Wednesday, June 14, 2006

How birth is "supposed" to be

You often hear homebirth advocates say things like, "Women were having babies long before there were doctors. If birth were inherently dangerous, we wouldn't be here". They make the mistake of assuming that since nature "designed" it, birth must have a successful outcome almost all the time.

The process that we observe today is the product of millions of years of evolution. The driving force behind evolution is NOT perfection, it is survival of more offspring of the fittest. That's it. It does not matter how many babies or mothers die in the process of birth, the population will grow as long as the GROUP averages 2.1 children/woman.

The reality is that human reproduction has a high level of "wastage". Even though every ovum is "designed" to be fertilized and develop into a baby, every woman is born with millions of ova she will never use. Even though every sperm is "designed" to fertilize an egg, every man produces billions of sperm that will never do so.

When conception occurs, many newly fertilized eggs fail to divide. Of the ones that divide, many fail to implant in the uterus. Of the ones that implant, many are washed out with the next period (chemical pregnancy). Of the ones that are not washed out (probably less than 50% of the original fertilized eggs) more than one fifth of those will miscarry in the next 3 months. I could go on and on, but I think you get the idea.

Fetal death and neonatal death are natural and expected consequences of pregnancy. This is born out by the appallingly high intrapartum death rates before contemporary obstetrics and or in places where contemporary obstetrics is not practiced.So fetal and neonatal death is fundamental to the process of human birth.

The process of human birth itself represents a compromise between competing evolutionary pressures. On the one hand, a more neurologically mature newborn is more likely to survive, so there is an advantage for a baby to be born more with a bigger head so it will be neurologically more mature. On the other hand, there is a limit to the size of the woman's pelvis. That's because a larger pelvis renders walking more difficult and if the pelvis is large enough, walking upright is impossible. Therefore, there is tremendous evolutionary pressure to increase the size of the neonatal head and equally large evolutionary pressure to limit the size of the maternal pelvis.

I'm sure you can see where this is going:There is naturally and inevitably a significant amount of incompatibility between the size of the baby's head and the size of the mother's pelvis. This is built into the system. In other words, a significant amount of maternal and fetal death is built into the system and is unavoidable. This doesn't even begin to take into account all sorts of other complications like breech or pre-eclampsia or premature labor. Those add significantly to the death rate.You can imagine that starting from the premise that neonatal and maternal deaths are inevitable is going to lead to different conclusions than the erroneous assumption that childbirth is inherently safe.

The worship of the "natural" is based on this false premise. Birth is not "designed" to occur perfectly every time, or even most of the time. It is yet another process that is subject to the brutal competition of evolution.

See original comments here.

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39 Old Comments:

what a surprise
lets look at kinds of elements in health that cause a head- to not fit---
If women in their childhood have rickets- as they had in our past from lack of sunlight and poor nutrition then contracted pelvises or oddly shaped pelvises develop . are rickets now the United States the cause of head-to-pelvis disproportion?

show me how to put on a turtle neck sweater without moving it is possible but alot harder. this would represent the movement of the baby out of the uterus- add to that a firm but not rigid structure - pelvis with soft parts and baby's head with floating fontanels -- movement helps a baby move and fold into position helps to find an angle it can descend through -- why do you think baby's cribs have to have bars very narrowly spaced? because baby's will inevitably try to push it's head through the bars and then get stuck - this is a left over reflex/ dare we say instinct- it is what helps a baby be an active participant in birth-
now I say to you sedate a baby how much movement and crawling do you see?
no matter if you think that epidurals are safe and if they have figured out how to increase contractions- pit drips to go with epidurals - you have sedated the baby - enough to see a heart rate change- enough to see an O2 change on pulse oximeter readings.
what do farmers and people who are involved in animal husbandry know- mess much with a birthing animal and you are going to have problems at birth. Would they yell at a birthing animal, give it meds to stop the pain of birth, pick the place and position an animal will take up in order to give birth- keep bright lights on , expect the animal to perform tricks they have been trained to do during birth? if we can see that many of these things can interfere with an animal why do we think that it doesn't do anything to us?

By Anonymous Anonymous, at 9:16 AM  

I agree with every word you wrote, Amy. I mean, duh, of course, all that is self-evident. Only you and a few posters have argued for un-assisted birth. I argue that you’re confusing yourself even now. One clarification needed. What did you mean by The worship of the "natural" is based on this false premise . How are you now defining natural? Is it YOUR definition, or what you perceive to be midwifery’s definition? And if so, how did you arrive at that conclusion? Please answer these questions specifically.

By Anonymous maribeth, CNM, at 9:19 AM  

Maribeth:

"How are you now defining natural?"

For this purpose, natural means birth as it occured in nature, before the advent of modern obstetrics.

By Blogger Amy Tuteur, MD, at 9:24 AM  

It has nothing to do with midwifery then.... so what's the point?

By Anonymous maribeth, CNM, at 9:40 AM  

Maribeth:

"It has nothing to do with midwifery then.... so what's the point?"

That IS the point. Midwives do not support and practice "natural" childbirth. They have arbitrarily re-defined "natural" to include what they like and exclude what they don't.

Therefore, a campaign for "natural" childbirth is nothing of the sort. It is a campaign for "midwife approved" childbirth.

By Blogger Amy Tuteur, MD, at 9:45 AM  

Okay I disagree with the animal analogy in the first comment because we are bipeds and have a different pelvic structure.

But you simply cannot compare the modern population with the olden days. We have birth control, we have (a lot more) self-determination not have 15 babies in 15 years. We don't have to go harvest or starve. We have clean water. We don't have polio. We don't have corsets. We don't have weird victorian standards that make us stay out of the sun and give us rickets. We have antibiotics and blood tranfusions now.

Amy -- you are worshipping the god of obstetrics. You are guilty of the very thing you are accusing home birth people of. Irrational beliefes not based on reality and refusing to separate out some of the obvious non-medical factors and non-obstetric factors as I stated above in first paragraph. I define antibiotics and blood tranfusions as public health, not obstetrics, so they are medical but available through other means than just by hiring an ob for your primary pregnancy and birth care.

I agree that having access to quality care lowers mortality rates. I disagree that only ob's offer quality care. CPMs with a well-screened mom at home are as safe as the hospital for low risk women. No matter how many times Amy tries to alter the studies that show it, that fact still remains.

(BTW -- not all DEMs are trained well enough and the CPM is the easiest/best way for the public to verify comptency.)

Read what a REAL scientist says.

By Anonymous Anonymous, at 9:46 AM  

>>Therefore, a campaign for "natural" childbirth is nothing of the sort. It is a campaign for "midwife approved" childbirth.<<

You defined the debate, though, so you are the one guilty of that. Notice in the UK they called it normal birth. I prefer undisturbed (or, in reality "as undisturbed as possible").

By Anonymous Anonymous, at 9:48 AM  

You defined the debate, though

That's exactly why it's senseless. A totally hollow argument, as it's no one's understanding but Amy's own. Having nothing to do with homebirth or midwifery or the price of pennies whatsoever...

By Anonymous maribeth, CNM, at 9:54 AM  

I am familiar with Dr. Wagner and have corresponded with him in the past. He knows as well as I do what the studies say, but he misrepresents them all the time.

Dr. Wagner enjoys the cult of the "noble dissident" that is part of homebirth marketing. He is entitled to his opinions, but the fact that very few others agree with him suggests that he is wrong (especially since he has no scientific evidence to stand on).

One of the things I have noticed about Dr. Wagner and others like him is the refusal to go head to head with other doctors who do not agree with him. He writes almost exclusively for non-doctors and while he will appear at hearings or conferences where the other side is represented, these are set pieces in which no opponent is allowed to question him.

The one exception appears to be the case of Cytotec. Then he did have scientific evidence on his side and therefore, doctors changed their practice.

By Blogger Amy Tuteur, MD, at 9:59 AM  

I think that the differences for a biped is they have bigger heads, and they can be more easily freighted out of instinctive behavior

By Anonymous Anonymous, at 10:04 AM  

from amy"The one exception appears to be the case of Cytotec. Then he did have scientific evidence on his side and therefore, doctors changed their practice."

some doctors, some doctors have changed their practice.

By Anonymous Anonymous, at 10:07 AM  

That is funny. I've seen or heard Wagner debate a few people. He's done grand rounds all over the world. He's been published in more than 100 journals. A lot of his writings are very technical. In fact, another of his specialities is assisted fertility.

You crack me up!

Okay, so just because you don't agree with him you go into your auto-pilot of "where's the scientific evidence?" It's so funny!

By Anonymous Anonymous, at 10:11 AM  

It's also got squat to do with science. Amy, stop trying to be so scientific. You're not being scientific in any of your analyses. Science doesn't only mean medical studies.

By Anonymous Anonymous, at 10:12 AM  

Amy, this debate is getting ridiculous. Some of the threads have been interesting and consisted of substantive debate topics. It is frustrating that you abandon topics so quickly and go on to your next rant before the previous discussion has concluded. It is now impossible to keep up with you. The WHO topic was a good example. We left some key questions unanswered... does WHO differentiate in their recommendations between industrialized nations and third world countries? How do they define active management of labor?

You have lost me, Amy. There really are substantive things to discuss, but you don't seem particularly interested. You seem to have a personal agenda and a very large chip on your shoulder. You come across as supremely arrogant and completely uninterested in any ideas that do not fit into your preconceived notions.

I wonder... do you have a daughter or daughter-in-law who has decided to go her own way on this issue and disregard all of your years of wisdom and hard work?

By Blogger Mama Liberty, at 10:46 AM  

Are you jealous of women who birth at home Amy??? Is that why you are the way you are???

By Anonymous Anonymous, at 11:00 AM  

I'm kind of curious, due to the latest rant on evolution pressures to baby's head/Mother's pelvis.... What do you think the C-section rate is going to do to the human species 200 years from now?

By Anonymous Anonymous, at 11:17 AM  

"What do you think the C-section rate is going to do to the human species 200 years from now?"

Evolution does not work that fast.

By Blogger Amy Tuteur, MD, at 11:25 AM  

Mama Liberty:

"Some of the threads have been interesting and consisted of substantive debate topics. It is frustrating that you abandon topics so quickly and go on to your next rant before the previous discussion has concluded."

The topics still exist. They are in the archive. They usually do not fall off the front page until long after people have stopped writing about them. The WHO partogram is a perfect example. Everyone stopped writing about it because no one could come up with any information disputing it.

"There really are substantive things to discuss ..."

These are substantive issues:

What does it tell us about midwives when they petition their government to force women to do without epidurals?

Is "natural" birth a real entity or simply a social construct of natural childbirth advocates?

What is the death rate in human pregnancy and labor without the tools of modern obstetrics?

I know these topics make some people uncomfortable. They require people to examine and question previously unquestioned beliefs, and that's just what should happen in a substantive discussion.

By Blogger Amy Tuteur, MD, at 11:34 AM  

"The topics still exist. They are in the archive. They usually do not fall off the front page until long after people have stopped writing about them. The WHO partogram is a perfect example. Everyone stopped writing about it because no one could come up with any information disputing it."

No, that isn't true. People don't stop talking because they don't have anything to add, but because you just jump into another topic. I (and I believe most blog readers) aren't going to answer topics that are weeks old when there are fresh ones, as who goes back to read all the comments that much later? You dropped the topic and went on to a new one and so did everyone else.

It is very hard to follow your blog and train of thought. Honestly, it begins to seem like you are just grasping for straws, anything that ticks you off rather than going deeper and deeper into the real issues. Why not think about comments that have been made on some of the more interesting topics and make a whole new post about it if you have more to say and have answers to some of the questions posted.

Your answer for everything seems to be that you believe us all to be too stupid to keep up with you or bring up any important ideas. I am just stuck sitting here wondering why you can't go deeper than your initial rants before moving onto another topic.... don't have anymore to add to it?

By Anonymous Anonymous, at 11:44 AM  

I so have to thank you... I've informed a few pregnant moms about this "debate"... all have chosen to discuss homebirth with their midwives.... not that it really matters all that much, midwives in Canada are allowed to deliver in hospital without an almighty OB... So thankful! So thrilled that your inane ramblings and scientific enquiry has pushed some women, gasp they chose midwifery too, to really look at the issue!
THANK YOU!!!
Oh and thanks for the Marsden link... whomever you were. Lovely! Being printed out as I type!
daily laughs, this is my dose of daily laughter!

By Anonymous Thankful Canadian hbac mom, at 11:44 AM  

"The WHO partogram is a perfect example. Everyone stopped writing about it because no one could come up with any information disputing it."

Amy, I quit writing about it because you refused to answer any of my questions/posts about it.

By Anonymous Anonymous, at 12:04 PM  

Amy,

Part of the reason is that things do drop off the page pretty fast. There's not much you can do about it other than change the frequency with which you post new stuff.

I believe you can also reduce the visible post length. I think that if you use the "read more" feature of Blogger you will "fit" more on your front page. Blogger help will tell you how to do this if you are curious.

By Blogger sailorman, at 12:19 PM  

Sailorman,

Thanks. I collect statistics about how many people visit the site at what times. I also track replies to individual posts.

I can watch the traffic tail off when people no longer have anything to add, and watch it pick up again when I write something new.

By Blogger Amy Tuteur, MD, at 12:27 PM  

If there are post topics which have proved to be particularly controversial or which lend themselves to lengthy conversations, you also might want to consider a "best posts" or "favorite posts" or "ongoing debates" list on your sidebar, to save peoiple searching through the archives....

By Blogger sailorman, at 1:08 PM  

>>Amy Tuteur, MD said...
"What do you think the C-section rate is going to do to the human species 200 years from now?"

Evolution does not work that fast.

11:25 AM<<

Another agreement! yay! I love finding common ground.

Yes, 200 years is just a hearbeat on the evolutoinary time line for higher primates.

By Anonymous Anonymous, at 2:08 PM  

Personally, I fully admit not to discussing the WHO suggestions, b/c I'm not a practitioner, and some details do sometimes escape me.

However, based on your previous and subsequent interpretations of other things that I am familiar with, I have to seriously doubt many of your assertions (you=dr.amy) without checking them out myself.

But there's only so much time in the day, and I'm not going to go through the process of learning about that one clinical detail to argue a point to death. (No, that's not a cop out. I admit I don't know enough about that one particlar tangental subject to debate it. That does not apply to the debate-at-large.)

I do not see the pattern of home birthers "giving up" with every debate. What I see is a pattern of you failing to acknowledge valid points from the other side and you diverting many debates into tangents that you think you can disprove. (again you=dr.amy) well, there is, of course, a lot of tangental discussion and debate, admittedly, and now I'm rambling, so I'll shut up.

By Anonymous Anonymous, at 2:16 PM  

And?

By Anonymous Anonymous, at 4:43 PM  

Evolution does not work that fast.

Interesting you say that since it seems we easily shaved a week off average gestation in just ten short years. Evolution (in America) seems to work faster than we think.

By Anonymous clever ID, at 8:21 PM  

amy wrote' The WHO partogram is a perfect example. Everyone stopped writing about it because no one could come up with any information disputing it."

I didn't even bother to answer... I did not think that it was some sort of contest each thing we have to keep answering and answering---
sorry it just wasn't something I wanted to contribute to- I have the WHO recommendations on CD and they are findable on line... there are also some newer growth charts for breast fed babies...

By Anonymous Anonymous, at 10:16 PM  

Amy wrote "What does it tell us about midwives when they petition their government to force women to do without epidurals?"

not exactly the wording that was even discussed- the UK midwives discussed a potential self-pay charge for women who choose an epidural birth- the same as insurance not paying for circumcisions, or breast augmentation, or kidney transplant medications in this country- although the transplant meds are certainly far steeper in cost. They have a packet of studies that they presented trying to prevent an increase in c-sections or other interventions like vacuum extractor assisted births. Do they really have self-interest and power going on- we know that they historically and still carry pain meds even to home births- and at times moms have to buy extra tanks to shore up the supply-- they are saying that they have a huge shortage of midwives and remember they don't use nurses to monitor labors they use midwives -- so instead of having a nurse sitting beside you in labor you have a midwife- she has spent most of her training in the field of pregnancy, birth and postpartum- if they do not speak out who will? obviously the doctors in this country think nothing of adding to a mother's risk they are saying that women are not adequately warned of the risks of the proposed procedures before they accept it ... and they could be right- adding a cost would certainly cause some people to pause and see- and it is not like they would be without any pain meds at all...... or if they needed them the drugs would be paid for--- that is not the same as what you are saying amy-- and we do not live in the UK so we cannot say how they take that advice...

By Anonymous Anonymous, at 10:48 PM  

Sailorman, many congrats, and I was kidding about you leaving. I knew you were absent before these last crazy posts. Sorry for the flippant comment.

Why can't we agree not to split hairs and use words as they are commonly used in modern language - ie, natural childbirth does not mean without stethoscopes, for goodness sakes, but without pain medicine. Normal birth is more debatable, and would make for an interesting thread - NOT started with mean bias please, just inquiry as to everyone's definition of normal birth.

I've slept about 15 hours since sunday morning, so I'm not up to date on posts right now. Four NORMAL births (BC, home and hospital) and two crazy clinic days.

By Anonymous maribeth, CNM, at 7:15 AM  

clever ID said...

Evolution does not work that fast.

Interesting you say that since it seems we easily shaved a week off average gestation in just ten short years. Evolution (in America) seems to work faster than we think.

8:21 PM


That is almost definitely not a result of evolution. Evolutionary changes are based on a selective or adaptive process.

A change of that magnitude, in a time well under the time required for a single generation, is almost definitely not evolution. It is the result of an external factor.

I don't know which one or which combination of factors is responsible. But some random examples might include
-changes in diet
-changes in environmental exposure
-changes in medical care

and so on.


maribeth: I didn't realize you were joking, which is why I was annoyed. Thanks for apologizing (apology accepted)... ;)

By Blogger sailorman, at 10:14 AM  

That is almost definitely not a result of evolution.

I was being facetious. Still, 10 years is a VERY short time to alter American getstational length. Your short list of possibilities asid, remember our superiority?

By Anonymous clever ID, at 10:38 AM  

Clever id:

"Still, 10 years is a VERY short time to alter American gestational length."

There is no specific length of gestation. There is just a probablity curve that is typically centered on 40 weeks and zero days. What we know is that babies born after 37 weeks and before 42 weeks do better than those born earlier or later.

The average gestational age can fall for a variety of reasons including increases in prematurity and decreases in postdates.

The fact that late prematurity has risen as a proportion of premature births may reflect the fact that intensive medical therapy has succeeded in turning pregnancies that would have delivered before 34 weeks into deliveries from 34-36 weeks. If that is what is happening, it is a cause for celebration, not concern.

By Blogger Amy Tuteur, MD, at 11:26 AM  

It would seem simple to me - primarily, the increased induction rate. Next, the increased rate of assisted fertility and multiples. This is skewed evolution if there ever was.

By Anonymous maribeth, CNM, at 12:59 PM  

I must protest strongly, mostly because I spend a lot of time argiung with the ID folks...

Please, please, don't call this "evolution." It's not. Evolution is such an important topic these days that you need to use it right.

First of all, it's not clear there's a reall effect at all.

But even if there is... One easy way in which it's probably not evolution? Well, if it's evolution then this is hereditary (that's how evolution works). it MUST be genetic in nature.

1) Genotype (what's in your genes) leads to changes in phenotype (the "you" based on your genes and modified by your environment);
2) selection acts on phenotypes to improve/deter survival of a certain set of phenotypes;
3) to the degree that those phenotypes are a) selected for, and b) linked to genotypes, they will...
4)...increase/decrease the percentage of a certain genotype in the population.

Here, there's no evidence that the children who were born earlier (if they were) will produce their own children who were born earlier. Nor is there evidence that there are genetic differences. You MUST have that type of evidence, or other proof, to conclude that evolution is the cause.

Otherwise, this is either a) not really a true change, or b) probably a result of environment.

The most obvious explanation would be the fairly large advances we have made in managing and monitoring pregnancy.

By Blogger sailorman, at 1:27 PM  

Yeah, I should have put a "" around evolution when I said it.

I totally agree, well said.

By Anonymous maribeth, CNM, at 1:36 PM  

so several things I have read lately about preterm labor say something similar to this quote. this fits into discussions we had earlier about race this was written in the UK-- and also fits into comments about early birth.
"This is associated with an accelerated rate of maturity in the black fetus and neonate, with correspondingly lower gestation-specific neonatal mortality rates below 38 weeks, and higher at 38 weeks of gestation and beyond. Ethnic differences can explain only a very small proportion of global preterm births. The greatest aetiological factor worldwide is infection, mainly due to malaria and HIV. In developed countries, iatrogenic delivery is responsible for almost half of the births between 28 and 35 weeks; hypertension and pre-eclampsia are the major pathologies. Other factors include multiple pregnancy, intrauterine growth restriction, maternal stress and heavy physical work."

By Anonymous Anonymous, at 1:52 AM  

"iatrogenic delivery is responsible for almost half of the births between 28 and 35 weeks; hypertension and pre-eclampsia are the major pathologies. Other factors include multiple pregnancy, intrauterine growth restriction,"

It sounds like you are quoting this because you don't really understand what it means. It supports my point of view, not yours.

What it says is that many babies are deliberately delivered early to protect them (or their mothers) from death. So the prematurity rate is going up and that causes the death rate to go down (since many of those deliberately delivered early would have died otherwise).

By Blogger Amy Tuteur, MD, at 7:13 AM