title: The relationship between follicle-stimulating hormone dose and level and its relevance for ovulation induction with adjuvant gonadotropin-releasing hormone-agonist treatment.
abstract: OBJECTIVE
  To investigate the effect of a GnRH agonist (GnRH-a) on the FSH threshold level and the relationship between the FSH dose and the FSH level of patients suffering from polycystic ovarian syndrome (PCOS).
  
  
  METHODS
  The stimulation with low-dose FSH in PCOS (group 1) was compared with the subsequently performed stimulation with low-dose FSH combined with GnRH-a in another group of patients suffering from the same syndrome (group 2).
  
  
  METHODS
  Specialist Reproductive Endocrine Unit.
  
  
  METHODS
  Suffering from clomiphene citrate-resistant PCOS.
  
  
  METHODS
  The FSH threshold level for ongoing follicular growth and the relationship between dose and level of FSH.
  
  
  RESULTS
  In 15 patients in group 1 and in 13 patients in group 2, respectively, 39 and 32 stimulation cycles were performed. Below and above threshold values of FSH of group 1 and 2 did not differ significantly. For the equation stable level of FSH (Y mIU/mL) = A X infusion rate of FSH (X IU/24 h) + basal level of FSH (B mIU/mL), the median A of group 1 was 0.027 and A of group 2 was 0.055 (significant difference).
  
  
  CONCLUSIONS
  In PCOS, a change of the FSH threshold level for ongoing follicular growth induced by the GnRH-a could neither be proven nor ruled out. The use of a GnRH-a resulted in larger FSH level increases per IU/24 h of FSH administered and might therefore interfere with the effect of low-dose FSH treatment.
authors.affiliation: Department of Obstetrics and Gynaecology, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Scheele
authors.forename: P G
authors.initials: PG
authors.lastname: Hompes
authors.forename: M
authors.initials: M
authors.lastname: van der Meer
authors.forename: E
authors.initials: E
authors.lastname: Schoute
authors.forename: J
authors.initials: J
authors.lastname: Schoemaker
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000627:therapeutic use; D000328:Adult; D002064:Buserelin / Q000627:therapeutic use*; D004056:Differential Threshold; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008433:Mathematics; D006080:Ovarian Follicle / Q000254:growth & development; D010061:Ovulation Detection; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy*
chemical_list: D000277:Adjuvants, Pharmaceutic; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D002064:Buserelin