Progress of letrozole in ovarian stimulation

Letrozole is the third-generation aromatase inhibitor.It could induce ovulation by inhibiting estrogen production,with the result of releasing the hypothalamic-pituitary axis from estrogenic negative feedback and increasing the synthesis of follicle-stimulating hormone.Clinical trials indicated that letrozole could be safely and effectively used in ovulation induction of anovulatory women,especially those who were clomiphene resistant,and also in assisted reproductive technology.In addition,it can be used in controlled ovarian stimulation for the purpose of fertility preservation in young women with breast cancer.This article mainly focuses on the progress of letrozole in ovulation induction.