i'm not sure that i agree that it's physically more difficult for humans to give birth than any other animal. i haven't read the text you mention, but that's just my general impression.
i mean, it doesn't make sense that one of the most successful animal species on the planet, which has only had advanced technology to "save" babies for the last 50 years or so, has a harder time giving birth than any other species.
i also want to point out that i don't necessarily see birth as "such a physically or emotionally trying time."
from my perspective, birth is a time of great personal power for women, a time of great spiritual and emotional potentcy, dynamic physical development and strength. That's not to say that it isn't necessarily a "challenge" or an "extreme" experience--but that experience needn't be "trying" or "difficult" from an emotional or physical perspective.
this goes to the question or difference between "pain" vs "suffering" and the psychological perspectives of what is happening at birth. for me--if you read my post in the discussion about pain during child birth--the 'pain' of child birth physically (should it come) is something that is only increasing my physical ability, helping me to broaden my physical, emotional, and spiritual limits, transitioning me to a transcendent, new space in my personhood. i welcome this challenge openly and with joy (btw, i do this with all physical pain experiences and thus have what many have considered an "off the charts threshold for pain"). In fact, i believe that pain can be a doorway to an ecstatic experience.
and thus, the experienc eof birth wouldn't be trying--emotionally or physically--but rather exciting in it's very essence and nature.
and having someone there would be ok, i guess. though i agree that it does display/demonstrate our social natures.