I was chatting with a horse girl a while back... the kind that works in veterinary medicine... and made the question 'If horses are so fragile and so prone to birth accidents, how do they give birth in the wild and without medical help?'
Her answer was, 'Just like humans. They die A LOT. Childbirth is one of the riskiest things any mammal can go through, and it fails frequently, often with deadly consequences.'