What do you think of women making the choice to have an unassisted birth?

I was just online at a pregnancy forum. Someone was discussing how they plan on having a UBAC.

What do you think of women having births unassisted by a midwife or medical professional??

Is it a matter of personal choice or does possible endangerment of baby] overcome that?

Is it completely natural?

More Information
I can’t find any reliable stats on unassisted births and rates of complications