Something to contemplate if you are pregnant:
Researchers at Wake Forest University found that women in labor between noon and 6 p.m. received longer epidural relief from labor pain than women who labored between 8 p.m. and 2 a.m. All the women were first-time pregnancies and received the same amount of the spinal-epidural medication. Researchers believe this is due to the body’s natural rhythms that affect sleep cycles, hormones and perceptions of pain.
I found this on one of my here's-what's-happening-in-your-pregnancy websites. And the first thing that went through my mind was "Yeah because I can just pick when to be in labor". Really, I have been in labor during both time frames and had an epidural during both of those labors. I can honestly say that I don't remember there being a difference in the two. All I know is that epidurals are fantastic!