I found a great handout that talks about this and wanted to share it. You can find it here.
In this, it discusses some reasons why fear is not beneficial for our labors and I thought I'd share my own thoughts and experiences about these.
• Increased pain for mom: Fear tends to increase muscle tension. The more tense our
bodies are, the more pain we experience.
• Possible increase in heart rate, blood pressure, and breathing rate. These can develop
because fear activates adrenaline, and a fight or flight response.
• Possible complications with labor: Adrenaline neutralizes the effect of oxytocin, the
hormone which stimulates labor contractions, which dilate the cervix, and bring baby
down through the birth canal. If fear blocks oxytocin, it may lead to longer labor, failure
to progress, more medical intervention to move labor along, or to deliver the baby.
I'll save each one of these points for later posts. I've also blogged about this quite a bit and I've added the posts under my blog series sections.