The story, true or not, is that Louis XVI wanted to see the birth of his son, and asked the obstetrician if he could place the queen (Marie Antoinette) on her back with her legs extended to facilitate this. The obstetrician realized that this position made things much easier for him as well – he didn’t have to stoop down and look up at the standing or squatting woman, which was not only difficult physically but socially demeaning. So he continued to use this position for delivering babies, and other obstetricians picked up the practice quickly. I don’t think there was actually a law concerning this, but I could be wrong. In any case, this position has continued to be favored by obstetricians and is used to this day in many hospitals, despite the fancy birthing beds that grace the birthing rooms. “Can you break down the bed now?” is a refrain that labor nurses hear whenever the laboring woman is approaching the second stage of labor or is about to push her baby out.  Could it be that the supine or lithotomy position puts the obstetrician and not the woman in control?  It is difficult to feel a sense of  power or control when you are lying on your back like a stranded beetle, with your private parts exposed to everyone in the room, while the doctor stands over you in his/her obstetric garb.  Midwives favor letting the woman assume whatever position works best for her.