Semen parameters, including WHO and strict criteria morphology, in a fertile and subfertile population: an effort towards standardization of in-vivo thresholds.
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.
Menkveld
R
R
Reproductive Biology Unit, Department of Obstetrics and Gynaecology, Tygerberg Hospital and University of Stellenbosch, Tygerberg, 7505 South Africa.
Wong
W Y
WY
Lombard
C J
CJ
Wetzels
A M
AM
Thomas
C M
CM
Merkus
H M
HM
Steegers-Theunissen
R P
RP
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