Pelvises would not automatically get bigger just because babies» heads do, instead, women with small pelvises die in childbirth and only those with large pelvises survive. (skepticalob.com)
They are associated with the growth of the uterus, which puts pressure on the sacrum, navel, and small pelvis organs. (infobaby.org)
These impediments can be a congenitally too small pelvis or an injury to the pelvis that did not heal correctly. (breedingbusiness.com)