title: Histological dating of timed endometrial biopsy tissue is not related to fertility status.
abstract: OBJECTIVE
  To assess the ability of histological dating to discriminate between women of fertile and infertile couples. The utility of histological dating of endometrium in the evaluation of infertile couples is uncertain.
  
  
  METHODS
  Prospective multicenter study, with subjects randomly assigned to biopsy timing. Criterion standard for infertility was 12 months of unprotected, regular intercourse without conception and for fertility at least one live birth within 2 years.
  
  
  METHODS
  University-based infertility practices.
  
  
  METHODS
  Volunteer subjects (847) recruited at 12 clinical sites participating in the National Institutes of Health-funded Reproductive Medicine Network. Inclusion criteria included ages 20-39 years, regular menstrual cycles, and no hormonal treatment or contraceptive use for 1 month before the study. Fertile controls were excluded if they had a history of infertility, recurrent pregnancy loss, or recent breastfeeding.
  
  
  METHODS
  Subjects underwent daily urinary LH testing. After detection of the LH surge, subjects were randomized to biopsy in the mid (days 21-22) or the late (days 26-27) luteal phase. Pathologists at each site estimated the cycle day based on standard criteria. For the primary analysis, an out-of-phase biopsy was defined as a greater than 2-day delay in the histological maturation of the endometrium.
  
  
  METHODS
  The proportion of out-of-phase biopsies in fertile and infertile women was compared using logistic regression models with age at randomization as a covariate. Comparisons were also made between fertile vs. infertile at the midluteal or late luteal phase time points.
  
  
  RESULTS
  Biopsies were evaluated (301 mid and 318 late; N = 619). Out-of-phase biopsy results poorly discriminated between women from fertile and infertile couples in either the midluteal (fertile: 49.4%, infertile: 43.2%) or late luteal phase (fertile: 35.3%, infertile 23.0%). Results did not substantially differ using alternative definitions of "out-of-phase" or standardized cycle day.
  
  
  CONCLUSIONS
  Histological dating of the endometrium does not discriminate between women of fertile and infertile couples and should not be used in the routine evaluation of infertility.
authors.affiliation: Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA. ccoutifaris@obgyn.upenn.edu
authors.forename: Christos
authors.initials: C
authors.lastname: Coutifaris
authors.forename: Evan R
authors.initials: ER
authors.lastname: Myers
authors.forename: David S
authors.initials: DS
authors.lastname: Guzick
authors.forename: Michael P
authors.initials: MP
authors.lastname: Diamond
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Carson
authors.forename: Richard S
authors.initials: RS
authors.lastname: Legro
authors.forename: Peter G
authors.initials: PG
authors.lastname: McGovern
authors.forename: William D
authors.initials: WD
authors.lastname: Schlaff
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Carr
authors.forename: Michael P
authors.initials: MP
authors.lastname: Steinkampf
authors.forename: Susan
authors.initials: S
authors.lastname: Silva
authors.forename: Donna L
authors.initials: DL
authors.lastname: Vogel
authors.forename: Phyllis C
authors.initials: PC
authors.lastname: Leppert
mesh_terms: D000328:Adult; D001706:Biopsy; D004717:Endometrium / Q000473:pathology*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000473:pathology* / Q000652:urine; D016015:Logistic Models; D008183:Luteal Phase; D007986:Luteinizing Hormone / Q000652:urine; D011446:Prospective Studies
chemical_list: D007986:Luteinizing Hormone