There are two factors at play.
One, humans have “unnaturally” large heads at birth, due to our large brains. At the same time our pelvises have a particularly narrow hole due to our adaptation to upright walking. Those do cause some issues.
Two is something that compounds one. Women are forced to give birth laying on their backs for the benefit of the doctor overseeing the birth, which is thoroughly unnatural. Traditionally birth was (and in many places still is) performed squatting (or perhaps sitting as well, I’m not entirely sure about that), which lets gravity aid with the birth, and puts less strain on the mother’s body.
Latest Answers