O33.2: Maternal care for disproportion due to inlet contraction of pelvis

During your pregnancy it was thought, or it was established, that the size of your pelvis and the size of your child are not a good match.

In the pelvis there are various pelvic bones. At the back of the body the pelvic bones are connected to the sacrum of the spinal column. There is a joint on either side of the sacrum for this purpose. The pelvic bones plus the sacrum form the bony pelvic ring or girdle. In front, the pelvic bones are tightly joined to one another by ligaments and cartilage fiber.

There are different levels within the pelvis. During the birth the child must pass through the different levels. The child first passes through the pelvic inlet, then the midpelvis, and finally the pelvic outlet. In a normal birth the child passes through the pelvis head first. If the child’s head is to be able to pass through the different levels, it has to turn in different places.

The size of your pelvis and the size of your child are not a good match because the entrance to your pelvis is too narrow.

If the size of the pelvis and the child are not a good match, this can cause problems and, for example, make the birth take longer or make a Caesarean necessary.