title: The accuracy and reproducibility of the endometrial receptivity array is superior to histology as a diagnostic method for endometrial receptivity.
abstract: OBJECTIVE
  To compare the accuracy and reproducibility of the endometrial receptivity array (ERA) versus standard histologic methods.
  
  
  METHODS
  A comparative prospective study (May 2008-May 2012).
  
  
  METHODS
  University-affiliated infertility clinic.
  
  
  METHODS
  Eighty-six healthy oocyte donors, regularly cycling, aged 20-34 years with a body mass index (BMI) of 19-25 kg/m(2).
  
  
  METHODS
  Endometrial biopsies were collected throughout the menstrual cycle. For the accuracy study, 79 samples were grouped into two cohorts: the training set (n = 79) for ERA machine-learning training and dating, and a dating subset (n = 49) for comparison between histologic and ERA dating. For the reproducibility study, seven women underwent ERA testing and it was repeated in the same patients on the same day of their cycle 29-40 months later.
  
  
  METHODS
  Concordance of histologic and ERA dating related to LH as a reference, and interobserver variability between pathologists were statistically analyzed by the quadratic weighted Kappa index. The ERA reproducibility was tested and its gene expression visualized by principal component analysis.
  
  
  RESULTS
  For each pathologist, concordance against LH peak yielded values of 0.618 (0.446-0.791) and 0.685 (0.545-0.824). Interobserver variability between pathologists yielded a Kappa index of 0.622 (0.435-0.839). Concordance for ERA dating against LH peak showed a value of 0.922 (0.815-1.000). Reproducibility of the ERA test was 100% consistent.
  
  
  CONCLUSIONS
  The ERA is more accurate than histologic dating and is a completely reproducible method for the diagnosis of endometrial dating and receptivity status.
authors.affiliation: Fundación IVI, Instituto Universitario Instituto Valenciano de Infertilidad, University of Valencia, Valencia, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Díaz-Gimeno
authors.forename: Maria
authors.initials: M
authors.lastname: Ruiz-Alonso
authors.forename: David
authors.initials: D
authors.lastname: Blesa
authors.forename: Nuria
authors.initials: N
authors.lastname: Bosch
authors.forename: José A
authors.initials: JA
authors.lastname: Martínez-Conejero
authors.forename: Pilar
authors.initials: P
authors.lastname: Alamá
authors.forename: Nicolás
authors.initials: N
authors.lastname: Garrido
authors.forename: Antonio
authors.initials: A
authors.lastname: Pellicer
authors.forename: Carlos
authors.initials: C
authors.lastname: Simón
mesh_terms: D000328:Adult; D001185:Artificial Intelligence; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D010061:Ovulation Detection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers