Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT04795440 |
| Other study ID # |
1802-FIVI-015-NG |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 1, 2020 |
| Est. completion date |
June 30, 2025 |
Study information
| Verified date |
March 2024 |
| Source |
Fundación IVI |
| Contact |
Nicolás Garrido Puchalt, PhD |
| Phone |
0034 963903305 |
| Email |
nicolas.garrido[@]ivirma.com |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
In patients with oligospermia in the ejaculate or previous ICSI failures if it concurs with
high DNA fragmentation, it has been hypothesized that the use of sperm obtained from the
testicle would improve the clinical results, since a source of damage to the spermatic DNA is
post-testicular in its storage in the epididymis and thus could be avoided. The clinical
information available so far is low, of low quality and all the studies present certain
limitations susceptible to improvements in further investigations before giving a definitive
answer to patients in these circumstances, about whether they should opt for testicular
biopsy or for the use of semen in the ejaculate.The intention proposed in our project, is to
demonstrate whether using testicular sperm, compared to those available in an ejaculate in
these cases, offers a clinically and statistically significant increase in chromosomally
normal embryos available that may lead to better reproductive performance of the cycles, in a
design never before done, where half of a patient's oocytes are inseminated from ejaculated
sperm and the other half from sperm obtained in the testicular biopsy.
Description:
Since its first description in 1992, intracytoplasmic sperm injection (ICSI) has been widely
used to overcome all forms of severe male factor infertility. Despite achieving acceptable
success rates with the use of abnormal sperm, studies suggest that poor sperm quality can be
detrimental to ICSI outcomes. Sperm DNA plays a critical role in normal embryonic development
because the genetic information passed on to the next generation depends on its integrity
(6-8). Deterioration of sperm DNA content has been associated with several conditions,
including lifestyle and exposure to gonadotoxins, varicocele, infections in the male
accessory glands and advanced paternal age.
Sperm DNA fragmentation (SDF) tests measure the proportion of sperm with damaged chromatin,
using probes or stains to identify DNA breaks with the aid of fluorescence microscopy, light
microscopy or flow cytometry depending on the type of method. Regardless of the analytical
method, DNA fragmentation is more common in the sperm of infertile men than fertile men.
Among couples undergoing ICSI, high SDF in the ejaculate is found in 30% of men and is
generally associated with abnormal conventional semen parameters. But this high SDF is also a
relatively common finding in infertile men with normal semen parameters, up to 20% - 40%
according to some authors. Aside from the questionable need to routinely use SDF test during
the evaluation of male infertility, recent evidence indicates that knowing the FAE can be
clinically informative in estimating the results to be obtained with assisted reproductive
techniques (ART). Although sperm with fragmented DNA can fertilize an oocyte with apparently
similar efficacy to sperm without DNA fragmentation, the negative impact of damaged paternal
chromatin is generally manifested during the development of the embryos produced, leading to
developmental blockage, implantation failure or early embryo loss, thus decreasing the
success of ART.
Among the many strategies proposed to overcome SDF in couples undergoing ART, the use of
testicular sperm instead of ejaculate in males without azoospermia has gained increased
attention, due to recent results published by various groups. The biological plausibility of
using testicular sperm for ICSI in men with high SDF in the ejaculate is based on
observations of less DNA fragmentation in sperm from the testis compared with sperm from the
ejaculate. The alteration of sperm chromatin integrity in ejaculated sperm from infertile men
may be explained, first, because chromatin compaction is still ongoing during epididymal
transit. Secondly, because excessive ROS can be generated in epididymal epithelial cells
under stress factors such as high temperatures and environmental conditions. Finally, certain
endonucleases can cleave the DNA of mature live sperm and, as a result, sperm DNA damage can
occur by different pathways, including hydroxyl radical, nitric oxide, and activation of
sperm caspases and endonucleases, thus explaining the positivity for SDF in ejaculated sperm
or sperm from infertile men.
Thus, the concept that oxidation-induced sperm chromatin damage can occur in the
post-testicular environment or in epididymal transit and storage, and that sperm recovery
with improved chromatin integrity can be achieved if the epididymis is bypassed, has led
researchers to explore the use of testicular sperm for assisted reproductive treatments.
Because of the relevance of the clinical decision to resort to the use of testicular sperm
for ICSI, especially because of the inherent risks and clinical implications of such an
intervention, the potential benefit of testicular sperm for ICSI needs to be clarified in
these cases and, thus, to determine the potential improvement that it could allow.
Our most recent work led us to examine the available evidence regarding ICSI outcomes with
testicular sperm (Testi-ICSI) and ejaculated sperm (Ejac-ICSI) among non-azoospermic
infertile men with confirmed post-testicular damage through a systematic review and
meta-analysis of the available information, where we compared: 1) ICSI outcomes of Testi-ICSI
and Ejac-ICSI among infertile men with high SDF (as defined in each study) in the ejaculate;
and 2) SDF rates among testicular sperm and ejaculates of infertile men regardless of whether
or not ICSI data were provided. Taking into account: 1) study population (history of ICSI
failure versus no prior history of ICSI failure); 2) semen analysis profile of participants
(oligozoospermia vs. normozoospermia); 3) method of SDF testing; and 4) method of sperm
retrieval, and finding conflicting evidence regarding the use of Testi-ICSI in nonazoospermic
men and the inherent risks of complications after sperm retrieval, it is necessary to clarify
whether any particular male infertility population may derive benefit from this intervention.
Five studies compared SDF levels between ejaculated and testicular sperm for 143 patients who
served as their own controls. The mean SDF rates in testicular and ejaculated sperm were 8.9
± 5.1% and 33.4 ± 12.8% (P <.0001), respectively. Overall, the results indicated that SDF
rates were lower in testicular sperm than in ejaculate with the mean difference being 24.58%
(95% CI 32.53 to 16.64); I2 = 92%; P <.001. To assess heterogeneity, we performed a subgroup
analysis according to the method used to assess SDF. Four studies used TUNEL assay and one
study, the SCD test. With TUNEL, pooled results indicated lower rates of SDF in testis sperm
than in ejaculates, with a mean difference of 19.78% (95% CI 22.35% to 17.21%; I2 = 15%; P
<.001). In the only study using the SCD method, the mean difference was 32.4% (95% CI 34.85%
to 29.95%; P <.001) in favor of testicular sperm.Regarding clinical pregnancy rates (CPR),
four studies provided CPRs for 379 Testi-ICSI and Ejac-ICSI embryo transfers in patients with
high AEF. The results indicated that CPRs were higher with Testi-ICSI than with Ejac-ICSI,
being 50.0% and 29.4% (P <.001), respectively, with an OR of 2.42 (95% CI, 1.57 to 3.73; I2 =
34%; P <.001). Subgroup analysis by study population and semen profile revealed that the
observed pooled effect size was larger for failed ICSI in studies with normozoospermic men,
with greater improvement in Testi-ICSI observed in couples with no history of ICSI failure
and oligozoospermic men, although differences between subgroups were not statistically
significant. The consistency in the direction of effect across all studies increased
confidence in the results of a positive outcome effect of Testi-ICSI in CPR.When considering
miscarriage rates in four studies between 151 Testi-ICSI and Ejac-ICSI clinical pregnancies
in patients with high AEF. The results indicated that for miscarriage the rates were reduced
with Testi-ICSI compared with Ejac-ICSI, being 9.4% and 29.1% (P<.002), respectively, with an
OR of 0.28 (95% CI 0.11 to 0.68; P = 0.005; I2 = 11%). The observed pooled effect size was
larger for studies involving couples with a history of ICSI failure and normozoospermia than
without a history of ICSI failure and oligozoospermia, although the difference between
subgroups was not statistically significant. Regarding live newborn rates (LBR), two studies
reported LBRs for 272 embryo transfers of Testi-ICSI and Ejac-ICSI in patients with high SDF.
The results indicated that LBRs were higher with Testi-ICSI than with Ejac-ICSI, being 46.9%
and 25.6% (P <.001), respectively, with an OR of 2.58 (95% CI 1.54-4.35; I2 = 0, P <.001).
These results were consistent in suggesting a positive effect of Testi-ICSI on TRNV among men
with high SDF.
Most of the studies included in our meta-analysis used TUNEL assay, which has been considered
the most accurate method for predicting pregnancy in ART, with an area under the receiver
operating characteristic curve of 0.71 (95% CI 0.66-0.76). Four of the studies applied the
cutoff value of 30% sperm with fragmented DNA in pure semen to discriminate between normal
and high SDF samples (34, 37, 40, 41), and the remaining studies used thresholds of 29%, 15%,
and 7%. Notably, three of the four studies providing Testi-ICSI and Ejac-ICSI data agree on
the cutoff value used to classify patients with high SDF. Therefore, despite the controversy
as to which sperm DNA test and threshold values should be adopted clinically, our results
suggest that Testi-ICSI is beneficial when SDF values exceed 29%. Many conditions associated
with SDF may be correctable, including varicocele, lifestyle factors, and genital infections,
and potentially enable or improve the possibility of natural conception or allow the use of
ejaculated sperm for ICSI. In other cases, testicular biopsy may be an option to
consider.Finally, despite having low overall DNA damage, testicular sperm may have higher
rates of aneuploidy. In a recent paper, SDF rates were almost three times lower in testicular
sperm than in ejaculated counterparts (14.9± 5.0% vs. 40.6± 14.8%; P<.05), but aneuploidy
rates for chromosomes 13, 18, 21, X, and Y were higher in the former (12.4%± 3.7% vs. 5.7%±
1.2%; P<.05). Nevertheless, the data do not show an increased risk of malformations in
offspring generated from ICSI cycles using testicular sperm, but continued monitoring is
required until the safety of this strategy is confirmed.
Given that the quality and number of available studies on Test-ICSI in the context of high
SDF is still limited, further studies are required, particularly randomized controlled trials
that evaluate different aspects still unresolved in previous work. For example, none of the
studies genetically analyzed the available embryos, nor their quality, let alone the
cumulative rates obtained with frozen embryos, and subsequently in subsequent thawed cycles.
The calculation of the results, estimating embryo transfer as the denominator, is introducing
a negative bias, that is, unintentionally hiding a greater effect of the intervention, by
selecting among the available embryos those with better characteristics, and taking into
account only the contribution of these (thus making the differences between the groups to be
compared smaller). Any intervention carried out in relation to spermatozoa must take this
limitation into account, since it affects the entire embryo cohort, not just the embryos
transferred, and thus the magnitude of the effect of the intervention is not adequately
assessed. This would improve the adequacy of the effect size estimate and allow a better
judgment of the clinical significance of our findings.
In addition, the study of semen samples after freezing and thawing/capacitation allows
control of iatrogenic damage caused by laboratory manipulation, which had not been previously
considered, and the control of the female contributing factor to reproductive success that is
missing in previous studies would also be considered in our work, by statistically
controlling for potentially influential variables. For the time being, our meta-analysis
indicates that FAE rates are lower in testis sperm than in ejaculated sperm and clinical
outcomes are higher for men with confirmed post-testicular SDF when Testi-ICSI rather than
Ejac-ICSI is used. Therefore, the existing literature supports the recommendation to use
Testi-ICSI in select groups of men with confirmed post-testicular SDF in ejaculate. Given the
generally low to moderate quality of the studies reviewed and the potential risks associated
with sperm retrieval, the need for further confirmatory evidence using an alternative
prospective approach is warranted. At present, Testi-ICSI should be reserved for men with
substantial AEF undergoing ART, particularly those who have experienced repeated ICSI
failures and when measures to correct other underlying factors causing SDF have failed.
