>>212267200 (OP)
This is kinda predictable from an evolutionary perspective. As nutrition becomes better, and food becomes easier to obtain, females will gestate larger offspring. Once the size of a baby's skull and shoulders passes a certain point, natural child birth will become impossible because women of average size today don't have a wide enough opening in their pelvis to give birth. If the pelvis gets much wider, women wouldn't be able to walk efficiently. Solution: make females taller and larger.