My doctor gave me almost every reason in the book! First, before he was born she went on about my "small pelvis" and the "big baby".
Pelvis: it wasn't small until I was about 38 weeks pregnant, if it was so small it is interesting no one else has ever mentioned it.
Baby: Ended up (to my surprise) a big boy. 9lb 14oz, 22 1/2 inches, 15 inch head. With a weight gain of 20 pounds this was a shocker to me.
My official documented reason is FTP after full dilation and pushing. I was in (prodromal/back, although it seemed real at the time!) labor for 3 days prior to going to the hospital. However, with an epidural and lying in bed with an OP baby this shouldn't come as a shock. He was also ascynclitic, presenting with the side of his head. I truly think that if I had been up and about during then end of my labor this would have made a huge difference.
The catheter was kinked and my bladder was huge. It "popped" out on the operating table and I've had some issues since. Thinking about a big head in a small space I'm betting that the bladder had something to do with the baby being unable to rotate. Just a guess on my part though.
Thanks for reading my novel!