What triggers the onset of labor in pregnancy?

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Discussion Overview

The discussion revolves around the biological triggers of labor onset in pregnancy. Participants explore various hypotheses regarding whether the signals originate from the fetus, the mother, or the placenta, and the complexities involved in understanding this process.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that the onset of labor may be triggered by factors produced by the fetus, while others propose maternal or placental signals, indicating a lack of consensus on the source.
  • It is noted that while labor can be induced with prostaglandins and oxytocin, the natural signaling process that initiates labor remains unclear.
  • One participant expresses the intuition that labor onset is likely a gradual process rather than a single event, supported by the presence of Braxton-Hicks contractions and other signs in the weeks leading up to labor.
  • Another participant shares an anecdote about a relative who experienced labor after resolving stressors, suggesting a potential connection between maternal emotional state and labor timing.
  • There is mention of a "nesting instinct" that some participants associate with the onset of labor, as they recount experiences of engaging in home projects before giving birth.
  • A question is raised about the relationship between stress during pregnancy and risks such as high blood pressure and premature labor, leading to a discussion about pre-eclampsia.

Areas of Agreement / Disagreement

Participants generally agree that the exact triggers of labor are not well understood, and multiple competing views remain regarding the sources of these signals. The discussion includes personal anecdotes and varying perspectives on the influence of stress and emotional readiness.

Contextual Notes

Limitations include the lack of definitive research on the biological triggers of labor and the complexity of factors involved, such as emotional states and physical readiness, which remain unresolved.

Kerrie
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Moonbear, hope you read this one...

I am due to have my baby in just a little under 5 weeks. Although childbirth isn't a new experience for me (at least in the last 6 years), I truly wonder what triggers labor. Is it something in the brain? Any insight (in simple terms please!) would be good to know. I am well aware of all of the little physical signs that "things are happening", but I want to know a little more on the biological aspect of it.
 
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Kerrie, yours is the million dollar question! We really don't know. Some say it's a factor produced by the fetus, others say it's something in the mother, yet others suggest it's something produced by the placenta, but they're all still guessing.

In other words, sure, we know we can induce labor with prostaglandins and oxytocin (Pitocin), but we don't know what normally provides the signal for those hormones to be released for labor to begin. Since we do know we can induce labor if necessary, the biggest reason for wanting to identify this signal is to prevent premature labor, or even be able to test for something to predict if someone is at risk for it.

My intuition says it's not going to be a single "trigger" but that it's the outcome of a gradual process that's occurring throughout that last month of pregnancy (as you're well aware, you start getting those Braxton-Hicks contractions and other signs and symptoms that your body is getting ready to go into labor over the course of several weeks). This is probably why it's so hard to pinpoint and understand, because it's probably a long progression of events rather than one single event.

I really wish I did have a good answer. I'll look later to see what the most current research says and if there is any consensus yet whether it's more likely a fetal or maternal signal or a combination of both.
 
thanks moonbear :smile:

looking forward to reading what you find...
 
ohhhh 5 weeks left! I'm getting excited for you and hope everything is just perfect.
I find its weird that we don't know what causes labor to begin. One of my sisters was due to have a child, she went past her due date and we became concerned. Then she told us, SHE was not ready, the babies room was not done, and she was really stressed with some other issues.
Once she finnished the room, and was able to relax unhindered a few days, the baby came. From that time on I always thought that the baby knew how stressed she was, and just waited for mom to relax.
 
Last edited:
Interesting hypatia, I have told myself that I want the baby to arrive after school starts (sept 12), which is certainly well before her due date, but judging by my last time, I was two weeks early.
 
hypatia said:
ohhhh 5 weeks left! I'm getting excited for you and hope everything is just perfect.
I find its weird that we don't know what causes labor to begin. One of my sisters was due to have a child, she went past her due date and we became concerned. Then she told us, SHE was not ready, the babies room was not done, and she was really stressed with some other issues.
Once she finnished the room, and was able to relax unhindered a few days, the baby came. From that time on I always thought that the baby knew how stressed she was, and just waited for mom to relax.

Funny, everyone else I know who didn't end up being induced or having a c-section scheduled has gone into labor while right in the middle of some major project. I attributed it to that nesting instinct that seems to make women decide it's time to redecorate, or repaint garage doors, or install new flooring in the living room only a few weeks before they are due. But, then again, it doesn't seem to stress out the women, but their husbands who are the ones who have to do most of the work and are suddenly left with this big project to finish as their wife is going into labor. :biggrin:

Kerrie, I haven't had a chance to look up anything yet.
 
I have been definitely having that "nesting" instinct going on...my place sparkles! Last weekend I had the urge to completely go through my kids' room (baby will have to share with them for the time being) and clean out all of the small objects that little ones like to put in their mouth. After a few hours of that, I was exhausted, but was frustrated I couldn't complete it.
 
Pardon me for being ignorant, but I haven't had any children yet. Doesn't large amounts of stress during the pregnancy increase the risk of high blood pressure (can't remember the name. Its right on the tip of my tongue!) and premature labour?

~Kitty
 
misskitty said:
the risk of high blood pressure (can't remember the name. Its right on the tip of my tongue!)
Hypertension?
 
  • #10
pre-eclampsia
 
  • #11
Pre-eclampsia was it. :biggrin: Thanks Monique. So back to the original query.

~Kitty
 

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