Last night at Panera, I managed to complete the Pelvimetry worksheet from Module Two of my midwifery school coursework. I read chapter 8 in Myles Textbook for Midwives, about structures of the pelvis and differences between pelvic types.
www.healthline.com describes the four types of pelvic types this way:
The bony pelvis has four general shapes, which may occur separately or in combination:
- Gynecoid. This is the most common pelvic shape and is best for vaginal delivery. It has an oval-shaped inlet (wider from side to side than from front to back) with parallel sides, dull ischial spines, and a pubic arch that is 90 degrees or wider.
- Anthropoid. This shape has an oval inlet but is wider from front to back than from side to side compared to the gynecoid pelvis. The sidewalls are parallel or flare outward, and the back part is roomy enough to accommodate the back of the fetus's head. This may result in the baby being born face up.
- Platypoid. This type of pelvis has an oval-shaped inlet that is compressed from front to back. This may result in a fetus that traverses the pelvis with its head in a transverse or sideways position.
- Android. This is a male-type pelvis, with a small inlet that is somewhat heart-shaped. The sidewalls converge, the ischial spines are prominent, and the pubic arch is narrow.
This youtube video explains basic pelvimetry pretty well: