As a baby midwife I was taught to do pelvimetry on all nulliparas. As I grew as a midwife I realized it was mostly non important information that was uncomfortable for both mama and midwife and the best pelvimetry is a baby and it's mother's pelvis in labor. As a middle aged midwife I don't employ it in my practice but I do measure (nulliparas, ybac'ers or a woman who has been told previously that her pervis was too small) the pelvic outlet by fitting my fist between the ishcial spines while mama is in a reclined position and with her panties or clothes still on. I find this outlet doesn't change in labor and it can be very reassuring for mama to hear 'you've got plenty of room and a nice rounded pubic arch'.
A couple weeks ago I was in labor with a mama, no ve's during pregnancy and most of labor, she had a great pelvic outlet. When she first called to describe labor patterns and feelings she described a constant pubic bone pain and I thought to my self that perhaps there was a narrow pubic inlet, but, that can change. At birth as we got to end of 1st stage, I did a ve and found the weirdest pubic bone I have ever felt. It was thick and rough edged on mama's right side at the crest of the bone. Knowing this imediately made me question whether baby could pass through this bone or not but that was not for me to decide at that moment. We tried patience, positional changes, rest, the tub, everything I knew to get baby to come by this bone. After many, many hours and mama feeling satisfied that we had done all that we could, we transported, OB felt the pubic and bone and heard our story and off for a cs mama went. Baby had really tried to come, evident by the head moulding but just could not navigate this bone. Would pelvimetry have changed this outcome? No, but at least we had no fear about trying to birth normally and gave her baby the many benefits from a naturally occurring labor.
As the previous poster said, understanding pelvic anatomy is important, but I don't find pelvimetry to be of a benefit, prenatally. Situations like breech and unusual lies may benefit from pelvimetry but those things can change right up to the moment of birth so a clinical diagnosis of inadequate pelvis is cruel and premature.
I am just playing devil's advocate here, and I really appreciate your statement and I take it to heart but, what if your midwife was mapping your pelvis so that she could better understand what position(s) would help you in birth and or to really understand you babys' position at the time? I know I have done this and the information gained at this moment can be invaluable. Could this have been the case?