Completely unnecessary, as others have said.
Having said that, like most of these things, your choice.
I'm afraid that even though I have good personal hygiene, I find that when I exercise or exert myself, I tend to get a bit disproportionately sweaty around my fanny, and it can be a little bit 'high' smelling at times if I'm not in a position to wash/ change straight away. I've found this is generally linked to how hairy it is- I think my hairs must really trap odours. NICE. Maybe this is entirely my imagination (it probably is- but it's my imagination and I have to live with it, not you, so I will decide what I do with it
).
So, not for the birth itself, but just in general, I plan to keep it short, and waxed and the sides where it has a tendency to go a bit like tom hanks at the end of castaway.
I'm only about 16 weeks at present though. If this was a film it would cut to me, in approximately a month's time, saying 'ah fuck it, let it go wild!!'