title: Precision of progesterone measurements with the use of automated immunoassay analyzers and the impact on clinical decisions for in vitro fertilization.
abstract: OBJECTIVE
  To compare the precision of progesterone measurements obtained with the use of immunoassays and of liquid chromatography-tandem mass spectrometry (LC-MS/MS).
  
  
  METHODS
  Comparative study.
  
  
  METHODS
  Academic, private practice, and in vitro fertilization (IVF) research centers.
  
  
  METHODS
  A total of 189 human serum samples were collected during controlled ovarian hyperstimulation and early pregnancy in women undergoing IVF.
  
  
  METHODS
  Serum progesterone pools (n = 10; 0.2-4 ng/mL) were sent to four laboratory centers that used four different automated immunoassay analyzers. Progesterone was measured by immunoassay in triplicate at three separate time points (n = 9 per pool) and by LC-MS/MS in triplicate once (n = 3 per pool).
  
  
  METHODS
  Inter- and intraassay coefficients of variation (CVs) of progesterone measurements were compared for each analyzer and LC-MS/MS.
  
  
  RESULTS
  Progesterone measurements by immunoassay were highly correlated with those by LC-MS/MS. Only two analyzers had intraassay CVs <10% at all three experimental time points, and only two analyzers had an interassay CV <10%. Mean progesterone levels by the analyzers were different across multiple progesterone pools.
  
  
  CONCLUSIONS
  Our results indicate that progesterone threshold measurements used for IVF clinical decisions should be interpreted cautiously and based on laboratory- and method-specific data. A validated progesterone standard incorporated into daily immunoassays could improve medical decision accuracy.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon. Electronic address: pattonp@ohsu.edu.
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Patton
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, Oregon.
authors.forename: Jeong Y
authors.initials: JY
authors.lastname: Lim
authors.affiliation: Pacific Northwest Fertility, Seattle, Washington.
authors.forename: Lee R
authors.initials: LR
authors.lastname: Hickok
authors.affiliation: San Diego Fertility Center, San Diego, California.
authors.forename: L Michael
authors.initials: LM
authors.lastname: Kettel
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon.
authors.forename: Janine M
authors.initials: JM
authors.lastname: Larson
authors.affiliation: Endocrine Technology and Support Core, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon.
authors.forename: K Y Francis
authors.initials: KY
authors.lastname: Pau
mesh_terms: D057205:Automation, Laboratory / Q000592:standards; D015415:Biomarkers / Q000097:blood; D002853:Chromatography, Liquid / Q000592:standards; D004867:Equipment Design; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000592:standards*; D007246:Infertility / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D059021:Laboratory Proficiency Testing; D015588:Observer Variation; D010062:Ovulation Induction; D018579:Patient Selection; D011237:Predictive Value of Tests; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000097:blood*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D053719:Tandem Mass Spectrometry / Q000592:standards; D014481:United States
chemical_list: D015415:Biomarkers; D011374:Progesterone
keywords: Progesterone levels in IVF; automated analyzers; mass spectrometry