http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3025806/
http://linkinghub.elsevier.com/retrieve/pii/S0015028203003455?via=sd&cc=y
The second link is just an abstract, but it's really all you need. On another IVF forum I read, a woman actually contacted the researchers who forwarded her the papers, which she posted to the forum, but it requires membership.
The downside is, yeah, it hurts like an SOB, which you knew.
Take care,
Maggie (in VA)