title: Grey zone score for hypo-osmotic swelling test (HOST) is not associated with embryo implantation defects.
abstract: OBJECTIVE
  To evaluate the clinical significance of the grey zone range (50-59%) of the hypo-osmotic swelling test (HOST) on sperm samples.
  
  
  METHODS
  Clinical and viable pregnancy rates and implantantion rates following in vitro fertilization-embryo transfer (IVF-ET) were determined in couples where the male partner scored between 50-59% on the HOST. The data were further evaluated according to the discrepancy between viability and HOST. Finally, the study assigned whether treating sperm with the protein digestive enzyme chymotrypsin had any effect on pregnancy outcome.
  
  
  RESULTS
  Pregnancy and implantation rates were comparable for couples with grey zone HOST scores with the normal IVF rate for the center. Having a large discrepancy between viability and HOST scores had no clinical significance nor did treatment with chymotrypsin.
  
  
  CONCLUSIONS
  In contrast to HOST scores < 50% where extremely poor implantation rates are noted, grey zone scores have no clinical significance.
authors.affiliation: The University of Medicine/Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden, Cooper Hospital/University Medical Center, Department of Obstetrics and Gynecology, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Check
authors.forename: D
authors.initials: D
authors.lastname: Kiefer
authors.forename: J H
authors.initials: JH
authors.lastname: Check
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.forename: D
authors.initials: D
authors.lastname: Katsoff
mesh_terms: D000328:Adult; D002918:Chymotrypsin / Q000494:pharmacology; D010064:Embryo Implantation; D004624:Embryo Transfer; D005307:Fertilization in Vitro; D006801:Humans; D007248:Infertility, Male / Q000628:therapy; D008297:Male; D009997:Osmotic Pressure; D012189:Retrospective Studies; D013094:Spermatozoa / Q000002:abnormalities* / Q000187:drug effects
chemical_list: D002918:Chymotrypsin