives

My previous post (Were ancient midwives the obstetricians of their time?) was inspired by an article in Scientific American on the Evolution of Human Birth. This article appeared in a special edition of Sci Am devoted to Human Evolution (2003). The authors of the article, Karen Rosenberg and Wenda Trevathan, explained their scientific work on the subject. Rosenberg is a paleoanthropologist and Trevathan is a bioanthropologist and is also trained as a midwife!

I cannot link to the article because it requires payment, but I can quote some interesting, relevant passages:

"only recently have anthropologists begun to realize that the complex twists and turns that human babies make as they travel through the birth canal have troubled humans and their ancestors for at least 100,000 years. Fossil clues also indicate that anatomy, not just our social nature, has led human mothers—in contrast to our closest primate relatives and almost all other mammals—to ask for help during childbirth. Indeed, this practice of seeking assistance may have been in place when the earliest members of our genus, Homo, emerged and may possibly date back to five million years ago, when our ancestors first began to walk upright on a regular basis."

They go on to describe the differences between humans and their closest evolutionary relatives, the monkeys. Monkey babies are born facing forward, and actually assist in their own birth by pulling themselves out and up once their arms are free.

Rosenberg and Trevathan assert:

"If human babies were also born face forward, their mothers would have a much easier time. Instead the evolutionary modifications of the human pelvis that enabled hominids to walk upright necessitate that most infants exit the birth canal with the back of their heads against the pubic bones, facing in the opposite direction as the mother ... For this reason, it is difficult for the laboring human mother—whether squatting, sitting, or lying on her back—to reach down and guide the baby as it emerges. This configuration also greatly inhibits the mother’s ability to clear a breathing passage for the infant, to remove the umbilical cord from around its neck or even to lift the baby up to her breast. If she tries to accelerate the delivery by grabbing the baby and guiding it from the birth canal, she risks bending its back awkwardly against the natural curve of its spine. Pulling on a newborn at this angle risks injury to its spinal cord, nerves and muscles."

Assisted childbirth has spread to all cultures:

"Of course, our ancestors and even women today can and do give birth alone successfully... Today virtually all women in all societies seek assistance at delivery... So, though rare exceptions do exist, assisted birth comes close to being a universal custom in human cultures.

Knowing this—and believing that this practice is driven by the difficulty and risk that accompany human birth—we began to think that midwifery is not unique to contemporary humans but instead has its roots deep in our ancestry. Our analysis of the birth process throughout human evolution has led us to suggest that the practice of midwifery might have appeared as early as five million years ago, when bipedalism constricted the size and shape of the pelvis and birth canal."

So, although, midwives provided important psychological support, they also provided an evolutionary advantage. Women who had assistance in childbirth were more likely to survive and have infants who were more likely to survive.

"The triple challenge of big-brained infants, a pelvis designed for walking upright, and a rotational delivery in which the baby emerges facing backward is not merely a contemporary circumstance. For this reason, we suggest that natural selection long ago favored the behavior of seeking assistance during birth because such help compensated for these difficulties."

I wonder if the advantages persisted to the third stage of labor as well. Jamie asked me a question about active management of the third stage (delivery of the placenta) and in thinking about it, I realized that obstetricians almost always assist the third stage by clamping the cord, and applying very gentle traction to it. Postpartum hemorrhage has always been a major cause of maternal death. It is not difficult to imagine that assistants who shepherded delivery of the placenta and then manually massaged the uterus to encourage it to contract, dramatically improved the chances of survival of the women they tended.

This is the genesis of my question about ancient midwives being the obstetricians of their time. According to Rosenberg and Trevathan, technical assistance at delivery (not just psychological support) gave the midwives' "patients" a tremendous survival advantage. So from the beginning of midwifery, possibly millions of years in the past, the assumption was not that birth is simple and only require support, but the assumption was that birth is inherently complicated, that neonatal and maternal death are all too common, and that a trained assistant is needed to increase the chance of neonatal and maternal survival.

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8 Old Comments:

I know another antro who is also a CPM , went to Mexico and studied the women who birth alone. Wrote a paper on it several years ago.
in my own experience seeking help had to do with what and who made me feel safest. 2 hospital births that were such a shock how badly people treat you- some of it is because you are a complete stranger, pressure of understaffing and because it is common place it is just a JOB to these folks and some have alot of attitude now if I am in Walmart that is one thing but when I was vulnerable this felt dangerous not safe, nothing done to me at the hospital felt safe !!!!
the 2 home births I had after the hospital births were wonderful- and I caught my own babies- yes I had a midwife there to support me and to check on baby's welfare- and I got treated with respect- I did what I wanted to do, sat where I wanted to sit, ate what I wanted to eat, drank when I wanted to drink, went to the bathroom when I needed to- took a bath, a shower, rested - stood, sat, squatted, kneeled- and caught my own babies - your hands can reach and I could feel for cord and more than that I could also think what I needed to do- how I needed to move it was simple just like adjusting yourself because your underwear are pinching or you are sitting on something funny- but I know I was not able to even think about myself in this way at the hospital - I was told what to do and I was in the mode of alertness you get when you are trying to be sure nothing bad happens to you right on the edge of fighting or running- I understand why many women end up on meds because this is a lot of time to be changing on the inside and forced to lay down on the outside and interact with complete strangers who are acting in all sorts of ways- some kind but also fearful and angry and rough power tripping - you know like when a clerk at Walmart is having a hard time- PMS or fight with partner or boss being an ass- you know in an instant by expression - you have limited contact with that person- imagine being trapped in a room with someone like that for 8 hrs. someone you can't make inroads to who is bossing you around and not everything she does or tells you to do feels right or good but you suck it up and do your best- and despite it all first hospital birth I hemorrhaged in the recovery room where I was left alone- because the place was busy and it was shift change- 500 cc in the recovery room with no one around to help laying on top of a skinny table I would have never though was safe in my life nor ever would have tried to get on it before or after having a baby. the second hospital birth I did not want to go - I even though about renting a motor home and sitting in the hospital parking lot alone to have the baby- talked a great deal with the new doc I had and though I had it all worked out- was in the hospital 1/2 hr before the baby was born and there was still time to be mistreated amazing- this guy and who would have guess does/did routine manual removal of the placenta- his hand and arm into you to scoop out the placenta- I was in a ward room after the birth and the 10 of us in there all had the same procedure...
the needs of women haven't changed- what has changed is how disrespected we are

By Anonymous Anonymous, at 10:39 AM  

I believe that the treatment of women does not matter to some of the people keeping this thread going. I do not, I believe that women go to homebirth/un assisted birth when they are treated poorly by a segment of the medical community.
It isn't the woman or childs mental and physical health that matters here. It is IF everyone is still breathing at the end of it. Mortality and numbers. Mortality and numbers. That is where the focus lays.
-primary c/s then gosh darn it, should have gone to dinner and a movie homebirth after cesarean mom.
*won't hold my breath that this will be published....

By Anonymous Anonymous, at 2:50 PM  

I asked about third-stage labor because the Cochrane reviewers support active management and I'm guessing that most of us in the homebirth community prefer expectant management. I certainly want to be evidence-based in my thinking, but I would so much rather snuggle and nurse a brand-new baby than get a shot of methergine, puke, and then snuggle and nurse my slightly less brand-new baby.

In your response to me, Amy, you said you rarely saw a need for oxytocics (do you mind that I'm quoting here from a private email? I don't mean to step on your toes), but that seems to be the approach recommended by the Cochrane guys. Curious about the thinking of those in the field.

I am grateful there was methergine to stop my PPH (in the hospital), but does it really need to be used routinely?

I was just doublechecking the links and noticed that one Cochrane review says domiciliary care may be a different kettle of fish. But both of my home-born guys are sitting in my lap, complaining that this is enough time in front of the 'puter on a spring afternoon. Back later.

By Blogger Jamie, at 3:25 PM  

Jamie:

"In your response to me, Amy, you said you rarely saw a need for oxytocics (do you mind that I'm quoting here from a private email? I don't mean to step on your toes), but that seems to be the approach recommended by the Cochrane guys. Curious about the thinking of those in the field."

It's fine to quote from the e-mail. I have not yet had a chance to look at the data on active management of the 3rd stage, but I can't recall ever giving methergine for anything other than a postpartum hemorrhage.

By Blogger Amy Tuteur, MD, at 4:06 PM  

I hope this reminder is helpful -- but in case of pph, there was pit and methergine at my mw attended hb and pit and methergine at my unassisted birth. It's certainly standard of care, I believe, for hb mw's to have both these on hand. It's probably not part of the unassisted birth standard of care; I think most UCers go without, mainly from a desire to rely on other methods to handle PPH or being alienated from a way to get them.

By Anonymous Anonymous, at 5:18 PM  

I hope this reminder is helpful -- but in case of pph, there was pit and methergine at my mw attended hb and pit and methergine at my unassisted birth.

I am sure you were trying to reassure us that women who are attempting unassisted birth are prepared for everything... I'm not impressed though. Unassisted birth might be fine, but unassisted birth with self-administered oxytocics and no clinical evaluation of blood loss, volume replacement, shock, and vital signs is downright scarier than the worst midwife on the scene.

By Anonymous Anonymous, at 11:52 PM  

This isn't a story about "ancient" midwives, but about more recent history. I also wanted to share this because the subject of birth in the African American community has come up a few times here as well.

http://www.timesargus.com/apps/pbcs.dll/article?AID=/20060519/NEWS/605190307/1011/EDUCATION05

Danielle

By Blogger Mama Liberty, at 11:48 AM  

Danielle:

Thanks for the link. I learned something new from the article.

By Blogger Amy Tuteur, MD, at 5:28 PM