Volume 12, Issue 1 (January 2010) 12, 47–58; 10.1038/aja.2009.14
Clinical significance of the low normal sperm morphology value as proposed in the fifth edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen
Roelof Menkveld
1Andrology Laboratory, Department of Obstetrics and Gynaecology, Tygerberg Academic Hospital and University of Stellenbosch, Tygerberg 7505, South Africa
Correspondence: Dr Roelof Menkveld, E-mail: rme@sun.ac.za
Received 25 December 2008; Revised 15 January 2009; Accepted 23 January 2009
Abstract |
The very low cut-off value for sperm morphology of 4% morphologically normal spermatozoa, as proposed in the new edition of the World Health Organization (WHO) manual on semen analysis, is in agreement with recently published values and reflects the trend of a decline in reported mean values for normal sperm morphology. The reduced value for morphologically normal spermatozoa over the years may be due to several factors. The first is the introduction of strict criteria for the evaluation of sperm morphology. Other reasons may include the introduction of additional criteria for sperm morphology abnormalities and the suggested decrease in semen parameters because of increasing negative environmental influences. Although on its own the newly proposed very low normal value may not provide the strong predictive value for a males' fertility potential, as originally reported for sperm morphology evaluated according to strict criteria, a good predictive value can still be obtained if the holistic, strict approach for sperm morphology evaluation is followed together with additional sperm morphology parameters now available, because certain morphology patterns and sperm abnormalities are now known to be of strong prognostic value. In addition, better international standardization of the technical methodology, consensus on the interpretation of sperm morphology evaluation criteria and standardized international external quality control (EQC) schemes, are of utmost importance to maintain the good predictive value of sperm morphology.
Keywords: male fertility potential, normal cut-off values, semen analysis, sperm morphology evaluation, strict criteria, WHO manual
PDF |
PDF |
|
|
Browse: 21107 |
|