title: Semen parameters, including WHO and strict criteria morphology, in a fertile and subfertile population: an effort towards standardization of in-vivo thresholds.
abstract: In this study, the semen analysis results of a fertile population were compared with those from a subfertile population, in order to establish normal cut-off values for the standard semen parameters with the aid of receiver operating characteristic (ROC) curve analysis. The fertile group comprised healthy males (n = 107) without any history of fertility problems, the partners of whom had had a spontaneous pregnancy within one year of unprotected intercourse and were pregnant at the time of the male's inclusion into the study. A total of 103 males from couples attending the infertility clinic, and with an initial sperm count of <20x10(6)/ml were recruited to form the subfertile population. The best discriminating parameter between the two populations was sperm morphology evaluated according to WHO criteria at a cut-off point of 31% normal spermatozoa. The other cut-off values were at 8% for the acrosome index, 45% for motility, and 4% normal spermatozoa for strict criteria. Recalculating the ROC curve cut-off values based on an assumed 50% prevalence of subfertility in an assisted reproductive setting, the cut-off points were reduced to 21% and 3% normal spermatozoa for WHO and strict criteria respectively. For motility, the new cut-off value was at 20% motile spermatozoa, for motility quality at 3.5 (on a scale of 1-6), the acrosome index at 3% normal acrosomes, and the teratozoospermia index at 2.09.
authors.affiliation: Reproductive Biology Unit, Department of Obstetrics and Gynaecology, Tygerberg Hospital and University of Stellenbosch, Tygerberg, 7505 South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Menkveld
authors.forename: W Y
authors.initials: WY
authors.lastname: Wong
authors.forename: C J
authors.initials: CJ
authors.lastname: Lombard
authors.forename: A M
authors.initials: AM
authors.lastname: Wetzels
authors.forename: C M
authors.initials: CM
authors.lastname: Thomas
authors.forename: H M
authors.initials: HM
authors.lastname: Merkus
authors.forename: R P
authors.initials: RP
authors.lastname: Steegers-Theunissen
mesh_terms: D000177:Acrosome / Q000473:pathology / Q000502:physiology; D000328:Adult; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007248:Infertility, Male / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D012372:ROC Curve; D012016:Reference Values; D012661:Semen / Q000502:physiology*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000002:abnormalities* / Q000502:physiology*; D014944:World Health Organization