title: Reliability of follicle-stimulating hormone measurements in serum.
abstract: BACKGROUND
  Follicle-stimulating hormone (FSH), a member of gonadotropin family, is critical for follicular maturation and ovarian steroidogenesis. Serum FSH levels are known to fluctuate during different phases of menstrual cycle in premenopausal women, and increase considerably after the menopause as a result of ovarian function cessation. There is little existing evidence to guide researchers in estimating the reliability of serum FSH measurements. The objective of this study was to assess the reliability of FSH measurement using stored sera from an ongoing prospective cohort--the NYU Women's Health Study.
  
  
  METHODS
  Sixty healthy women (16 premenopausal, 44 postmenopausal), who donated at least two blood samples at approximately 1-year intervals were studied. An immunoradiometric assay using a sandwich monoclonal antibodies technique was used to measure FSH levels in serum.
  
  
  RESULTS
  The reliability of a single log-transformed FSH measurement, as determined by the intraclass correlation coefficient, was 0.70 for postmenopausal women (95% confidence interval (CI), 0.55-0.82) and 0.09 for premenopausal women (95% CI, 0-0.54).
  
  
  CONCLUSIONS
  These results suggest that a single measurement is sufficient to characterize the serum FSH level in postmenopausal women and could be a useful tool in epidemiological research. For premenopausal women, however, the reliability coefficient was low, suggesting that a single determination is insufficient to reliably estimate a woman's true average serum FSH level and repeated measurements are desirable.
authors.affiliation: New York University School of Medicine, New York, NY, USA. akhmea01@med.nyu.edu
authors.forename: Alan A
authors.initials: AA
authors.lastname: Arslan
authors.forename: Anne
authors.initials: A
authors.lastname: Zeleniuch-Jacquotte
authors.forename: Annekatrin
authors.initials: A
authors.lastname: Lukanova
authors.forename: Sabina
authors.initials: S
authors.lastname: Rinaldi
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Paolo
authors.initials: P
authors.lastname: Toniolo
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D015592:Immunoradiometric Assay; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood; D017697:Premenopause / Q000097:blood; D015203:Reproducibility of Results
chemical_list: D005640:Follicle Stimulating Hormone