LeBFG, I think where fear comes from is really really misunderstood and not really known.
I think this is something that needs research rather than to make assumptions about.
The most common one I see, is that it comes from TV.
The next is from women sharing birth horror stories with each other.
Both annoy me, as I can not relate to this.
I first started saying I didn't want children when I was about 10 or 11. There was no reason for it. None at all. No one around me told me horror stories or spoke in a way I consider to be negative. I didn't watch stuff on tv that left me with this fear. It just sort of 'happened'.
And actually when they have looked at this in studies for primary tokophobia, the very basis picture they seem to have is that it often comes from childhood; usually at a similar age. They think it might come from a trigger - maybe the way a mother talks about birth or seeing something but they don't know and there doesn't seem to always be something there.
In my experience I genuinely can't pin point something 'bad'. The only thing is the fact my Mum had me by EMCS, but she's never really talked about it much other than to say I was in distress, late and needed to come out. Nothing scary or particularly emotive; she's always been pretty neutral in what she said.
I think my point is, that I do believe that, perhaps a good deal of fear is quite deep and goes back far further than we might initially give credit for.
Unless we understand where its coming from, how can you start to change it?