I wore yoga pant or those athletic skirts (the jersey knit one you can find at Old Navy for $10) to the birth center. Once labor was in full swing and I was uncomfortable, or in the tub and/or pushing I was naked..... well one with just a bra and once nude.
I'm mobile.... sorry for the typos!
Amanda- wife to DH. Mama to W (2010), L (2011), H (2013) & expecting #4 Jan 2016