UroToday - The objective of this study was to determine if there was any correlation between DNA fragmentation by using terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling and standard semen parameters (WHO) and computer-aided sperm analysis (CASA) parameters. One thousand six hundred thirty-three men who were referred for evaluation of infertility which included a complete sperm analysis.

One third of the patients had a TUNEL rate (DNA fragmentation rate) of >30%. Only 7 of 21 semen parameters were strongly correlated with the DNA fragmentation analysis.

Since Sperm DNA fragmentation and decondensation now are appear to be correlated with early or late failures of assisted reproductive technologies, the authors conclude "that in the case of sperm of good quality, as defined by the World Health Organization guidelines and CASA parameters, a careful analysis of chromatin structure and DNA decays is mandatory."

Editorial Comments: DNA fragmentation studies have been employed in attempt to provide explanation for poor outcomes from Assisted Reproductive Technological interventions (IUI and IVF/ICSI). The authors of this study review the reported relationships and inconsistencies in the literature between a high percentage of fragmented sperm DNA and apoptosis markers ; sperm DNA apoptosis rates and abnormal sperm parameters; DNA fragmentation rates and unexplained recurrent pregnancy loss.

Particularly interesting findings of this study were the lack of correlation between DNA fragmentation and:

* Progressive motility after 1 hour and amplitude of lateral head displacement
* Number of spermatozoa with abnormal basal piece or circular flagella
* Morphology of head, acrosome, and intermediate piece
* Presence of leukocytes and polynuclear cells in the ejaculated sperm

Importantly, correlation was found between DNA Fragmentation and:

* Length of abstinence (positive correlation)
* Rapid progression (inverse correlation)
* Vitality (negative correlation)
* Percentage of atypical forms (positive correlation)
* Abnormal necks (positive correlation)

The lack of correlation with standard parameters is perhaps more important than the correlations. Unfortunately, this paper does not provide outcome data to assist in the interpretation of their data with regards to the predictive value of the DNA fragmentation and the WHO parameters. At this point DNA fragmentation studies will likely be reserved for patient with unexplained infertility, recurrent pregnancy loss, or failed ART cycles.

Cohen-Bacrie P, Belloc S, Ménézo YJ, Clement P, Hamidi J, Benkhalifa M
Fertil Steril. 2008 Apr 24 [Epub ahead of print]

Reported by UroToday Contributing Editor Harris M. Nagler, MD

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