I have always understood that a woman's right to abortion stems from the right to control her reproductive health (aka "body")
PLEASE READ DISCLAIMER: Before I am put in the same category as mictiv let me make it clear that this post is not intended to take any side in the abortion debate or has anything to do with the politics surrounding said debate. END OF ATTEMPT TO AVOID FLAMING.
If the above point is true then how can a woman be disallowed from prostituting herself when that is ultimately a decision of how she uses her body


"I have always understood that a woman's right to abortion stems from the right to control her reproductive health (aka 'body')"
Not exactly. It stems from an inherent right to privacy in one's dealings with one's doctor...specifically on a Constitutional right to privacy emanating from the Due Process Clause of the 14th Amendment.
"If the above point is true then how can a woman be disallowed from prostituting herself when that is ultimately a decision of how she uses her body"
Well, originally prostitution was widely legal in the USA. It was only made illegal in almost all states between 1910-1915 largely due to the influence of the Woman's Christian Temperance Union - the same group that was influential in the banning of drug use & the prohibition of alcohol.
I would definitely be in favor of legalizing prostitution as long as there were regulations that took care of any sex trafficking or health issues that sometimes go with the trade.