Guidelines on sperm DNA fragmentation testing

Sperm DNA fragmentation index and cumulative live birth rate in a cohort of 2,713 couples undergoing assisted reproduction treatment

OBJECTIVE

To study how the choice of the first assisted reproductive technology treatment type affects the cumulative live birth rate (CLBR) in couples with high sperm DNA fragmentation index (DFI).

DESIGN

Longitudinal cohort study.

SETTING

University-affiliated fertility clinic.

PATIENT(S)

A total of 2,713 infertile couples who underwent assisted reproductive technology treatment between 2007 and 2017 were included in the study. All in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatments (up to three fresh treatments and all associated frozen-thawed embryo transfers) offered to the couples by the public health care system were included, in total 5,422 cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was the CLBR. The secondary outcomes were the fertilization rate and the miscarriage rate. The IVF and ICSI groups were defined according to the method applied in the first treatment cycle.

RESULT(S)

In the IVF group, the CLBR values were higher for couples with normal DFI compared with those for couples with high DFI (≥20%) (48.1% vs. 41.6% for conservative CLBR estimate and 55.6% vs. 51.4% for optimal CLBR estimate after adjustment for female age, respectively). No DFI-dependent difference was seen in the ICSI group.

CONCLUSION(S)

Our results demonstrated that a high DFI predicts a statistically significantly lower CLBR if IVF and not ICSI is applied in the first cycle of assisted reproduction.

Prospective analysis over time of semen parameters in spinal cord-injured patients: Results of a pilot study

BACKGROUND

Spinal cord injury often results in erectile dysfunction and an ejaculation along with impaired semen parameters. Fertility is a major concern in spinal cord injury adult males and some fear that the delay post-spinal cord injury may negatively affect sperm quality.

OBJECTIVES

We aimed to (i) assess semen parameters over time in SCI patients according to age at spinal cord injury, time post-spinal cord injury, and the spinal cord injury level and completeness and (ii) measure markers in semen for inflammation and marker of oxidative stress to investigate their impact on sperm parameters.

MATERIALS AND METHODS

The study is a prospective, longitudinal, pilot study over 18 months. Thirty-five men with spinal cord injury from 18 to 60 years of age were enrolled. Their mean age was 29.4 ± 6.4 years. Semen retrieval was scheduled every 6 months, allowing analysis of four ejaculates, in association with measurement of granulocyte and seminal plasma elastase concentrations to assess markers in semen for inflammation and spermatozoa DNA fragmentation to assess oxidative stress.

RESULTS

Based on reference limits, a normal total sperm number, decreased motility and vitality of the spermatozoa, and increased morphological abnormalities were found. Mean round cell and granulocyte concentrations were elevated in the semen. Markers in semen for inflammation and marker of oxidative stress were elevated in several semen samples, compared to reference limits. However, neither the presence of markers in semen for inflammation or oxidative stress, the completeness or the level of the spinal cord lesion, the age or the time post-spinal cord injury had a negative impact on the semen quality over time.

DISCUSSION

There was no significant decline in semen quality in spinal cord injury patients over time within the limitations of this pilot study. Moreover, a chronic genital inflammatory status was not associated with impairment of semen quality.

CONCLUSION

The present findings are reassuring for men with spinal cord injury and could guide the management of their reproductive ability. According to these preliminary data, not all spinal cord injury patients who are able to ejaculate require systematic freezing of their spermatozoa.

Does conventional freezing affect sperm DNA fragmentation?

Objective

Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test.

Methods

In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups.

Results

There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability.

Conclusion

Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

A Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis on the clinical utility of sperm DNA fragmentation testing in specific male infertility scenarios

Background

Sperm DNA fragmentation (SDF) is recognized as a leading cause of male infertility because it can impair the paternal genome through distinct pathophysiological mechanisms. Current evidence supports SDF as a major factor in the pathophysiology of several conditions, including varicocele, unexplained infertility, assisted reproductive technology failure, and environmental lifestyle factors, although the mechanisms involved have not been fully described yet. Measurement of the levels of DNA fragmentation in semen provides valuable information on the integrity of paternal chromatin and may guide therapeutic strategies. A recently published clinical practice guideline (CPG) highlighted how to use the information provided by SDF testing in daily practice, which triggered a series of commentaries by leading infertility experts. These commentaries contained an abundance of information and conflicting views about the clinical utility of SDF testing, which underline the complex nature of SDF.

Methods

A search of papers published in response to the CPG entitled “Clinical utility of sperm DNA fragmentation testing: practice recommendations based on clinical scenarios” was performed within the Translational Andrology and Urology (TAU) website (http://tau.amegroups.com/). The start and end dates for the search were May 2017 and August 2017, respectively. Each commentary meeting our inclusion criteria was rated as “supportive without reservation”, “supportive with reservation”, “not supportive” or “neutral”. We recorded whether articles discussed either SDF characteristics as a laboratory test method or clinical scenarios, or both. Subsequently, we extracted the particulars from each commentary and utilized the ‘Strengths-Weaknesses-Opportunities-Threats’ (SWOT) analysis to understand the perceived advantages and drawbacks of SDF as a specialized sperm function method in clinical practice.

Results

Fifty-eight fertility experts from six continents and twenty-two countries contributed commentaries. Overall, participants (87.9%; n=51) were supportive of the recommendations provided by the CPG on the utility of SDF testing based on clinical scenarios. The majority of participants made explicit remarks about both the clinical scenarios and SDF assays’ characteristics. Among ‘not supportive’ and ‘supportive with reservation’ participants, 75% (n=30/40) and 77.5% (n=31/40) expressed concerns related to technical limitations of SDF testing methods and clinical utility of the test in one or more clinical scenarios discussed in the CPG, respectively. The SWOT analysis revealed that the CPG provides a reasonable evidence-based proposal for integration of SDF testing in the routine daily practice. It also uncovered gaps of knowledge and threats limiting the widespread application of SDF in everyday practice, thus allowing the identification of opportunities to further refine SDF testing and its clinical utility.

Conclusions

The understanding of the role of SDF in male infertility requires an in-depth analysis of the multifactorial pathophysiological processes and the theories involved. The SWOT analysis allowed an objective evaluation of CPG on the clinical utility of SDF testing based on clinical scenarios and its accompanying commentaries written by global experts in all possible angles. Implementation of SDF testing in the clinic may not only increase the outcome of ART but more importantly improve the health of both fathers to be and resulting offspring.