Conference turris::womannotes-v2

    During pregnancy, certain hormones are secreted by the woman's body
    that actually soften the bones of the pelvis (and elsewhere if I
    am not mistaken). A similar hormone is present in the fetus which
    serves to keep the bones somewhat pliable to allow the child the
    easiest possible passage through the birth canal into the light
    of day.                            
    
    I believe there is some shape changing due to the weight of the
    fetus in the pelvic and pubic bones. Most of the shape change occurs
    during the second stage of labor, I believe.
    
    Mark

    Re: .0
    
    Where do babies come from......?
    
    
    Why, from the stork, of course.
    
    Shhesh, I thought everyone knew that. :-)
    
      Alan

    Mark,
    
    The bones do not soften or get more pliable. To do that they would
    have to turn to cartilage. What happens is that the ligaments holding
    the bones together relax under the influence of hormomes so that
    the two pelvic bones move apart in the front.

    Further the bones in the baby's body (the skull in particular) are
    not soft either. Rather the joints (sutures) between the skull bones
    have not yet fused. This allows the skull bones to move during
    birth, causing the baby's head to be compressed during birth. These
    sutures close after the baby is born (the 'soft' spot is the largest
    one).
       
    Bonnie

Thank you, Bonnie.  Know I know why my phys. book has those funny ligaments
there.

    Thanks, Bonnie. I was just relaying the information that my birthing
    class instructor gave us last week. I stand corrected. Armed with
    this new knowledge, I'll take her to task this week and see if she
    was really only informing us in a general sense or what. You're
    correct. As I previously stated, I'm not a doctor. And she's only
    an RN.
    
    Mark

   Mark,
    
    If the bones actually soften that is news since I last taught
    a course in anatomy 8 years ago. :-) Have her give references!
    
    Bonnie

    Given that the majority of her audience is not from a technical
    background, she may have seen fit to gloss over the details in such
    a way that the mechanics involved were incorrectly presented. I
    am certainly not disputing your claim as you have shown beyond question
    that you are far more attuned to biology than I am. Since high school
    biology (97 for the course) I haven't had any occasion to further
    study that field. It is obvious from having read your notes that
    you have alot more experience and knowledge in that area than I
    do and I would not propose that it were otherwise. To do so would
    certainly insult you as much as it would insult me if you asserted
    that your knowledge of fishing were as extensive as mine (although
    you probably stand a better chance of knowing as much about fishing
    as I do than me knowing about bio). On the contrary, I simply want
    her to explain things in an accurate, technical manner. She said
    the bones soften and I swallowed it, having no other knowledge upon
    which to base a question. Now that I have such knowledge, I will,
    in fact, ask her to either cite sources or direct me to appropriate
    literature. My problem isn't inability to understand, it's more
    like where to look.
    
    Mark

    Mark,
    
    I appreciate where you are coming from. The last remark was meant
    to be a silly one. And having been away from teaching now for
    almost 8 years my memory for details is wearing a bit and I do
    forget things. 
    
    Bonnie

    	Specifically, the hormones are prostaglandins and they are
    also reponsible for relaxing smooth muscle tissue which why pregnant
    women experience heartburn (the sphincter at the top of the stomach is
    not as efficient) and constipation (Ditto for the intestines). 
    This loosening of the ligaments as also why pregnant women are told
    not to lift large weights - you're more easily injured.            
    
    tlh
    5 month prego who's been reading a lot lately :-)
    
    
    	  

    I am reminded that tendons (muscle to bone attachments) as well
    as ligaments (bone to bone) relax during pregnancy. I focused
    in on the ligaments to explain about the bone situation.
    
    Bonnie

    Side note: All of this is one reason why women have back problems
    during (and sometimes after) pregnancy. Therapeutic massage is an
    excellent idea at this time.
    
    --DE
    

    When Arlene was pregnant last, she became a terrible snorer. I mean,
    like, really, _really_, loud. Near the end it got so loud that we
    would trade sleeping on the couch. Since then, however, it has stopped
    (or at least gone back down to normal ignorable volumes).
    
    At first we thought that it was just because she had to sleep on
    her back, but that wasn't it, she was just as loud on her side,
    and her sleeping position is the same now.
    
    I was just wondering if it could have been due to those hormones,
    and if anyone else has experienced this.
                                                   
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    Bonnie, in cases (like myself) where the woman has to have a C-section
    because the baby's head won't fit through the pelvic bones, is that
    because whatever is described here as happening doesn't happen -
    or is it that it does happen, and there still isn't room for the
    baby to get through?
    
    Thought you might know.
    
    Lorna
    

    Lorna,
    
    I don't know about every case, but mine was like yours, there
    still wasn't room for the baby to get through. From what I
    have read that is the most common situation.
    
    The human is at the very outer edge of the head size of the
    baby to mother's birth canal ratio. We actually carry our
    babies just a bit too long for optimum ease of delivery tho
    quite a bit too short as far as the ability of the infant to
    cope after birth (compared to other primates and mammals.)
    
    Bonnie

    	RE:  .14
    
    	Agreed.  To put it another way, one of the reasons that human
    	infants come into the world in a much more "helpless" state
    	than other primates and mammals is because humans are born
    	at around the time when the baby's head reaches the maximum
    	size it can grow (and still have a chance of the baby
    	being delivered vaginally.)

    	Depending on the size of the Mother's pelvis, some babies
    	are delivered past the point of having a head small enough to 
    	make it through the birth canal safely (thus, a C-section is 
    	required.)

    	If not for this problem with the infant head to Mother's pelvis
    	ratio, human infants would likely enjoy a much longer gestation
    	period (which would enable them to be born closer to the level of
    	development that other primates and mammals have at birth.)

    re: .12 (Steve)
    
>    I was just wondering if it could have been due to those hormones,
>    and if anyone else has experienced this.
    
    	   Based on the research I have done, I think I can provide
    	a more likely explanation.
    
    	   During pregnancy the uterus expands dramatically, and in
    	the process displaces other internal organs (notably, the 
    	diaphragm, the stomach, and even the heart).  In some cases
    	the pressure is such that the heart is pressed up against
    	the esophagus, causing the woman to 'feel her heart in her
    	throat'.  This same pressure applied in just the wrong way
    	could potentially induce excessive snoring, as the upper
    	esophageal airway becomes distended/compressed (depending
    	on the way the pressure is applied).
    
    	   Did your wife experience the 'heart in the throat' syndrome?
    
    	- Greg

    re .16:
    
    Thanks for the analysis. Isn't the esophagus the tube to the stomach?
    Isn't the airway the trachea? Isn't snoring caused by "flapping"
    of the soft palate?
                            
    > Did your wife experience the 'heart in the throat' syndrome?
                                           
    She never mentioned it, but I'll ask. 
    
    {now where did I say she was my wife?  :-)  Be careful with
    assumptions. We _are_ married, but I have become sensitized to the
    connotations of the phrase "my wife" so I try to avoid using it.} 
                                                   
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    re: .18 (Steve)
    
>    Thanks for the analysis. Isn't the esophagus the tube to the stomach?
>    Isn't the airway the trachea? Isn't snoring caused by "flapping"
>    of the soft palate?
    
    	   Correct, but the way the book described it, it sounded
    	very much like this might be a related problem.  The 'heart
    	in the throat' syndrome was what led me to conclude there
    	might be some relation.  The book ("Maggie's Woman's Book",
    	chapter two) is rather sketchy on the details, and does not
    	mention snoring directly.  
    
>    {now where did I say she was my wife?  :-)  Be careful with
>    assumptions. We _are_ married, but I have become sensitized to the
>    connotations of the phrase "my wife" so I try to avoid using it.} 
    
    	   Whoops... sorry, old bean... it won't happen again.
    
    	- Greg