Human Pregnancy Length Controlled By Metabolism Speed, Not Pelvic Shape

Discussion in 'Scientific Studies' started by haidut, Sep 7, 2016.

  1. haidut

    haidut Member

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    Ray has written in several of his articles that human pregnancy is controlled primarily by the amounts of progesterone produced by the mother while pregnant. When the baby reaches a size that the metabolism of the mother and hence the production of progesterone cannot maintain any longer, labor occurs and the baby is born. Given the close relationship between progesterone production and metabolism, one could say that labor occurs when the mother's metabolism can no longer support the baby's development in-utero through the production of enough progesterone. In support of this theory, the clinically used tocolytic (pregnancy prolonging) substances such as vitamin E, magnesium, and some anti-prolactin agents all have progesteronic and/or anti-estrogenic effects. Estrogenic chemicals induce labor (or should I call abortion) almost immediately.
    However, despite this coherent view of the organism and the supporting evidence from clinically useful substances, for the last 40 years the mainstream theory for human gestation is that it is controlled primarily by the size of the mother's birth canal. In other words, when the baby reaches a size that supposedly is just about the size of the birth canal labor occurs to prevent the baby from getting any bigger and thus becoming too big to pass through.
    This latest research seems to corroborate Peat's bioenergetic and pro-progesteronic view - i.e. it is the mother's metabolic intensity and not the size of the birth canal that determines when a baby will be born.

    https://www.sciencedaily.com/releases/2012/08/120827152037.htm
    "...Two traits that set humans apart from other primates -- big brains and the ability to walk upright -- could be at odds when it comes to childbirth. Big brains and the big heads that encase them are hard to push through the human birth canal, but a wider pelvis might compromise bipedal walking. Scientists have long posited that nature's solution to this problem, which is known as the "obstetric dilemma," was to shorten the duration of gestation so that babies are born before their heads get too big. As a result, human babies are relatively helpless and seemingly underdeveloped in terms of motor and cognitive ability compared to other primates."

    "...For mammals in general, including humans, gestation length and offspring size are predicted by mother's body size. Because body size is a good proxy for an animal's metabolic rate and function, Dunsworth started to wonder if metabolism might offer a better explanation for the timing of human birth than the pelvis."

    "..."Under the EGG, babies are born when they're born because mother cannot put any more energy into gestation and fetal growth," Dunsworth explains. "Mom's energy is the primary evolutionary constraint, not the hips." Using metabolic data on pregnant women, the researchers show that women give birth just as they are about to cross into a metabolic danger zone. "There is a limit to the number of calories our bodies can burn each day," says Pontzer. "During pregnancy, women approach that energetic ceiling and give birth right before they reach it. That suggests there is an energetic limit to human gestation length and fetal growth." Those metabolic constraints help explain why human babies are so helpless compared to our primate kin, like chimpanzees. A chimp baby begins crawling at one month, whereas human babies don't crawl until around seven months. But for a human to give birth to a newborn at the same developmental level as chimp, it would take a 16-month gestation. That would place mothers well past their energetic limits. In fact, even one extra month of gestation would cross into the metabolic danger zone, the researchers found."
     
  2. jag2594

    jag2594 Member

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    If babies are born because the mother cannot put any more energy into gestation, then in theory, no one would be born if a mother had more energy to expend. I am skeptical about your references because it gives the impression that it's the quantity rather than quality of gestation that effects brain development. Nine months is a long time before a baby is developed and many things happen in between that can either effect the baby positively or negatively.

    Ray Peat in Nutrition for women stated that large head babies are actually easier to give birth to. The mechanistic proponent of giving birth seems sketchy.
     
  3. OP
    haidut

    haidut Member

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    Well, yes, if the mother could put out an infinite amount of energy to support an evergrowing fetus then nobody would be born ever. But she can't, there is a limit on the metabolism for each person that can be safely reached and maintained. So, labor occurs before that limit is reached. That's what the article is about. So, not sure what's the disconnect you notice...
     
  4. dfspcc20

    dfspcc20 Member

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    With our second child, my wife went to 42 weeks; no signs of labor at that point, except for some of the mucous plug coming out. We were working with a midwife group then, but 42 weeks was their max, so they had to transfer us to an OB/GYN. Had an ultrasound done, got scare tactics about "low amniotic fluid", and she got induced that night. Labor didn't really progress much, and ended up with a C-section. Daughter was born at 10.5 lbs. This was 2.5 years ago. Our daughter has been >95th percentile of height and weight since then, is lean, active and curious, and has always been ahead of the curve in terms of milestones (which is common for full/extra-term pregnancies, from what I understand).

    But I've always wondered why labor never seemed to come for my wife then. Maybe she just had adequate an metabolism/energy level? She wasn't supplementing with progesterone then. We were more WAPF than Peat then, so we weren't eating junk, but weren't really high-sugar then either. Maybe she just would have gone to 43 (or 44, or 45) weeks and labor would have started on its own and been fine. We'll never know.

    For our 1st, my wife went to 1 day shy of 40 weeks before labor started. Our son was born at ~8.5lbs, vaginally, with forceps-assist due to him being posterior. She might have been under more stress, due to working then, so maybe might have had a worse estrogen/progesterone ratio. Again, we'll never know.
     
  5. OP
    haidut

    haidut Member

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    This is quite interesting! Thanks for sharing. Does your wife have any blood tests from both pregnancies? The medical practitioners sometimes to there for pre-term and post-term babies to assess situation and any risks fro upcoming procedures. But yes, unless there is evidence of low amniotic fluid (which can easily be confirmed with ultrasound) it is probably best to let the child come out when she/he wants. I doubt any other environment they will encounter throughout their entire lives will come even close in benefits to the one they enjoy in-utero.
     
  6. dfspcc20

    dfspcc20 Member

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    I'll see what I can find. Nothing was really abnormal, from what I remember. The midwives were concerned with her "high" fasting blood-sugar at one point. My wife started getting acupuncture after that and it returned to "normal".
     
  7. aussiedownunder

    aussiedownunder Member

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    Hi Haidut, My daughter was due to give birth on the Sunday. The previous weekend she was looking well but by the Wednesday was looking so tired and could hardly put the other children in the car she felt so drained.On the Friday her placenta tore and tests later showed she was hypothyroid. It was an emergency and thankfully both mother and baby survived. Looking back I would have said go to the doctor on the Wednesday as clearly her body / energy wasn't coping with the pregnancy any more.
     
  8. jag2594

    jag2594 Member

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    I highly doubt that the extended pregnancy resulted in a heavier baby. Ray Peat has said that after the first baby, the succeeding babies are usually larger and heavier in terms of birth weight.

    Like I said before, it's more about the quality of birth rather than quantity. You said that your wife ate a WAPF style diet while pregnant. I would considered that better than the average.
     
  9. thegiantess

    thegiantess Member

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    Interesting theory. I carried my twins to full term (for twins) and they were 13 pounds combined. At the end I could definitely feel my metabolism/ body could no longer sustain them. It became nearly impossible to move and eat and breathe.
     
  10. Koveras

    Koveras Member

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  11. dfspcc20

    dfspcc20 Member

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    @haidut
    My wife is pregnant with our 3rd child. As mentioned in my previous response above last year, she went to 42 weeks in a prior pregnancy and was induced. We're expecting that might happen again.

    Any thoughts on what tests we should watch and/or request?

    I realize it'd be ideal to let the baby gestate as long as possible, but it does get scary, since most practitioners are hesitant to work with you past 42 weeks, since the risk of stillbirth supposedly goes up after that.

    I emailed Ray about it as well. His response:
    "I’ve known people who gestated for longer than 42 weeks who were very healthy. I suspect that if the body temperature is a little below normal development takes a little longer, but usually the heavier babies with longer gestation have superior brains. I think it’s good to check thyroid, the ratio of progesterone to estrogen, vitamin D, and body temperature."
     
  12. OP
    haidut

    haidut Member

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    I think being watchful for the baby's moves is helpful. Even in pre-term week they tell you to contact them if there has been no sense of movement/kicking for 24 hours. Having a weekly ultrasound, even it is just the heartbeat one, can also help and in fact you can probably get one of those devices online and use it yourself. I am not entirely sure what all the risk of extended gestation are, but I think a lot of them are overblown as a way to push women into pre-term labow and have them induced, which increase chance of C-section (which hospitals love). Stillbirth usually involves breaking of the water, so as long as that has not happened I think it is a low risk event, but the doctor should be able to provide stats on various risks of extended gestation. Taking some vitamin E, with doctor's permission, may help keep optimal ratio of progesterone/estrogen. Vitamin E and magnesium are known as tocolytic agents, as are some NSAID drugs but I would ask a doctor first before using any of them. I think the vitamin E and magnesium would be the safest.
    Tocolytic - Wikipedia
     
  13. dfspcc20

    dfspcc20 Member

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    Thanks for the reply.

    Most of that is pretty standard. Weekly OB visits are common that far along. We did have a fetal doppler, but gave it away awhile ago. Honestly, we weren't planning on having a 3rd kid. Let this be a cautionary tale about the "pull-and-pray" method of birth control. It worked for fine for us for many years, until it didn't. :(

    I think the issue with gestation going that long is the placenta can't adequately support the baby any longer- the placenta starts to degrade and/or the baby is just too large for it. Also there's less room in the womb as the baby gets larger, making it more likely to pinch/compress the umbilical cord.

    I wasn't thinking about tocolytics, honestly, but rather something that might help induce labor if we do get to the 42+ week mark again.

    A related question- some women have relatively quick and easy labors, and some are more drawn out, lasting 24+ hours. What do you think the deciding factor is for that? I would think having a strong metabolism is a plus, but that kind of seems like a catch-22, based on the original article posted. A women's metabolism would already need to be at a breaking point in order for labor to begin. My thoughts are that a women needs to feel safe, comfortable and secure for labor to happen efficiently. Most women can't feel that way in a hospital/medical environment.
     
  14. OP
    haidut

    haidut Member

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    A woman's metabolism does not need to be at a breaking point, it just means the metabolism can no longer support the baby so the baby comes out. So, metabolism and progesterone/estrogen ratio determine how easy the labor would be.
     
  15. alywest

    alywest Member

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    It is kind of amazing how many pregnancies wind up in "emergency c-sections" these days, though. both times I was in the hospital in labor they were going on everywhere. Usually they happen if there is an issue with the baby's or mother's blood pressure or baby's pulse. My first childbirth was scary because my blood pressure skyrocketed and they were about to give me an emergency c-section because they thought I might have a stroke! I now think it was because I was undiagnosed hypothyroid, the stress of labor pushed my body too hard causing an unnatural spike in adrenaline, and it was even too weak to actually get the baby down the canal. Interestingly, an anti-anxiety medication actually brought my bp down to a normal level so I could have a natural birth. The docs ended up having to artificially break my water and induce labor with more pitocin, though.
     
  16. OP
    haidut

    haidut Member

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    Both of these are also done rather enthusiastically in hospitals as both of them increase chance of needing emergency C-section. Unless you are 2+ weeks past your due date, there is no need for any of these "interventions". Sorry to hear about your bad experience, but good job on standing your ground!
     
  17. alywest

    alywest Member

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    Actually the more I thought about it it was a medication that prevents people from going into shock. It's "what they give people who just got into a car accident," according to the nurse. She confided in my husband that they were thinking I was going to have a stroke. The blood pressure didn't go up til i got epidural and I told the anesthesiologist to turn down the drip and he did, begrudgingly, but I could tell it was too much medicine. So I guess I did stand my ground.
     
  18. OP
    haidut

    haidut Member

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    It is not surprising to have high BP due to epidural. The anesthetic has a ton of adrenaline mixed in. I wonder how they administer so care-free knowing it could cause BP issues in many people. Another convenient way to steer more people towards C-section...
     
  19. alywest

    alywest Member

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    Yeah, I suppose it means more money for them although it's awful to think that could be true. You're putting your life in these people's hands and most of them are good people but they don't know you at all. I could tell no one had ever asked the anesthesiologist to turn down the drip before. I think it was a blow to his ego, but I didn't really care at that point, I just knew something was wrong.
     
  20. OP
    haidut

    haidut Member

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    Unfortunately, it does not matter much how good they are as a person. All of them undergo an extensive "liability reduction" training at the beginning of their residency and even as students, which is then repeated as often as every quarter. The primary purpose of the hospital is NOT your well-being, it is to avoid getting sued. And adhering to FDA regulations is the best way to ensure no suit succeeds as it will be deemed "standard of care" even if it kills you quite reliably. George Bernard Shaw wrote a great piece on this titled "The Doctor's Dilemma":
    The Doctor's Dilemma, by George Bernard Shaw : PREFACE ON DOCTORS
    "...All that can be said for medical popularity is that until there is a practicable alternative to blind trust in the doctor, the truth about the doctor is so terrible that we dare not face it. Moliere saw through the doctors; but he had to call them in just the same. Napoleon had no illusions about them; but he had to die under their treatment just as much as the most credulous ignoramus that ever paid sixpence for a bottle of strong medicine. In this predicament most people, to save themselves from unbearable mistrust and misery, or from being driven by their conscience into actual conflict with the law, fall back on the old rule that if you cannot have what you believe in you must believe in what you have. When your child is ill or your wife dying, and you happen to be very fond of them, or even when, if you are not fond of them, you are human enough to forget every personal grudge before the spectacle of a fellow creature in pain or peril, what you want is comfort, reassurance, something to clutch at, were it but a straw. This the doctor brings you. You have a wildly urgent feeling that something must be done; and the doctor does something. Sometimes what he does kills the patient; but you do not know that; and the doctor assures you that all that human skill could do has been done. And nobody has the brutality to say to the newly bereft father, mother, husband, wife, brother, or sister, “You have killed your lost darling by your credulity.”"
     
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