Okay, I have a minute now. I know I'm jumping into this thread late, but if you don't mind, I'll write a little bit about my experience.
Two sons. Both cbirths. 1st one 8 lbs 16 oz, 20 1/2". 2nd son 10 lbs, 22". With the second son, I had no idea I was carrying such a huge baby. I am 5'4". My dh is 6'4", broad-shouldered, big. A friend joked that my body just can't handle my husband's half of the DNA. I suppose he was right.
With my first birth, I never dilated past 3 cm. The ob encouraged a section. I remember being HUNGRY mostly and weak. After 18 hours of active labor, I relented and allowed myself to be talked into a section.
With my second birth, I wanted a totally different environment and staff. So, I refused a hospital and opted for a clinic. After 16 hours, nothing. nada. So...another section.
Interestingly enough, both boys were born with IDENTICAL scars/ markings on their foreheads. Since I was in many bad car accidents, my theory is that there has been some pelvic damage. Perhaps a bone spur or calcified scar tissue is blocking the entry.
Incidentally, I am the first cbirth on both sides of my family. My mom birthed me easily. Genetically speaking, I feel like my body is programmed to successfully birth. However, I think extenuating circumstances (car wrecks) or something else has caused physical damage to my pelvis. I would love to get an x-ray, but I'm not sure if they could see everything.
Blah, blah, blah. I feel like I'm blabbing.
I will add: great outcome. The 2nd cbirth was by FAR better. In the nice, upscale hospital in the states, I got an infection and had to bedrest for 8 WEEKS after the section. In small-town Mexico, in a pretty primitive clinic, I had NO COMPLICATIONS and was up and walking the next day. I ran out of painkillers within a few days and was fine. When I ran out of painkillers with my first birth, I cried.