Aromatase Inhibitors :--How does Aromatase Inhibitors modify intra ovarian biosynthesis??

 

How does Aromatase Inhibitors modify intra ovarian biosynthesis?? Why AI(Aromatase inhibitors)?  Why not CC ?? Ans/Logic: Aromatase inhibitors have been proposed as an alternative treatment to CC therapy as the discrepancy between ovulation and pregnancy rates with CC has been attributed to its anti- oestrogenic action and oestrogen receptor depletion.

By contrast , the aromatase inhibitors suppress oestrogen production and there by mimic the central reduction of negative feedback through which CC works. Inhibition of the aromatase enzyme decreases the aromatization of androgens to oestrogens that in turn releases the hypothalamic—pituitary axis from negative feedback of oestrogen

 

 Further. adverse effects on the endometrium and cervical mucus are considerably less than CC.

 There are reports of good pregnancy rates with a lower incidence of multiple pregnancies in letrozole group . Despite the potential advantages over CC, the use of letrozole for OI was discouraged after a report at a meeting (report has not been published in a peer-reviewed journal) that suggested a significant increase in congenital cardiac and bone malformations in newborns in letrozole-treated pregnancies compare with controls which was later found to be  untrue.