title: Use of letrozole challenge test to adjust gonadotropin dose in non-down-regulated cycles.
abstract: The use of a letrozole challenge test to predict ovarian response is described. The authors show that a ratio of cycle day 7 to cycle day 3 post-letrozole FSH level >1.5 is associated with poor ovarian response.
authors.affiliation: Toronto Centre for Advanced Reproductive Technology, Toronto, Ontario, Canada. bentov@lunenfeld.ca
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Bentov
authors.forename: Eliezer
authors.initials: E
authors.lastname: Burstein
authors.forename: Navid
authors.initials: N
authors.lastname: Esfandiari
authors.forename: Robert F
authors.initials: RF
authors.lastname: Casper
mesh_terms: D047072:Aromatase Inhibitors; D015415:Biomarkers / Q000097:blood; D004334:Drug Administration Schedule; D004958:Estradiol / Q000097:blood; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D043373:Follicle Stimulating Hormone, Human / Q000097:blood; D006062:Gonadotropins / Q000008:administration & dosage*; D006801:Humans; D000077289:Letrozole; D007986:Luteinizing Hormone / Q000097:blood; D009570:Nitriles; D009864:Ontario; D010050:Ovarian Function Tests; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000379:methods*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014230:Triazoles
chemical_list: D047072:Aromatase Inhibitors; D015415:Biomarkers; D005300:Fertility Agents, Female; D043373:Follicle Stimulating Hormone, Human; D006062:Gonadotropins; D009570:Nitriles; D014230:Triazoles; D004958:Estradiol; D000077289:Letrozole; D007986:Luteinizing Hormone