^Not sure what you mean, GnRH agonists are widely available. That sentence could sound better though.  In regards to the placental stuff, there's also evidence for GnRH induced CXC chemokine expression in placental trophoblasts, affecting lymphocyte recruitment (see http://ajpcell.physiology.org/cgi/pdf_extract/297/1/C4 and original article by Babwah et al). But to be honest the whole section needs a re-write. GnRH is important for cardiac development in zebrafish for example, but then there's no mention of other forms of GnRH (GnRHII, GnRHIII), just a focus on mammalian GnRHI. So a whole lot of work to be done.    