"Anthracite actually anyone can give birth without pain relief, if they're not given any."
This point is largely irrelevant to this discussion.
90% of women in the UK give birth in units where epidurals and opioids are available. Only 1 in 10 women nationally answers a categorical 'no' to the question 'did you get the pain relief you needed in labour?'. So most women have access to pain relief if they need it. Some women make an informed choice not to use it. Sometimes it's an easy choice as the women have straightforward and fast labours which they find manageable, and sometimes it's a hard choice to make as some women who opt to go without pain relief will have long, painful and difficult labours. The operative word is choice. To imply that there is generally no choice to be made as to how a labour is managed in relation to pain relief is usually false.
"there are those amongst us who feel that denial of epidural led us to more risky forms of delivery- instrumental, emergency section etc- because we were so utterly exhausted."
Given the number of women who opt for an epidural in the UK, I suspect that if there was evidence that it was linked to lower rates of c/s and instrumental birth it'd come to light?
"I've never actually seen any research on whether women who are not given the pain relief they need are more likely to end up with complex deliveries"
Epidural can be a useful tool in some complex births and may allow some women to avoid a c/s or perhaps even an instrumental birth by allowing the mother to get some rest and regain her strength to push her baby out. I have no problem with this idea. However, the evidence from the UK suggests that overall epidurals seem to cause more physiological problems with birth than they resolve.
"Oh, and deciding what pain relief you want before you experience labour is at best a choice made based on pure ignorance- can't be otherwise- and at worst deranged. If you know you can't have pain relief because of whatever reason, that's one thing, you have no choice. But not when you actually have options! "
Don't be silly. It's quite reasonable to feel that you don't want to use opioids of have an epidural. If women have a strong feeling that they don't want to use drugs in labour it's very helpful for this to be acknowledged beforehand so that they can organise the sort of care in labour, and access a birth environment, which will maximise their chances of not needing pain relief. If we went by your logic all women would be advised to book into a CLU 'just in case' they need an epidural!