The spectrum of DNA damage in human sperm assessed by single cell gel electrophoresis (Comet assay) and its relationship to fertilization and embryo development

109

Purpose To investigate the effects of male aging on semen quality, DNA fragmentation and chromosomal abnormalities in the spermatozoa of infertile patients and fertile men. Methods Semen samples of 140 infertile patients (24-76 years) and 50 men with proven fertility (25-65 years) were analyzed according to WHO guidelines. DNA fragmentation was detected by TUNEL assay, while aneuploidy was assessed by FISH. Results In the patient group, semen volume and vitality of spermatozoa decreased significantly with age, while sperm concentration showed a statistically significant increase with age. DNA fragmentation as well as disomy of sex chromosomes and disomy 8 did not show a statistically significant change with age. However, the diploidy rate was significantly increased with patient's age. In the control group, conventional semen parameters as well as DNA fragmentation and chromosomal abnormalities did not show a statistically significant with age. Conclusion Increased age in infertile men is associated with an increase in sperm concentration and diploidy, as well as a decline in semen volume and sperm vitality. However motility, morphology and DNA fragmentation are not affected by male age.

Section: Introductionmentioning

confidence: 99%

The effects of male aging on semen quality, sperm DNA fragmentation and chromosomal abnormalities in an infertile population

Brahem

Mehdi

Elghezal

et al. 2011

109

“…They also revealed that DNA damage had a positive correlation to abnormal sperm morphology but a negative correlation to sperm count. Unexpectedly, a positive correlation between DNA damage and motility was shown in the study [12]. In a study performed using the alkaline COMET assay, NTcondensed and NT-decondensed methods, Irvine et al found a significant negative correlation between sperm DNA damage and semen quality, especially in sperm count.…”

Section: Discussionmentioning

confidence: 67%

Fluctuation of “sperm DNA integrity” in accordance with semen parameters, and it’s relationship with infertility

Durmaz

Dikmen

Gündüz

et al. 2014

Purpose Nowadays sperm analysis is used routinely to assess infertile men, but it's predictive value is still restricted. For this reason, new markers are needed for diagnosis and guide treatment. A DNA damage evaluation method, which is easily applicable for routine analysis is described in this paper to provide an important support in clinical evaluation. Methods In this study, DNA damage evaluation was planned in infertile males with the COMET assay, a method which is simple, cheap, sensitive and reliable. For this purpose, the sperm DNA damage of normospermic, oligospermic, asthenospermic and teratospermic cases were investigated and the relationship between sperm parameters (sperm count, motility, morphology) and DNA damage was assessed. Results and conclusion According to our results we suggest that the factors to blame for sperm DNA damage and semen quality are the same. Also it was found that the infertile males possess substantially more sperm DNA damage than fertile men do. Improving and using the DNA damage evaluation tests seem to improve the results in ART clinics.

“…Interestingly, this observation is highly consistent with findings from studies analyzing sperm DNA fragmentation and IVF outcomes. The majority of those studies demonstrated high sperm DNA fragmentation does not preclude fertilization but negatively impacts subsequent embryo development and reduces pregnancy rates [12,13,[15][16][17]. The initial steps of embryonic development from fertilization up to the 6-8 cell cleavage stage occur essentially independent of the embryonic/ paternal genome and are predominately under the influence of maternal transcripts packaged into the oocytes at the time of ovulation [18].…”

Section: Discussionmentioning

confidence: 99%

Optimization of IVF pregnancy outcomes with donor spermatozoa

Wang

Douglas

Prosser

et al. 2009

Purpose To identify risk factors for suboptimal IVF outcomes using insemination with donor spermatozoa and to define a lower threshold that may signal a conversion to fertilization by ICSI rather than insemination. Method Retrospective, age-matched, case-control study of women undergoing non-donor oocyte IVF cycles using either freshly ejaculated (N=138) or cryopreserved donor spermatozoa (N=69). Associations between method of fertilization, semen sample parameters, and pregnancy rates were analyzed. Results In vitro fertilization of oocytes with donor spermatozoa by insemination results in equivalent fertilization and pregnancy rates compared to those of freshly ejaculated spermatozoa from men with normal semen analyses when the post-processing motility is greater than or equal to 88%. IVF by insemination with donor spermatozoa when the post-processing motility is less than 88% is associated with a 5-fold reduction in pregnancy rates when compared to those of donor spermatozoa above this motility threshold. When the post-processing donor spermatozoa motility is low, fertilization by ICSI is associated with significantly higher pregnancy rates compared to those of insemination. Conclusion While ICSI does not need to be categorically instituted when using donor spermatozoa in IVF, patients should be counseled that conversion from insemination to ICSI may be recommended based on low post-processing motility.