title: Quantifying the intraindividual variation of antimüllerian hormone in the ovarian cycle.
abstract: OBJECTIVE
  To quantify intraindividual variability of antimüllerian hormone (AMH) as analytical and biological coefficients of variation and assess the effects of variation on clinical classification.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Thirty-eight women referred by general practitioners.
  
  
  METHODS
  None.
  
  
  METHODS
  Total intraindividual variability (CVW), analytical (CVA) and biological variability (CVI) for each woman and for AMH ranges: low (<5 pmol/L), reduced (5-10), moderate (>10-30) and high (>30 pmol/L), with calculation of proportion of women crossing clinical cutoffs and expected variability around each cutoff.
  
  
  RESULTS
  Cycling women (n = 38) contributed 238 blood samples (average 6 samples each). The average total intraindividual AMH variability was 20% (range: 2.1% to 73%). Biological variation was 19% (range: 0 to 71%) and at least twice the analytical variation of 6.9% (range: 4.5% to 16%). Reclassification rates were highest in women with low (33%) or reduced AMH (67%) levels. Expected variations around the 5, 10, and 30 pmol/L cutoffs were 3-7, 7-13, and 20-40 pmol/L, respectively. In a woman with mean AMH in the 10-30 pmol/L range, the span of results that could occur was 7-40 pmol/L.
  
  
  CONCLUSIONS
  Total variation in AMH was 20%, and the majority of this was biological. Changes in AMH resulted in reclassification in 29% of women and occurred most frequently in those with low and reduced AMH. In cycling women, the variability in AMH should be considered by clinicians, especially if a result is close to a clinical cutoff.
authors.affiliation: Department of Biochemistry, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia; Western Diagnostic Pathology, Myaree, Western Australia, Australia. Electronic address: narelle.hadlow@health.wa.gov.au.
authors.forename: Narelle
authors.initials: N
authors.lastname: Hadlow
authors.affiliation: Department of Endocrinology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Brown
authors.affiliation: Western Diagnostic Pathology, Myaree, Western Australia, Australia.
authors.forename: Afsana
authors.initials: A
authors.lastname: Habib
authors.affiliation: Department of Biochemistry, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Wardrop
authors.affiliation: Department of Biochemistry, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Joseph
authors.affiliation: Western Diagnostic Pathology, Myaree, Western Australia, Australia.
authors.forename: Melissa
authors.initials: M
authors.lastname: Gillett
authors.affiliation: Department of Biochemistry, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia.
authors.forename: Rhonda
authors.initials: R
authors.lastname: Maguire
authors.affiliation: Western Diagnostic Pathology, Myaree, Western Australia, Australia.
authors.forename: Johan
authors.initials: J
authors.lastname: Conradie
mesh_terms: D000328:Adult; D054304:Anti-Mullerian Hormone / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000097:blood*; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D054304:Anti-Mullerian Hormone
keywords: AMH; analytical variation; biological variation