Paternal influence of sperm DNA integrity on early embryonic development

Reproductive outcomes in patients with high levels of sperm DNA fragmentation using testicular sperm for intracytoplasmic injection: a retrospective analysis

This study aims to compare the embryological and clinical parameters of intracytoplasmic sperm injection (ICSI) cycles using testicular versus ejaculated sperm in male patients with elevated sperm DNA fragmentation (SDF). A total of 73 ICSI cycles were examined in couples where the male partner exhibited high levels of SDF. ICSI was performed using either ejaculated or testicular sperm. The primary outcomes were rates of blastocyst formation, high-quality embryo development, and clinical pregnancy. The DNA fragmentation index (DFI) for testicular sperm (16.81 ± 17.51) was significantly lower than that of ejaculated sperm (56.96 ± 17.56). While the blastocyst formation rate was significantly higher in the testicular sperm group compared to the ejaculated sperm group, no statistically significant differences were noted in fertilization rate (72.15% vs. 77.23%), rate of high-quality embryo formation (47.17% vs. 46.53%), clinical pregnancy (50% vs. 56.52%), Cumulative pregnancy (70.2% vs. 55.6%), or live birth rate (43.75% vs.43.48%). Testicular spermatozoa have no additional advantage over ejaculated spermatozoa except for blastocyst quality in patients with high SDF, the use of testicular spermatozoa for the first ICSI cycle in male infertility patients with high SDF should be undertaken after much consideration at present.

Advances in microfluidic technology for sperm screening and in vitro fertilization

About 18% of reproductive-age adults worldwide are affected by infertility. In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are widely used assisted reproductive technologies (ARTs) aimed at improving clinical outcomes. Efficient and noninvasive selection and isolation of highly motile sperm with intact DNA are essential for the success of IVF and ICSI and can potentially impact the therapeutic efficacy and the health of the offspring. Compared to traditional methods, microfluidic technology offers significant advantages such as low sample consumption, high efficiency, minimal damage, high integration, similar microenvironment, and high automation, providing a new platform for ARTs. Here, we review the current situation of microfluidic technology in the field of sperm motility screening and evaluation and IVF research. First, we focus on the working principle, structural design, and screening results of sperm selection microfluidic platforms. We then highlight how the multiple steps of the IVF process can be facilitated and integrated into a microfluidic chip, including oocyte capture, sperm collection and isolation, sperm sorting, fertilization, and embryo culture. Ultimately, we summarize how microfluidics can complement and optimize current sperm sorting and IVF protocols, and challenges and possible solutions are discussed.

Bibliometric and visual analysis on oxidative stress in gynecological and reproductive diseases: A systematic review

BACKGROUND

The imbalance between the generation and elimination of reactive oxygen species (ROS) is defined as oxidative stress (OS). Elevated levels of OS are implicated in various diseases, especially in gynecological and reproductive disorders. The abundance of recent literature makes it challenging to assimilate all available information. This bibliometric analysis seeks to depict the research landscape of OS in gynecological and reproductive diseases and to identify future hotspots and trends.

METHODS

The Web of Science Core Collection served as the source for articles related to OS in gynecological and reproductive diseases. CtieSpace and VOSviewer software were utilized to analyzed countries/regions, institutions, journals, authors, and keywords of all eligible articles.

RESULTS

A total of 1423 articles were included. There was a gradual increase in the number of publications in this field. The USA maintained the highest number of publications, with 372 articles. Cleveland Clinic was the leading institution in terms of publication volume, contributing 67 articles. In total, 6925 authors were identified. Agarwal A as the most frequently co-cited author, received 812 citations across 43 publications. The predominant clusters included "placenta," "polycystic ovary syndrome," "male infertility," and "oocyte quality." Notably, "oocyte quality'" was identified as a current key research topic.

CONCLUSION

There was an uptrend in the number of articles addressing OS in gynecological and reproductive diseases. However, international collaboration and exchange were limited. The topic of male infertility had remained a consistent area of interest, and research on oocyte quality is poised to become a potential focal point in the future.

Establishment and validation of a nomogram for subsequent first-cycle live births in patients diagnosed with recurrent implantation failure: a population-based analysis

Background

The inability of patients with recurrent implantation failure (RIF) to achieve pregnancy and a live birth after multiple high-quality embryo transfer treatments has been recognized as a major obstacle to successful application of artificial reproductive technologies. The objective of this study was to establish and validate a nomogram for prediction of subsequent first-cycle live births to guide clinical practice in patients diagnosed with RIF.

Methods

A total of 538 patients who underwent in vitro fertilization/intracytoplasmic sperm injection treatment and were first diagnosed with RIF at the Reproductive Center of the First Affiliated Hospital of Xinjiang Medical University between January 2017 and December 2020 were enrolled. The patients were randomly divided into a training cohort (n=408) and a validation set (n=175) in a ratio of 7:3. A nomogram model was constructed using the training set based on the results of univariate and multivariate logistic regression analyses and validated in the validation set.

Results

Age, body mass index, duration of RIF, endometrial thickness, type of embryo transferred, and number of previous biochemical pregnancies were included in the nomogram for prediction of subsequent first-cycle live births in patients diagnosed with RIF. Analysis of the area under the receiver-operating characteristic curve, calibration plots, and decision curve analysis showed that our predictive model for live births had excellent performance.

Conclusion

We have developed and validated a novel predictive model that estimates a woman's chances of having a live birth after a diagnosis of RIF and provides clinicians with a personalized clinical decision-making tool.

Germline cell de novo mutations and potential effects of inflammation on germline cell genome stability

Uncontrolled pathogenic genome mutations in germline cells might impair adult fertility, lead to birth defects or even affect the adaptability of a species. Understanding the sources of DNA damage, as well as the features of damage response in germline cells are the overarching tasks to reduce the mutations in germline cells. With the accumulation of human genome data and genetic reports, genome variants formed in germline cells are being extensively explored. However, the sources of DNA damage, the damage repair mechanisms, and the effects of DNA damage or mutations on the development of germline cells are still unclear. Besides exogenous triggers of DNA damage such as irradiation and genotoxic chemicals, endogenous exposure to inflammation may also contribute to the genome instability of germline cells. In this review, we summarized the features of de novo mutations and the specific DNA damage responses in germline cells and explored the possible roles of inflammation on the genome stability of germline cells.

High sperm DNA fragmentation increased embryo aneuploidy rate in patients undergoing preimplantation genetic testing

RESEARCH QUESTION

Is high sperm DNA fragmentation (SDF) associated with a high embryonic aneuploidy rate in patients undergoing intracytoplasmic sperm injection (ICSI)-preimplantation genetic testing (PGT)?

DESIGN

This was a retrospective study of 426 couples with normal karyotypes undergoing ICSI-PGT at the authors' centre from March 2017 to March 2021. SDF was assessed using the sperm chromatin structure assay. The population was divided into low and high SDF groups according to cut-off values found by the receiver operating characteristic (ROC) curve. A 1:1 ratio propensity score matching (PSM) method was used to control for potential confounding factors, and a generalized linear mixed model was established to evaluate the relationship between SDF and the embryonic aneuploidy rate.

RESULTS

The ROC curve indicated a threshold of 30%. In total, 132 couples were included after PSM, and the high SDF group (>30%) had significantly higher SDF (40.74% ± 9.78% versus 15.54% ± 7.86%, P < 0.001) and a higher embryo aneuploidy rate (69.36% versus 53.96%, P < 0.001) compared with the low SDF group (≤30%). The two pronuclear fertilization rate, cleavage rate, rate of high-quality embryos at day 3 rate, blastocyst rate, biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, caesarean section rate, preterm birth rate, singleton rate and low birthweight rate were similar in both groups (P > 0.05). After PSM, SDF > 30% was significantly correlated with an increased embryo aneuploidy rate after adjusting for all confounding variables (adjusted odds ratio 1.70, 95% CI 1.00-2.88, P = 0.049).

CONCLUSIONS

SDF > 30% was associated with an increased embryo aneuploidy rate in couples with normal karyotypes undergoing PGT, but did not affect embryonic and clinical outcomes after transfer of euploid embryos.

Epigenetic aging of mammalian gametes

The process of aging refers to physiological changes that occur to an organism as time progresses and involves changes to DNA, proteins, metabolism, cells, and organs. Like the rest of the cells in the body, gametes age, and it is well established that there is a decline in reproductive capabilities in females and males with aging. One of the major pathways known to be involved in aging is epigenetic changes. The epigenome is the multitude of chemical modifications performed on DNA and chromatin that affect the ability of chromatin to be transcribed. In this review, we explore the effects of aging on female and male gametes with a focus on the epigenetic changes that occur in gametes throughout aging. Quality decline in oocytes occurs at a relatively early age. Epigenetic changes constitute an important part of oocyte aging. DNA methylation is reduced with age, along with reduced expression of DNA methyltransferases (DNMTs). Histone deacetylases (HDAC) expression is also reduced, and a loss of heterochromatin marks occurs with age. As a consequence of heterochromatin loss, retrotransposon expression is elevated, and aged oocytes suffer from DNA damage. In sperm, aging affects sperm number, motility and fecundity, and epigenetic changes may constitute a part of this process. 5 methyl-cytosine (5mC) methylation is elevated in sperm from aged men, but methylation on Long interspersed nuclear elements (LINE) elements is reduced. Di and trimethylation of histone 3 lysine 9 (H3K9me2/3) is reduced in sperm from aged men and trimethylation of histone 3 lysine 27 (H3K27me3) is elevated. The protamine makeup of sperm from aged men is also changed, with reduced protamine expression and a misbalanced ratio between protamine proteins protamine P1 and protamine P2. The study of epigenetic reproductive aging is recently gaining interest. The current status of the field suggests that many aspects of gamete epigenetic aging are still open for investigation. The clinical applications of these investigations have far-reaching consequences for fertility and sociological human behavior.

Nuclear sperm integrity and ICSI prognosis in Tunisian patients with MMAF syndrome (multiple morphological abnormalities of the sperm flagella)

Multiple Morphological Abnormalities of the Sperm Flagella (MMAF) is a severe form of teratozoospermia associated with several sperm flagellar abnormalities. The study included 52 patients with MMAF syndrome and a control group of 25 fertile men. The impact of nuclear sperm quality on intracytoplasmic sperm injection (ICSI) results was studied in 20 couples. TUNEL assay was used to assess sperm DNA fragmentation and aniline-blue staining was used to assess chromatin condensation. To investigate chromosomal meiotic segregation, we used fluorescence in situ hybridization (FISH). Semen morphology analysis revealed a mosaic of multiple flagella morphological abnormalities, including 46.73% short flagella, 16.22% bent flagella, 22.07% coiled flagella, and 10.90% absent flagella, all of which were associated with a high percentage of sperm head abnormalities. The mean DNA fragmentation index was substantially higher in patients compared to controls (p = 0.001), whereas the rate of aniline blue-reacted spermatozoa was not significantly different. There was a significant difference in aneuploidy frequencies between the two groups (p < 0.05). Infertile males with MMAF syndrome had lower sperm nuclear quality, which affected ICSI results. As a result, better sperm selection procedures are being employed to increase the success rate of assisted reproductive technologies (ART).

Sperm chromatin structure assay (SCSA®) and flow cytometry-assisted TUNEL assay provide a concordant assessment of sperm DNA fragmentation as a function of age in a large cohort of approximately 10,000 patients

BACKGROUND

Sperm DNA integrity is increasingly seen as a critical characteristic determining reproductive success, both in natural reproduction and in assisted reproductive technologies (ART). Despite this awareness, sperm DNA and nuclear integrity tests are still not part of routine examinations for either infertile men or fertile men wishing to assess their reproductive capacity. This is not due to the unavailability of DNA and sperm nuclear integrity tests. On the contrary, several relevant but distinct tests are available and have been used in many clinical trials, which has led to conflicting results and confusion. The reasons for this are mainly the lack of standardization between different clinics and between the tests themselves. In addition, the small number of samples analyzed in these trials has often weakened the value of the analyses performed. In the present work, we used a large cohort of semen samples, covering a wide age range, which were simultaneously evaluated for sperm DNA fragmentation (SDF) using two of the most frequently used SDF assays, namely the TUNEL assay and the sperm chromatin structure assay (SCSA®). At the same time, as standard seminal parameters (sperm motility, sperm morphology, sperm count) were available for these samples, correlations between age, SDF and conventional seminal parameters were analyzed.

RESULTS

We show that the SCSA® and TUNEL assessments of SDF produce concordant data. However, the SDF assessed by TUNEL is systematically lower than that assessed by SCSA®. Regardless of the test used, the SDF increases steadily during aging, while the HDS parameter (High DNA stainability assessed via SCSA®) remains unchanged. In the cohort analyzed, conventional sperm parameters do not seem to discriminate with aging. Only sperm volume and motility were significantly lower in the oldest age group analyzed [50-59 years of age].

CONCLUSIONS

In the large cohort analyzed, SDF is an age-dependent parameter, increasing linearly with aging. The SCSA® assessment of SDF and the flow cytometry-assisted TUNEL assessment are well correlated, although TUNEL is less sensitive than SCSA®. This difference in sensitivity should be taken into account in the final assessment of the true level of fragmentation of the sperm nucleus of a given sample. The classical sperm parameters (motility, morphology, sperm count) do not change dramatically with age, making them inadequate to assess the fertility potential of an individual.

Low levels of mouse sperm chromatin fragmentation delay embryo development

We previously demonstrated that MnCl2 induces double-stranded DNA breaks in sperm in a process that we term as sperm chromatin fragmentation. Here, we tested if the levels of double-stranded DNA breaks were corelated to the concentration of MnCl2, and we compared this to another agent that causes single-stranded DNA breaks, H2O2. We found that both methods have the advantage of inducing DNA breaks in a concentration-dependent manner. Mouse sperm were treated with varying concentrations of either H2O2 or MnCl2, and the DNA damage was assessed by pulse-field gel electrophoresis, and the alkaline and neutral comet assays. Oocytes were injected with either treated sperm and the resulting embryos analyzed with an embryoscope to detect subtle changes in embryonic development. We confirmed that H2O2 treatment induced primarily single-stranded DNA breaks and MnCl2 induced primarily double-stranded DNA breaks, indicating different mechanisms of damage. These sperm were injected into oocytes, and the development of the resulting embryos followed with an embryoscope equipped with time lapse recording. We found that aberrations in early embryonic development by day 2 with even the lowest levels of DNA damage and that the levels of embryonic aberrations correlated to the concentration of either H2O2 or MnCl2. Low levels of H2O2 caused significantly more aberrations in embryonic development than low levels of MnCl2 even though the levels of DNA damage as measured by comet assays were similar. These data demonstrate that even low levels of sperm DNA damage cause delays and arrests in embryonic development.

Sperm Chromatin Status and DNA Fragmentation in Mouse Species with Divergent Mating Systems

Sperm DNA integrity and chromatin status serve as pivotal indicators of sperm quality, given their intricate link to sperm function, embryo development, and overall fertility. Defects in chromatin compaction, which are often associated with compromised protamine content, can lead to damaged DNA strands. In this study, the chromatin status and possible correlation with DNA damage was assessed in males of three mouse species: Mus musculus, M. spretus, and M. spicilegus. We employed various staining methods, including aniline blue, methylene blue (Diff-Quik), toluidine blue, and chromomycin A3, to assess chromatin compaction in cauda epididymal sperm. Samples were also analyzed by the sperm chromatin structure assay (SCSA) to estimate DNA fragmentation (%tDFI, %HDS). Analyses were carried out on freshly collected sperm and cells incubated for 3 h in a HEPES-buffered modified Tyrode's medium simulating conditions of the female reproductive tract. Notably, the analysis of chromatin status yielded minimal abnormal values across all three species employing diverse methodologies. SCSA analyses revealed distinct variations in %tDFI between species. Following sperm incubation, the percentages of sperm stained with methylene blue exhibited differences among the species and were significantly correlated to the DNA fragmentation index. HDS demonstrated correlations with the percentages of sperm stained by aniline blue, methylene blue, and chromomycin A3. Overall, chromatin compaction was high across all species, with limited differences among them. The relationship between chromatin status and DNA integrity appeared to be related to levels of sperm competition among species.

The effect of sperm DNA fragmentation on ICSI outcomes depending on oocyte quality

BACKGROUND

Sperm deoxyribonucleic acid (DNA) fragmentation is commonly encountered in spermatozoa, and the oocyte assumes responsibility for repairing sperm DNA fragmentation during the oocyte-embryo transition.

OBJECTIVES

This study aimed to investigate whether the effect of sperm DNA fragmentation on intracytoplasmic sperm injection outcomes depends on the incidence of oocyte dimorphisms.

MATERIALS AND METHODS

For the present cohort, 2942 fertilized oocytes from 525 patients submitted to intracytoplasmic sperm injection cycles were assessed. The present study was conducted in a private in vitro fertilization center affiliated to a university from June 2016 to July 2019. Semen samples were divided into the following two groups depending on the sperm DNA fragmentation index: a low fragmentation index group (<30% sperm DNA fragmentation, n = 1468) and a high fragmentation index group (≥30% sperm DNA fragmentation, n = 486). In addition, mature oocytes were examined before sperm injection, and intracytoplasmic and extracytoplasmic defects were recorded. The effect of the sperm DNA fragmentation index on laboratory and clinical intracytoplasmic sperm injection outcomes (depending on the presence of oocyte defects) was evaluated.

RESULTS

Significant increases in the rates of fertilization, high-quality embryo, implantation, and pregnancy were noted for cycles with <30% sperm DNA fragmentation than cycles with ≥30% sperm DNA fragmentation (regardless of the presence of oocyte dimorphisms). The presence of dimorphisms significantly impacted laboratory and clinical outcomes. The lowest fertilization and high-quality embryo rates were observed when a high sperm DNA fragmentation index was associated with the presence of dark cytoplasm, vacuoles, resistant membrane, and non-resistant membrane. The lowest implantation and pregnancy rates were observed when a high sperm DNA fragmentation index was associated with the presence of vacuoles, defective perivitelline space, and fragmented polar body. The effect of sperm DNA fragmentation on miscarriage rates was significantly influenced by the presence of centrally located cytoplasmic granulation, a defective perivitelline space and non-resistant membrane.

CONCLUSION

A high sperm DNA fragmentation index increases the likelihood of miscarriage in intracytoplasmic sperm injection cycles, an effect that may potentially be magnified by the presence of oocyte dysmorphisms.

An intracellular, non-oxidative factor activates in vitro chromatin fragmentation in pig sperm

BACKGROUND

In vitro incubation of epididymal and vas deferens sperm with Mn2+ induces Sperm Chromatin Fragmentation (SCF), a mechanism that causes double-stranded breaks in toroid-linker regions (TLRs). Whether this mechanism, thought to require the participation of topoisomerases and/or DNAses and thus far only described in epididymal mouse sperm, can be triggered in ejaculated sperm is yet to be elucidated. The current study aimed to determine if exposure of pig ejaculated sperm to divalent ions (Mn2+ and Mg2+) activates SCF, and whether this has any impact on sperm function and survival. For this purpose, sperm DNA integrity was evaluated through the Comet assay and Pulsed Field Gel Electrophoresis (PFGE); sperm motility and agglutination were assessed with computer assisted sperm analysis (CASA); and sperm viability and levels of total reactive oxygen species (ROS) and superoxides were determined through flow cytometry.

RESULTS

Incubation with Mn2+/Ca2+ activated SCF in a dose-dependent (P < 0.05) albeit not time-dependent manner (P > 0.05); in contrast, Mg2+/Ca2+ only triggered SCF at high concentrations (50 mM). The PFGE revealed that, when activated by Mn2+/Ca2+ or Mg2+/Ca2+, SCF generated DNA fragments of 33-194 Kb, compatible with the size of one or multiple toroids. Besides, Mn2+/Ca2+ affected sperm motility in a dose-dependent manner (P < 0.05), whereas Mg2+/Ca2+ only impaired this variable at high concentrations (P < 0.05). While this effect on motility was concomitant with an increase of agglutination, neither viability nor ROS levels were affected by Mn2+/Ca2+ or Mg2+/Ca2+ treatments.

CONCLUSION

Mn2+/Ca2+ and Mn2+/Ca2+ were observed to induce SCF in ejaculated sperm, resulting in DNA cleavage at TLRs. The activation of this mechanism by an intracellular, non-oxidative factor sheds light on the events taking place during sperm cell death.

Transition nuclear protein 1 as a novel biomarker in patients with fertilization failure

OBJECTIVE

Although intracytoplasmic sperm injection (ICSI) is a way to deal with in vitro fertilization failure, 3% of couples still experience repeated fertilization failure after attempted ICSI, despite having sperm within normal parameters. These patients are a challenging group whose sperm cannot fertilize the egg during ICSI. Unfortunately, no test can predict the risk of fertilization failure. Phospholipase C zeta (PLCζ) and transition nuclear proteins (TNPs) are essential factors for chromatin packaging during sperm maturation. This study aimed to assess PLCζ1 and TNP1 expression in the sperm of patients with fertilization failure and the correlations among the DNA fragmentation index, PLCζ1 and TNP1 gene and protein expression, and the risk of fertilization failure.

METHODS

In this study, 12 infertile couples with low fertilization rates (<25%) and complete failure of fertilization in their prior ICSI cycles despite normal sperm parameters were chosen as the case group. Fifteen individuals who underwent ICSI for the first time served as the control group. After sperm analysis and DNA fragmentation assays, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to compare the gene and protein expression of PLCζ and TNP1 in both groups.

RESULTS

DNA fragmentation was significantly higher in the fertilization failure group. The qRT-PCR and Western blot results demonstrated significantly lower PLCζ and TNP1 gene and protein expression in these patients than in controls.

CONCLUSION

The present study showed that fertilization failure in normozoospermic men was probably due to deficient DNA packaging and expression of TNP1.

The effect of sperm DNA fragmentation on in vitro fertilization outcomes of unexplained infertility

BACKGROUND

Infertility is caused by heterogeneous risks, but most of them are unexplained. The sperm DNA Fragmentation Index (DFI) was increasingly acknowledged as a parameter for the evaluation of male infertility. This study aimed to investigate the association between sperm DFI and laboratory and clinical outcomes in a population with unexplained infertility.

METHODS

The clinical data of an infertile population was collected for the selection of reproductive patients with unexplained infertility. The authors classified the patients with normal sperm parameters in a control group (DFI < 25%) and an observation group (DFI ≥ 25%) and compared the difference in basal characteristics, laboratory, and clinical outcomes between the two groups. The authors conducted a correlation analysis to examine the relationship between DFI and the number of D3 good-quality embryos, as well as the clinical pregnancy rate and live birth rate. A total of 176 cases were enrolled in the retrospective study.

RESULTS

The observation group (n = 88) showed advanced male age, lower sperm concentration, progressive motility, and morphology assessment than the control group. In addition, lower No. of D3 good-quality embryos, clinical pregnancy rate, and the live birth rate were shown in the observation group. A negative correlation between the DFI and No. of D3 good-quality embryos (rs = -0.347, p < 0.001) or live birth rate (rs = -0.185, p = 0.028) was shown.

CONCLUSIONS

Sperm DFI was a good indicator for the prediction of D3 good-quality embryos in unexplained infertility couples, but it did not provide sufficient information regarding clinical pregnancy outcome but live pregnancy outcome.

The Sperm DNA Fragmentation Assay with SDF Level Less Than 15% Provides a Useful Prediction for Clinical Pregnancy and Live Birth for Women Aged under 40 Years

This retrospective cohort study was conducted on 1148 males who presented along with their partners for infertility management at the PIVET Medical Centre between 2013 and 2022 and had a sperm DNA fragmentation (SDF) assay performed by Halosperm, thereafter participating in 1600 assisted reproductive technology (ART) cycles utilising one of three modalities, namely, IVF-Only, ICSI-Only or IVF-ICSI Split cycles. The outcomes from the ART cycles were then analysed as two groups based on SDF levels <15% and ≥15%. The study showed the unadjusted fertilization rates were not different between the groups, neither across the four female age ranges. However, when the fertilization rates were adjusted for the mature oocytes (metaphase-II oocytes), there was a highly significant difference in fertilization rates in favour of the group with SDF levels < 15% where the women were in the younger age grouping of <35 years (78.4% vs. 73.0%; p < 0.0001). Overall, there was no difference in the rates of blastocyst development nor clinical pregnancy rates between the two SDF groups, but there was a significantly higher pregnancy rate for the younger women (<35 years) with the group of SDF level < 15% (44.1% vs. 37.4%; p = 0.04). Similarly, there was no difference in the miscarriage rates overall with respect to SDF groups, and no clear picture could be deciphered among the women's age groups. With respect to cumulative live births, this reflected the pregnancy rates with no overall difference between the two SDF groups, but there was a significantly higher cumulative live birth rate for women <35 years where the SDF level was <15% (38.6% vs. 28.6%; p < 0.01). Among the three modalities, the highest cumulative live birth rate occurred within the group with SDF level < 15%, being highest with the IVF mode, particularly for women aged <40 years (43.0% vs. 37.7% for IVF-ICSI Split and 27.9% for ICSI; p = 0.0002), noting that the IVF case numbers were disproportionately low.

Sperm deoxyribonucleic acid fragmentation index at the time of intracytoplasmic sperm injection and standard in vitro fertilization is correlated with lower fertilization but not with blastocyst genetic diagnosis

Objective

To determine the effects of sperm deoxyribonucleic acid (DNA) fragmentation at the time of fertilization on in vitro fertilization (IVF) outcomes and genetic diagnosis using next generation sequencing.

Design

Prospective double-blinded study.

Setting

Private Clinic.

Patients

Couples (n = 150).

Intervention

In vitro fertilization with preimplantation genetic testing for aneuploidy and sperm DNA fragmentation assay, as in sperm chromatin structure assay the day of retrieval.

Main Outcome Measures

Laboratory outcomes are listed in the results section. Statistical analysis was performed using JMP, XYLSTAT, and STATA version 15.

Results

The sperm DNA fragmentation index (DFI) in the neat ejaculate did not predict fertilization rate, quality, blastulation, or genetic diagnosis. No statistically significant results were obtained comparing <15% with >15%, <20% with >20%, <30% with >30% except for DFI. No statistically significant differences in oocyte source age or male age were observed. No statistically significant differences comparing <15% with >15%, <20% with >20%, <30% with >30% DFI at the time of standard IVF or intracytoplasmic sperm injection (ICSI) were observed for % euploid, aneuploid, mosaic, blastulation, biopsied, or D5/total biopsied. The DFI of >15% had more good quality D3 embryos than the <15% group, as did the >20% group compared with the <20% group. The ICSI fertilization was significantly higher in all 3 lower percentage groups compared with the higher counterpart. Standard IVF had significantly more blastocysts/fertilized suitable for biopsy and more D5/total number biopsied than ICSI embryos despite no difference in DFI.

Conclusions

The DFI at fertilization is correlated with decreased fertilization for ICSI and IVF.

Impact of Advanced Paternal Age on Fertility and Risks of Genetic Disorders in Offspring

The average age of fathers at first pregnancy has risen significantly over the last decade owing to various variables, including a longer life expectancy, more access to contraception, later marriage, and other factors. As has been proven in several studies, women over 35 years of age have an increased risk of infertility, pregnancy problems, spontaneous abortion, congenital malformations, and postnatal issues. There are varying opinions on whether a father's age affects the quality of his sperm or his ability to father a child. First, there is no single accepted definition of old age in a father. Second, much research has reported contradictory findings in the literature, particularly concerning the most frequently examined criteria. Increasing evidence suggests that the father's age contributes to his offspring's higher vulnerability to inheritable diseases. Our comprehensive literature evaluation shows a direct correlation between paternal age and decreased sperm quality and testicular function. Genetic abnormalities, such as DNA mutations and chromosomal aneuploidies, and epigenetic modifications, such as the silencing of essential genes, have all been linked to the father's advancing years. Paternal age has been shown to affect reproductive and fertility outcomes, such as the success rate of in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), and premature birth rate. Several diseases, including autism, schizophrenia, bipolar disorders, and paediatric leukaemia, have been linked to the father's advanced years. Therefore, informing infertile couples of the alarming correlations between older fathers and a rise in their offspring's diseases is crucial, so that they can be effectively guided through their reproductive years.

Separating the chaff from the wheat: antibody-based removal of DNA-fragmented sperm

STUDY QUESTION

Is it possible to remove sperm with damaged DNA from a semen sample?

SUMMARY ANSWER

By using immunomagnetic cell sorting that targets the sperm head-bound epididymal sperm-binding protein 1 (ELSPBP1), it was possible to produce an ELSPBP1(-) sperm fraction characterized by consistently lower levels of sperm DNA fragmentation (SDF).

WHAT IS KNOWN ALREADY

In bovines, ELSPBP1 is bound to dead spermatozoa. Human ejaculates with high SDF have increased detected levels of sperm ELSPBP1 when compared to ejaculates with low native SDF.

STUDY DESIGN, SIZE, DURATION

We recruited 267 patients who were referred to the clinic for conjugal infertility. After applying exclusion criteria, such as fever within 90 days of the study, history of systemic diseases, alterations or surgical interventions to the genital tract and use of cigarette or drugs, a total of 133 patients were included. A total of 52 samples were used for the evaluation of sperm ELSPBP1 levels (Sub-study 1), 41 samples for determination of ELSPBP1 location in human sperm (Sub-study 2), and 40 samples for immunomagnetic cell sorting targeting ELSPBP1, to produce ELSPBP1(-) (without ELSPBP1) and ELSPBP1(+) (with ELSPBP1) fractions (Sub-study 3). Samples were collected between July 2016 and September 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In Sub-study 1, sperm ELSPBP1 levels were assessed by western blotting. For Sub-study 2, ELSPBP1 was localized in sperm by immunocytochemistry. Finally, for Sub-study 3, sperm were selected based on incubation of semen samples with antibody-coated magnetic microspheres targeting ELSPBP1. Two fractions were produced (with or without ELSPBP1), and these sub-populations were submitted to an alkaline Comet assay for determination of SDF.

MAIN RESULTS AND THE ROLE OF CHANCE

Men with high SDF presented higher sperm ELSPBP1 levels when compared to the control group (low SDF), while no difference between groups was observed in seminal plasma. ELSPBP1 was located in the head region of human sperm. The ELSPBP1(+) fractions presented high and variable levels of SDF, while their paired ELSPBP(-) fractions presented consistently low SDF.

LIMITATIONS, REASONS FOR CAUTION

This work did not validate the levels of ELSPBP1 in other functional alterations of sperm, such as acrosome integrity or mitochondrial activity. Moreover, this is still a pre-clinical study, intended to demonstrate proof-of-concept that ELSPBP1 selects sperm with low DNA fragmentation; further investigation is warranted to demonstrate safety for use in ART. Sperm fractions were not assessed for sperm vitality. A clinical trial is still necessary for these findings to be extrapolated to outcomes in ART.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrate that ELSPBP1 is associated with sperm with higher levels of DNA fragmentation. The finding that the sperm membrane can reflect alterations in DNA integrity could give rise to a novel molecular method for sperm preparation prior to use of assisted reproductive procedures. Moreover, the detection of sperm-bound ELSPBP1 could serve as an indirect method for the determination of DNA fragmentation.

STUDY FUNDING/COMPETING INTEREST(S)

L.B.B. was a recipient of a Ph.D. scholarship from the Sao Paulo Research Foundation-FAPESP (process number 2016/05487-3). R.P.B. is a recipient of a Scientific Productivity scholarship from the Brazilian National Council for Scientific and Technological Development-CNPq (process number 306705/2017-6). The authors have no conflict of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Sperm DNA fragmentation testing in clinical management of reproductive medicine

Background

Approximately 8%-12% of couples worldwide face infertility, with infertility of individuals assigned male at birth (AMAB) contributing to at least 50% of cases. Conventional semen analysis commonly used to detect sperm abnormalities is insufficient, as 30% of AMAB patients experiencing infertility show normal results in this test. From a genetic perspective, the assessment of sperm DNA fragmentation (SDF) is important as a parameter of sperm quality.

Methods

In this narrative study, we review and discuss pathophysiological causes, DNA repair mechanisms, and management of high SDF. We then summarize literature exploring the association between SDF and reproductive outcomes.

Main Findings

Recent systematic reviews and meta-analyses have revealed a significant association between high SDF in AMAB individuals and adverse reproductive outcomes including embryo development, natural conception, intrauterine insemination, and in vitro fertilization. However, the association with live birth rates and pregnancy rates following intracytoplasmic injection remains inconclusive. The disparities among quantitative assays, inconsistent reference range values, absent high-quality prospective clinical trials, and clinical heterogeneity in AMAB patients with elevated SDF represent the main limitations affecting SDF testing.

Conclusion

The evaluation and management of SDF plays an important role in a subset of AMAB infertility, but widespread integration into clinical guidelines will require future high-quality clinical trials and assay standardization.

Treatment progress of cryptozoospermia with Western Medicine and traditional Chinese medicine: A literature review

Background and Aims

Cryptozoospermia is an extreme oligozoospermia with an unsatisfactory treatment effect, with an incidence rate of approximately 8.73% in male infertility, whose effective solution has become the call of the times. Western Medicine has achieved certain effects through drugs, surgery, and assisted reproductive therapy, but this is still not ideal. Traditional Chinese medicine (TCM) has made many achievements in other disciplines; however, there is still a lack of evidence-based medical evidence to improve sperm production.

Methods

The relevant literatures from the China National Knowledge Internet (CNKI) and PubMed in the past 10 years were collected in this article, of which the mechanisms, advantages, or current controversies of various treatment methods of Western Medicine and TCM were analyzed, to find new treatment methods and research directions.

Results

With the development of modern science and technology, medical treatments for cryptozoospermia have become increasingly abundant; however, there is still no universally recognized unified and effective guiding plan. Although TCM has not been fully verified by evidence-based medicine, most TCM combined with Western Medicine can achieve unexpected results.

Conclusion

The combination of TCM and Western Medicine may become a bane for cryptozoospermia and bring good news to infertile men worldwide.

Sperm Chromatin Condensation Defect Accelerates the Kinetics of Early Embryonic Development but Does Not Modify ICSI Outcome

The origin and quality of gametes are likely to influence the kinetics of embryonic development. The purpose of the study was to assess the impact of sperm nuclear quality, and in particular sperm chromatin condensation, on the kinetics of early embryo development after intracytoplasmic sperm injection (ICSI). Our study included 157 couples who benefitted from ICSI for male factor infertility. Chromatin condensation and DNA fragmentation were assessed in spermatozoa prior to ICSI. Above the 20% threshold of sperm condensation defect, patients were included in the abnormal sperm chromatin condensation (ASCC) group; below the 20% threshold, patients were included in the normal sperm chromatin condensation (NSCC) group. After ICSI, the oocytes were placed in the time-lapse incubator. The kinetics of the cohort's embryonic development have been modeled. The fading times of pronuclei and the time to two blastomeres (t2, first cleavage) and four blastomeres (t4, third cleavage) differed significantly between the NSCC and ASCC groups, with earlier events occurring in the ASCC group. On the other hand, the state of sperm chromatin condensation did not seem to have an impact on live birth rates or the occurrence of miscarriages. The kinetics of early embryonic development was accelerated in males with a sperm chromatin condensation defect without compromising the chances of pregnancy or promoting miscarriage. However, our study highlights the paternal contribution to early embryonic events and potentially to the future health of the conceptus.

The effect of paternal and maternal factors on the prognosis of live birth in couples with recurrent pregnancy loss

INTRODUCTION

Currently, recurrent pregnancy loss (RPL) examinations focus on the woman, although paternal factors are also involved. Men in couples with RPL have higher sperm DNA fragmentation levels than fertile men, but the effect of sperm DNA damage on couple's later prognosis is unknown. Advanced maternal age and obesity are associated with RPL, but paternal lifestyle factors are less studied. Therefore, we aimed to study the associations of couples' lifestyle factors, causes of RPL, and sperm DNA fragmentation with their prognosis of future live birth.

MATERIAL AND METHODS

This descriptive cohort study comprised 506 couples investigated for RPL at Helsinki University Hospital, Finland, between 2007 and 2016, linked with national health and population registers. The primary outcome was couple's live birth after RPL investigations. Data on couple's background factors, including age, body mass index, smoking, and alcohol use, were collected from medical records. Sperm DNA fragmentation index was analyzed from 211 men using the sperm chromatin dispersion test. The associations between background factors, sperm DNA fragmentation, and cumulative probability of live birth over time were analyzed using cross-tabulations and age-adjusted Cox regression.

RESULTS

In all, 352 of 506 couples (69.6%) achieved live birth. Maternal age, unexplained RPL, prolonged pregnancy attempts before investigations, paternal obesity, and maternal smoking were associated with prognosis: unadjusted hazard ratio for couple's live birth for women aged 35-39 vs younger than 30 years was 0.63 (95% confidence interval [CI] 0.47-0.84), and for 40 years or older was 0.36 (95% CI 0.22-0.58). Age-adjusted hazard ratio for unexplained vs explained RPL was 1.39 (95% CI 1.12-1.72), for couple's pregnancy attempt at least 4 years vs less than 2 years was 0.50 (95% CI 0.33-0.76), for paternal body mass index at least 30 kg/m² vs less than 25 kg/m² was 0.67 (95% CI 0.46-0.98), and for maternal smoking was 0.71 (95% CI 0.51-0.99). Altogether, 96/135 (71.1%) couples with normal (<15%), 38/60 (63.3%) with intermediate (15-30%), and 11/16 (68.8%) with high sperm DNA fragmentation index achieved live birth (p = 0.56).

CONCLUSIONS

In couples with RPL, prolonged pregnancy attempts, a cause found in RPL examinations, lifestyle factors, and maternal age are negatively associated with their prognosis of future live birth. Sperm DNA fragmentation was not associated, but the number of men with damaged spermatozoa was small. We suggest that clinicians include women and men in RPL counseling because couple's joint lifestyle seems to determine their later prognosis.

Identification of differentially expressed mRNAs and miRNAs in spermatozoa of bulls of varying fertility

Bulls used in artificial insemination, with apparently normal semen quality, can vary significantly in their field fertility. This study aimed to characterize the transcriptome of spermatozoa from high (HF) and low (LF) fertility bulls at the mRNA and miRNA level in order to identify potential novel markers of fertility. Holstein-Friesian bulls were assigned to either the HF or LF group (n = 10 per group) based on an adjusted national fertility index from a minimum of 500 inseminations. Total RNA was extracted from a pool of frozen-thawed spermatozoa from three different ejaculates per bull, following which mRNA-seq and miRNA-seq were performed. Six mRNAs and 13 miRNAs were found differentially expressed (P < 0.05, FC > 1.5) between HF and LF bulls. Of particular interest, the gene pathways targeted by the 13 differentially expressed miRNAs were related to embryonic development and gene expression regulation. Previous studies reported that disruptions to protamine 1 mRNA (PRM1) had deleterious consequences for sperm chromatin structure and fertilizing ability. Notably, PRM1 exhibited a higher expression in spermatozoa from LF than HF bulls. In contrast, Western Blot analysis revealed a decrease in PRM1 protein abundance for spermatozoa from LF bulls; this was not associated with increased protamine deficiency (measured by the degree of chromatin compaction) or DNA fragmentation, as assessed by flow cytometry analyses. However, protamine deficiency was positively and moderately correlated with the percentage of spermatozoa with DNA fragmentation, irrespective of fertility group. This study has identified potential biomarkers that could be used for improving semen quality assessments of bull fertility.

Subclinical Hypothyroidism and Sperm DNA Fragmentation: A Cross-sectional Study of 5401 Men Seeking Infertility Care

CONTEXT

Our previous study showed that paternal subclinical hypothyroidism (SCH) had a detrimental effect on the clinical outcomes of assisted reproductive technologies. However, it remains to be determined whether paternal SCH affects sperm DNA integrity.

OBJECTIVE

To investigate the association between SCH and sperm DNA fragmentation in men seeking infertility care.

METHODS

This cross-sectional study included 4983 men with euthyroidism and 418 men with SCH seeking infertility treatment in a tertiary care academic medical center between January 2017 and December 2021. The outcome measures were the absolute DNA fragmentation index (DFI) and the risk of abnormal DFI (defined as DFI ≥ 25% or ≥ 30%).

RESULTS

The mean (SD) age of men with euthyroidism and men with SCH was 34.20 (5.97) and 35.35 (6.48) years, respectively (P < 0.001). The difference in DFI was not statistically significant (adjusted mean: 19.7% vs 18.9% in the SCH and euthyroidism groups, respectively; P = 0.07) after confounder adjustment. A DFI ≥25% was significantly more frequent in men with SCH (20.57%) than in men with euthyroidism (14.49%) after confounder adjustment [odds ratio (OR) 1.43 (95% CI 1.09-1.88)]. DFI ≥ 30% was also significantly more common in men with SCH (11.72%) than in men with euthyroidism [6.74%; OR 1.84 (95% CI 1.34-2.52)]. In addition, thyroid-stimulating hormone concentration was significantly associated with an increased risk of having a DFI ≥25% (P < 0.001) or ≥30% (P = 0.011).

CONCLUSION

SCH was significantly associated with an increased risk of an abnormal DFI.

Do follicle-stimulating hormone receptor polymorphisms in infertile men influence intracytoplasmic sperm injection outcomes? A prospective cohort study

The follicle-stimulating hormone (FSH) and its receptor regulate the quantity and quality of spermatozoa production. Several studies have analyzed the effect of single nucleotide polymorphisms (SNPs) in exon 10 of the FSH receptor (FSHR) on basic semen parameters without yet reaching a firm consensus. The aim of this study was to evaluate the effect of p.Thr307Ala and p.Asn680Ser polymorphisms in exon 10 of the FSHR gene, in infertile men, on intracytoplasmic sperm injection (ICSI) outcomes. This study was conducted between March 2019 and February 2020 on infertile couples undergoing ICSI at Al Hadi Laboratory and Medical Center, Lebanon. Couples with severe infertility factors that may impair gametogenesis/embryogenesis (e.g. advanced maternal age, premature ovarian failure, underwent gonadotoxic treatments, etc.) were excluded from the study. Semen and blood samples were collected from infertile men on the day of oocyte collection. Infertile men (n = 173) were screened for FSHR variants using polymerase chain reaction-restriction fragment length polymorphism. Moreover, fertilization rates, embryo quality, and pregnancy outcomes were evaluated. Higher sperm concentrations were found in the p.Thr307Ala group than the p.Thr307Thr (P < 0.01) and p.Ala307Ala (P < 0.05) groups. Furthermore, fertilization rate was significantly lower in the p.Ala307Ala genotype than in the p.Thr307Thr genotype (P < 0.05). We showed that FSHR variants in infertile men undergoing ICSI could affect sperm concentration, motility, and fertilization rates. Therefore, it will be important to confirm these results in further studies using a larger sample size.

Increased sperm DNA damage leads to poor embryo quality and subfertility of male rats treated with methylphenidate hydrochloride in adolescence

BACKGROUND

Methylphenidate hydrochloride (MPH) is a psychostimulant widely used in the treatment of attention deficit hyperactive disorder (ADHD), as well as a performance enhancer, for at least 60 years. Despite the notable effectiveness as a psychostimulant, ADHD is a chronic disorder and has a two-third chance of accompanying the individual throughout life. Long-term use of MPH has been associated not only with an increase in the development of neurodegenerative diseases, but it also has side effects on male fertility in experimental animals.

OBJECTIVES

To investigate whether methylphenidate poses a risk to sperm DNA structure and to the quality of embryos conceived after treatment during adolescence in rats.

MATERIALS AND METHODS

Wistar rats at 38 days of age were treated either with 5 mg/kg body weight of MPH, in a single daily dose for 30 days, via gavage or with distilled water-only protocol. Levels of oxidative stress in testicular and epididymal tissues were evaluated. Sperm chromatin quality and acrosome integrity was assessed under flow cytometry. From 107 days of age, animals were mated with untreated females. The effects of the paternal contribution at two different embryo development moments - cleavage stage (2.5 days post coitum) and late gestation (20 days post coitum) - were analyzed.

RESULTS

MPH caused high levels of sperm DNA damage, which was reflected in 40% of decrease in early embryo quality and a lower number of live pups at 20 dpc.

DISCUSSION

The high level of fragmentation seen in the embryos sired from the MPH group is consistent with the poor chromatin structure of the sperm, and does not seem to be a result of oxidative stress in the reproductive tissues.

CONCLUSIONS

The results presented here suggest that the subchronic use of MPH during male prepubertal phase may cause long term subfertility and compromise embryo survival. This article is protected by copyright. All rights reserved.

Juvenile exposure and adult risk assessment with single versus repeated exposure of melphalan in the germ cells of male SD rat: Deciphering the molecular mechanisms

Melphalan significantly contributes to the increase in childhood cancer survival rate. It acts as a gonadotoxic agent and leads to testes damage, dysbalance in gonadal hormones, and impairment in the germ cell proliferation. Therefore, it might be a potent threat to male fertility in individuals who have undergone melphalan treatment during childhood cancer. However, the molecular mechanisms of melphalan-induced gonadal damage are not yet fully explored and they need to be investigated to determine the benefit-risk profile. In the present study, juvenile male SD rats were subjected to single and intermittent cycles of melphalan exposure in a dose-dependent (0.375, 0.75 and 1.5 mg/kg) manner. Methods of end-points evaluations were quantification of micronuclei formation in peripheral blood, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, histological studies in testes, oxidative/nitrosative stress parameters. A single cycle of exposure at high dose (1.5 mg/kg) produced significant effect on micronuclei formation only after the first week of exposure, whereas failed to produce significant effect at the end of the sixth week. Intermittent cycles of exposure at the dose of 1.5 mg/kg produced significant alterations in all the parameters (micronuclei in peripheral blood, testes and epididymides weight and length, MDA, GSH and nitrite levels, sperm count and motility, sperm head morphology, testicular and sperm DNA damage, protein expression in testes and histological parameters). So, time of exposure as well as the amount of exposure (total dosage administered) is critical in determining the magnitude of the damage in germ cell risk assessment.

Comparison of sperm preparation methods to improve the recovery of mature spermatozoa in sub-fertile males

The integrity of chromatin in the spermatozoon is essential for reproductive outcome. The aim of this study was to evaluate the most effective and cost-effective method to reduce the percentage of spermatozoa with defects in chromatin decondensation for use in assisted reproductive technologies (ART) procedures. Sperm samples from 15 sub-fertile males were examined at CFA Naples to determine the sperm decondensation index (SDI), using the aniline blue test, before and after preparation, comparing density gradients with two different swim-up approaches. All three techniques led to a reduction in decondensed spermatozoa with no statistical difference (P > 0.05) between the control and the treated sperm. In contrast, we found a highly significant decrease in SDI (P < 0.01) after the two swim-up methods in all the samples, confirming the efficacy of these methods in lowering the percentage of chromatin compaction damage. There was no statistical difference between the two swim-up methods, however swim-up from the pellet led to improved count, motility and the percentage of normal condensed spermatozoa. We suggest that swim-up from the pellet be used in ART on sub-fertile males, both to reduce cell stress by multiple centrifugation and improve the recovery rate of mature spermatozoa.

Can sperm quality influence embryo development and its ploidy? Analysis of 811 blastocysts obtained from different sperm sources

The aim of our study was to evaluate the correlation between sperm quality and ploidy status of the derived blastocysts. We performed a retrospective analysis on a restricted pool of patients enrolling only those who had no female factors. Male patients with genetic factors affecting spermatogenesis were also excluded. We chose a maternal age ≤38 years to decrease the female factor, therefore the male factor was the main component of sterility. We divided the patients in four groups based on semen quality and comparing fertilization, pregnancy and euploidy rates above all. In total, 201 intracytoplasmic sperm injection (ICSI) cycles were enrolled in the study. Cycles were divided into four groups, according to semen source: normal semen, oligoasthenoteratozoospermia (OAT), cryptospermia or non-obstructive azoospermia (NOA). An extremely statistically lower fertilization rate was found in NOA patients. Unexpectedly, no differences were detected in blastocyst formation, euploidy, aneuploidy and mosaicism rates among the four groups. Interestingly, we also found a higher abortion rate comparing NOA to normal semen with an odds ratio of 4.67. In our study no statistically significant differences among the analyzed groups were found, showing little or no effect at all using spermatozoa from different semen sources or quality. This may be linked to the oocyte competence of fixing sperm DNA damage and it could be hypothesized that only sperm with a good rate of DNA integrity are able to fertilize the oocyte, explaining why poor quality semen is reflected in a low fertilization rate without effect on ploidy.

Carryover effects of feeding bulls with an omega-3-enriched-diet-From spermatozoa to developed embryos

The impact of omega-3 nutritional manipulation on semen cryosurvival and quality post thawing is controversial. Our aim was to examine how feeding bulls with omega-3 supplementation from different sources affects the spermatozoa quality parameters. Fifteen Israeli Holstein bulls were fed for 13 weeks with a standard ration top-dressed with encapsulated-fat supplementation: fish or flaxseed oil or saturated fatty acids (control). Ejaculates were collected before, during, and after the feeding trial. Frozen–thawed samples were evaluated by a flow cytometer for spermatozoa viability, mitochondrial membrane potential, the level of reactive oxygen species (ROS), acrosome membrane integrity, DNA fragmentation, phosphatidylserine translocation, and membrane fluidity. Both fish and flaxseed oil treatment resulted in lower ROS levels vs. control groups, during and after the feeding trial. Fewer spermatozoa with damaged acrosomes were observed in the fish oil group after the feeding trial. The spermatozoa membrane fluidity was altered in both the fish and flaxseed oil groups throughout the feeding trial, but only in the flaxseed oil group after the feeding trial. The proportion of spermatozoa with fragmented DNA was lower in the flaxseed oil group after the feeding trial. The spermatozoa fertilization competence did not differ between groups however, blastocyst formation rate was higher in the fish and flaxseed oil groups relative to the control. This was associated with differential gene expression in the blastocysts. Overall, the omega-3-enriched food improved the spermatozoa characteristics; this was further expressed in the developing blastocysts, suggesting a carryover effect from the spermatozoa to the embryos.

The Capacity to Repair Sperm DNA Damage in Zygotes is Enhanced by Inhibiting WIP1 Activity

Maintaining genome integrity in germ cells is essential not only for successful fertilization and embryo development, but also to ensure proper transmission of genetic information across generations. However, unlike oocytes, sperm are incapable of repairing DNA damage. Therefore, sperm DNA damage is repaired after fertilization in zygotes using maternal DNA repair factors. In this study, we found that zygotic repair of paternal DNA damage is enhanced by inhibiting WIP1 activity. Oxidative stress induced DNA damage in sperm and severely impaired motility. Although DNA damage in sperm did not compromise fertilization, it increased DNA damage in the paternal pronucleus of zygotes. However, WIP1 inhibition during fertilization reduced DNA damage in the paternal pronucleus, improving the rate of two-cell development, and subsequent zygotic genome activation. Therefore, our results suggest that WIP1 inhibition could enhance maternal DNA repair capacity and thereby decrease paternal DNA damage in zygotes.

Resveratrol benefits on sperm DNA, chromatin structure and reproductive outcomes of varicocelized rats

In varicocele, the main cause of sperm DNA damage is oxidative stress (OS). Resveratrol, a polyphenol with antioxidant properties, can protect cells from injuries caused by OS. We investigated the benefits of resveratrol against reproductive damage caused by experimental varicocele induced from peripuberty. Eighty peripubertal male rats were distributed into 4 groups: sham-control (S), varicocele (V), resveratrol (R) and varicocele treated with resveratrol (VR). Varicocele was induced through the partial ligature of the left renal vein. Resveratrol was given in a daily dose of 300 mg/kg body weight (gavage). Sperm samples were collected at 100 days of age for vitality, DNA fragmentation and chromatin protamination evaluations. OS analyses were carried out. Rats from all groups were mated with healthy primiparous females for evaluation of reproductive capacity and embryonic quality. The V group showed reduction of sperm vitality, altered chromatin protamination and sperm DNA integrity and high levels of OS. The VR group showed an improvement of oxidative status, sperm vitality, DNA integrity and chromatin structure, and an enhancement in the gestational index and embryonic quality. Therefore, we showed in this experimental model that resveratrol is a promising nutraceutical adjuvant and should be deeply studied to mitigate subfertility in varicocele.

GnRH-agonist pretreatment in hormone replacement therapy improves pregnancy outcomes in women with male-factor infertility

OBJECTIVE

This study aimed to examine the efficacy of HRT with gonadotropin-releasing hormone agonist (GnRH-a) pre-treatment in women with male-factor infertility who underwent a frozen embryo transfer (FET) programme.

DESIGN

Between January 2016 and October 2020, 2733 women with male-factor infertility who underwent the HRT protocol as the endometrial preparation method were enrolled at two Reproductive Medicine Centres. Patients were divided into two groups based on whether they had GnRH-a pre-treatment before HRTs: the GnRHa-HRT group and the HRT group. The inverse probability of treatment weighting (IPTW) method was conducted to balance patient baseline characteristics between treatment cohorts to reduce selection bias. The live birth rate was considered regarded as the primary pregnancy outcome.

RESULTS

Multivariate logistic regression adjusted for confounding factors, the GnRHa-HRT group showed a notably higher rate of live birth (OR 2.154, 95% CI 1.636~2.835, P<0.001) when compared to the HRT group. Additionally, the rate of miscarriage was significantly lower in the GnRHa-HRT group. The GnRHa-HRT group had significantly higher rates of biochemical pregnancy, clinical pregnancy, multiple pregnancy, and term birth.

CONCLUSION

The endometrial preparation protocol of HRT with GnRH-a pre-treatment could obviously increase the live birth rate for women with male-factor infertility undergoing the FET programme.

Effects of paternal overnutrition and interventions on future generations

In the last two decades, evidence from human and animal studies suggests that paternal obesity around the time of conception can have adverse effects on offspring health through developmental programming. This may make significant contributions to the current epidemic of obesity and related metabolic and reproductive complications like diabetes, cardiovascular disease, and subfertility/infertility. To date, changes in seminal fluid composition, sperm DNA methylation, histone composition, small non-coding RNAs, and sperm DNA damage have been proposed as potential underpinning mechanism to program offspring health. In this review, we discuss current human and rodent evidence on the impact of paternal obesity/overnutrition on offspring health, followed by the proposed mechanisms, with a focus on sperm DNA damage underpinning paternal programming. We also summarize the different intervention strategies implemented to minimize effects of paternal obesity. Upon critical review of literature, we find that obesity-induced altered sperm quality in father is linked with compromised offspring health. Paternal exercise intervention before conception has been shown to improve metabolic health. Further work to explore the mechanisms underlying benefits of paternal exercise on offspring are warranted. Conversion to healthy diets and micronutrient supplementation during pre-conception have shown some positive impacts towards minimizing the impact of paternal obesity on offspring. Pharmacological approaches e.g., metformin are also being applied. Thus, interventions in the obese father may ameliorate the potential detrimental impacts of paternal obesity on offspring.

The Effect of Sperm DNA Fragmentation on In Vitro Fertilization Outcomes for Women With Polycystic Ovary Syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disease in reproductive women associated with poor pregnancy outcomes. In modern society, people pay more attention to the female factor, but it is uncertain whether sperm quality is another factor affecting pregnancy outcomes of patients with PCOS.

METHOD

The effect of sperm DNA fragmentation (SDF) on oocyte fertilization, embryonic development, and pregnancy outcomes for patients with PCOS who underwent in vitro fertilization (IVF) treatment was studied. A total of 141 PCOS patients and 332 control patients undergoing IVF treatment were recruited from January 2017 to December 2019. All female patients were designated into two groups according to the Rotterdam criteria. Each group was divided into two sets, DNA fragmentation index (DFI) ≤15% and DFI > 15%, on the basis of sperm DFI.

RESULT

There were no differences in basic clinical characteristics between couples with a sperm DFI ≤ 15% or DFI > 15%. For control patients, no differences were observed in IVF outcomes. However, for PCOS patients, although there were no differences in the fertilization (60.4% vs. 59.9%, p = 0.831), high-quality embryo (68.5% vs. 67.9% p = 0.832), clinical pregnancy (78.4% vs. 66.7%, p = 0.148), and abortion (12.5% vs. 11.5%, p = 1.000) rates, a significantly lower high-quality blastocyst formation rate (26.3% vs. 16.3%, p = 0.023) was observed for couples with a sperm DFI > 15% compared with a sperm DFI ≤ 15%.

CONCLUSION

For PCOS patients undergoing IVF, oocytes fertilized using sperm with higher DFI led to a lower high-quality blastocyst formation rate but had no influence on fertilization, high-quality embryo, clinical pregnancy, and miscarriage rates.

Analysis and quantification of female and male contributions to the first stages of embryonic kinetics: study from a time-lapse system

PURPOSE

The few studies that examined the effect of male and/or female features on early embryo development, notably using the time-lapse system (TL), reported conflicting results. This can be explained by the small number of studies using an adapted model.

METHODS

We used two original designs to study the female and male effects on embryo development: (1) based on embryos from donor oocytes (TL-DO), and (2) from donor sperm (TL-DS). Firstly, we analyzed the female and male similarities using an ad hoc intraclass correlation coefficient (ICC), then we completed the analysis with a multivariable model to assess the association between both male and female factors, and early embryo kinetics. A total of 572 mature oocytes (TL-DO: 293; TL-DS: 279), fertilized by intracytoplasmic sperm injection (ICSI) and incubated in a TL (Embryoscope®) were included from March 2013 to April 2019; 429 fertilized oocytes (TL-DO: 212; TL-DS: 217) were assessed. The timings of the first 48 h have been analyzed.

RESULTS

The similarities in the timings thought to be related to the female component were significant: (ICC in both DO-DS designs respectively: tPB2: 9-18%; tPNa: 16-21%; tPNf: 40-26%; t2: 38-24%; t3: 15-20%; t4: 21-32%). Comparatively, those related to male were lower. Surprisingly after multivariable analyses, no intrinsic female factors were clearly identified. However, in TL-DO design, oligozoospermia was associated with a tendency to longer timings, notably for tPB2 (p = 0.026).

CONCLUSION

This study quantifies the role of the oocyte in the first embryo cleavages, but without identified specific female factors. However, it also highlights that sperm may have an early embryonic effect.

Sperm DNA fragmentation in reproductive medicine: A review

Approximately 15% of the world's couples suffer from infertility during their reproductive period of which the male factor is responsible for 50% of cases. Male factor infertility is multifactorial in origin, and sperm DNA fragmentation (SDF) has also been linked to male infertility including idiopathic male infertility. Some degree of controlled DNA nicking is essential for adequate DNA compaction, but excessive SDF is usually associated with reduced male fertility potential, reduced fertilisation, poor embryo quality, recurrent pregnancy loss and poor assisted reproductive techniques (ARTs) outcomes. Although semen analysis remains the gold standard for diagnosis of male factor infertility worldwide, its limitations motivated the search and the development of complementary tests of sperm function and integrity. SDF assay is an emerging diagnostic tool in infertile men, and several indications for SDF testing in infertile couples have also been proposed. The use of SDF in routine male infertility assessment is, however, still controversial. Furthermore, both direct and indirect SDF tests are now available. Hence, the present review was conducted to summarise the recent evidence of SDF, underlying mechanisms, clinical indications, diagnostic tests, as well as the role of SDF in male factor infertility, pregnancy and ART outcomes.

Paternal inflammatory arthritis is associated with a higher risk of miscarriage: results of a large multicenter study (iFAME-Fertility)

Objectives

Paternal preconception health is recognized as an important contributor to pregnancy outcomes. Nonetheless, pregnancy outcomes of partners of men with inflammatory arthritis (IA) have never been studied. Our objective was to describe the pregnancy outcomes of partners of men diagnosed with IA.

Methods

We performed a multicentre cross-sectional retrospective study conducted in the Netherlands. Men with IA who were over 40 years old that reported at least one positive pregnancy test were included. To analyse the impact of IA on pregnancy outcomes, pregnancies were classified into two groups: pregnancies conceived after the diagnosis of IA and before the diagnosis of IA.

Results

In total, 408 male participants diagnosed with IA reported 897 singleton pregnancies that resulted in 794 live births. Pregnancies conceived after the diagnosis of IA had higher rate of miscarriage (12.27 vs 7.53%, P = <0.05). This increased risk was still present after adjusting for confounders [OR 2.03 (95% CI 1.12, 3.69) P = 0.015].

Conclusions

This is the largest study to describe the pregnancy outcomes of partners of men diagnosed with IA and the first to demonstrate that paternal IA is associated with a higher risk of miscarriage. Notwithstanding, the overall rate of miscarriage reported in our study could be comparable to previously reported population estimates.

Beckwith-Wiedemann syndrome: Clinical, histopathological and molecular study of two Tunisian patients and review of literature

Background

Beckwith–Wiedemann syndrome (BWS) is a rare overgrowth syndrome characterized by congenital malformations and predisposition to embryonic tumors. Loss of methylation of imprinting center 2 (IC2) is the most frequent alteration and rarely associated with tumors compared to paternal uniparental disomy of chromosome 11 (UPD(11)pat) and gain of methylation of imprinting center 1.

Methods

Our study aimed to describe the clinical, histopathological and genetic characteristics of two patients and establish genotype‐phenotype correlations. The clinical diagnosis was based on the criteria defined by the international expert consensus of BWS. Molecular study of 11p15.5 methylation status was assessed using methylation‐specific‐multiplex ligation probe amplification (MS‐MLPA).

Results

Patients were aged 12 months and 3 months and fulfilled the clinical score of BWS. MS‐MLPA showed molecular alterations consisting of loss of methylation in IC2 (IC2‐LOM) at the maternal allele for one patient and a mosaic UPD(11)pat for the second patient in whom follow‐up at 6months revealed adrenocortical carcinoma (ACC) with low grade of malignancy. Molecular subtypes guide the follow‐up and tumor surveillance, our major concern.

Conclusion

We have to take into account the psychological impact of a possible tumor whatever the underlying mechanism is. Nevertheless, the tumor risk remains high for UPD(11)pat. Our study extended the phenotype of BWS with absence of macrosomia in Tunisian patients, contrasting with literature, and added a supplementary case of ACC in the tumor spectrum of BWS patients with UPD(11)pat.

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.

Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos’ arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.

Oral Antioxidant Treatment of Men Significantly Improves the Reproductive Outcome of IVF Cycles

Some 30% to 80% of male sub-fertility may be associated with oxidative stress that damages spermatozoa and can decrease success of in vitro fertilization (IVF) techniques. This multicenter, longitudinal, prospective study aimed to investigate whether oral antioxidant supplementation improved the reproductive competence of men who had had low fertilization rates in their previous intracytoplasmic sperm injection (ICSI) cycles without azoospermia or severe oligozoospermia or any identifiable andrological disease. Seventy-seven men from couples who had an ICSI attempt with unexplained <60% fertilization rate took an antioxidant mix of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, and vitamins B2, B6, and B12. Semen parameters were analyzed before (T0) and after 90 days (T90) of treatment, and outcomes of the paired T0 and T90 cycles were compared. After the treatment there was an increase in sperm concentration (p = 0.027), total motile sperm count (p = 0.003), progressive motility (p < 0.0001), and a decreasing trend of DNA-fragmented spermatozoa. Embryological outcomes (fertilization, embryo quality, blastocyst development) were significantly higher in T90 than T0 cycles. No T0 cycle resulted in an evolutive pregnancy. Conversely, in T90 cycles 29 singleton clinical pregnancies were obtained. No negative neonatal outcomes were recorded in newborns after antioxidant treatment. Diet supplementation of men who have had low fertilization rates in their previous ICSI cycles with a combination of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, betaine, and vitamins may improve semen reproductive potential and ICSI clinical outcome.

Oral Antioxidant Treatment of Men Significantly Improves the Reproductive Outcome of IVF Cycles

Some 30% to 80% of male sub-fertility may be associated with oxidative stress that damages spermatozoa and can decrease success of in vitro fertilization (IVF) techniques. This multicenter, longitudinal, prospective study aimed to investigate whether oral antioxidant supplementation improved the reproductive competence of men who had had low fertilization rates in their previous intracytoplasmic sperm injection (ICSI) cycles without azoospermia or severe oligozoospermia or any identifiable andrological disease. Seventy-seven men from couples who had an ICSI attempt with unexplained <60% fertilization rate took an antioxidant mix of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, and vitamins B2, B6, and B12. Semen parameters were analyzed before (T0) and after 90 days (T90) of treatment, and outcomes of the paired T0 and T90 cycles were compared. After the treatment there was an increase in sperm concentration (p = 0.027), total motile sperm count (p = 0.003), progressive motility (p < 0.0001), and a decreasing trend of DNA-fragmented spermatozoa. Embryological outcomes (fertilization, embryo quality, blastocyst development) were significantly higher in T90 than T0 cycles. No T0 cycle resulted in an evolutive pregnancy. Conversely, in T90 cycles 29 singleton clinical pregnancies were obtained. No negative neonatal outcomes were recorded in newborns after antioxidant treatment. Diet supplementation of men who have had low fertilization rates in their previous ICSI cycles with a combination of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, betaine, and vitamins may improve semen reproductive potential and ICSI clinical outcome.

Correlation between sperm DNA fragmentation index and semen parameters in 418 men seen at a fertility center

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Comprehensive functional analysis reveals that acrosome integrity and viability are key variables distinguishing artificial insemination bulls of varying fertility

In vitro methods of assessing bull semen quality in artificial insemination (AI) centers are unable to consistently detect individuals of lower fertility, and attempts to reliably predict bull fertility are still ongoing. This highlights the need to identify robust biomarkers that can be readily measured in a practical setting and used to improve current predictions of bull fertility. In this study, we comprehensively analyzed a range of functional, morphological, and intracellular attributes in cryopreserved spermatozoa from a selected cohort of Holstein Friesian AI bulls classified as having either high or low fertility (n = 10 of each fertility phenotype; difference of 11.4% in adjusted pregnancy rate between groups). Here, spermatozoa were assessed for motility and kinematic parameters, morphology, acrosome integrity, plasma membrane lipid packing, viability (or membrane integrity), superoxide production, and DNA integrity. In addition, spermatozoa were used for in vitro fertilization to evaluate their capacity for fertilization and successful embryo development. The information collected from these assessments was then used to phenotypically profile the 2 groups of bulls of divergent fertility status as well as to develop a model to predict bull fertility. According to the results, acrosome integrity and viability were the only sperm attributes that were significantly different between high- and low-fertility bulls. Interestingly, although spermatozoa from low-fertility bulls, on average, had reduced viability and acrosome integrity, this response varied considerably from bull to bull. Principal component analysis revealed a sperm phenotypic profile that represented a high proportion of ejaculates from low-fertility bulls. This was constructed based on the collective influence of several sperm attributes, including the presence of cytoplasmic droplets and superoxide production. Finally, using the combined results as a basis for modeling, we developed a linear model that was able to explain 47% of the variation in bull field fertility in addition to a logistic predictive model that had a 90% chance of distinguishing between fertility groups. Taken together, we conclude that viability and acrosome integrity could serve as fertility biomarkers in the field and, when used alongside other sperm attributes, may be useful in detecting low-fertility bulls. However, the variable nature of low-fertility bulls suggests that additional, in-depth characterization of spermatozoa at a molecular level is required to further understand the etiology of low fertility in dairy bulls.

The paternal toolbox for embryo development and health

The sperm is essential for reconstitution of embryonic diploidy and highly specialized developmental functions. Immediately after gamete fusion, the sperm-borne PLC-zeta triggers activation, generating intracellular free Ca2+ oscillations. Mutations in the PLC-zeta encoding gene are associated with the absence of this factor in mature sperm and inability to achieve fertilization. Sperm play also a role in the greater game of the choreography of fertilization. In the human, the sperm centrioles are introduced into the oocyte environment with gamete fusion. They interact with the oocyte cytoskeletal apparatus to form a functional pair of centrosomes and ultimately regulate pronuclear juxtaposition in preparation for the first cleavage. As a consequence, the fidelity of chromosome segregation during the first cell divisions depends on the function of sperm centrioles. Sperm DNA integrity is essential for embryo development and health. Damaged DNA does not impact on the sperm fertilization ability following ICSI. However, detrimental effects emerge at pre- and post-implantation stages. Sperm-specific epigenetic factors also play an active role in the regulation of embryonic development, as shown by correlations between reduced embryo morphological quality and incorrect chromatin packaging during spermiogenesis or abnormal methylation of sperm CpG islands. This functional landscape demonstrates that the contribution of the sperm to development goes far beyond its well-established role in fertilization. Clinical studies confirm this view and indicate sperm function as a crucial aspect of research to increase the efficacy of assisted reproduction treatments.

Desmosterol Incorporation Into Ram Sperm Membrane Before Cryopreservation Improves in vitro and in vivo Fertility

Pregnancy rates in ewes are markedly low after cervical insemination with frozen-thawed sperm. Sensitivity of ram sperm to freeze-thawing is related to the lipid composition of the membrane, particularly to its low sterol content. Recently, we proved that sterol content of ram sperm can be increased by treatment with methyl-β-cyclodextrin-sterol complexes and we provided mechanistic based evidence on the differential behavior of cholesterol and desmosterol in the ram sperm membrane. In the present study, we evaluated the role of increasing cholesterol and desmosterol content of ram sperm before cryopreservation, on the extent and distribution of sterols, cryocapacitation status, acrosome integrity, DNA damage associated with apoptosis and fertility competence in vitro and in vivo of post-thawed sperm. After freeze-thawing, similar levels of sterol content were evidenced in control sperm cells and in those pre-incubated with either cholesterol or desmosterol. Still, moderately higher levels of sterols were registered in treated sperm compared to the control, indicating no physiological excess of sterols after thawing or sterol losses that exceed the control. Live cell imaging of fluorescent cholesterol evidenced the presence of sperm sub-populations differentially affected by freeze-thawing. Similar unimodal frequency profiles were observed between sterol-enriched groups, while the control exhibited a sub-population of sperm compatible with low sterol content. Tyrosine phosphorylation was significantly lower when ram sperm incorporated cholesterol compared to the control. No difference in this capacitation parameter was found between the latter and desmosterol-enriched sperm. The percentage of sperm with damaged acrosomes post-thawing, assessed by a fluorescent lectin, was reduced in sperm that incorporated sterols before freezing, irrespective of the sterol class. These results suggest that sterols exert a stabilizing effect on the acrosome. No differences were found in levels of apoptotic DNA fragmentation among experimental groups. As to fertility trials, desmosterol-enriched sperm gave rise to higher rates of in vitro activated oocytes by heterologous fertilization and to significantly lower pregnancy loss in vivo. Our research provides new insights on sterol incorporation into ram sperm prior to cryopreservation, in particular on the additional benefit of incorporating desmosterol as a strategy to improve fertility outcome.

Use of testicular sperm in couples with SCSA-defined high sperm DNA fragmentation and failed intracytoplasmic sperm injection using ejaculated sperm

Sperm DNA fragmentation (SDF) has been linked with male infertility, and previous studies suggest that SDF can have negative influence on pregnancy outcomes with assisted reproduction. We performed a retrospective review of consecutive couples with a high SDF level that had intracytoplasmic sperm injection (ICSI) using testicular sperm (T-ICSI). We compared the T-ICSI outcomes to that of two control groups: 87 couples with failed first ICSI cycle and who had a second ICSI cycle using ejaculated sperm (Ej-ICSI), and 48 consecutive couples with high sperm chromatin structure assay (SCSA)-defined SDF (>15%) that underwent an ICSI cycle using ejaculated sperm after one or more failed ICSI cycles (Ej-ICSI-high SDF). The mean number of oocytes that were retrieved and the total number of embryos were not different among the three groups. The mean number of transferred embryos in the T-ICSI group was higher than the Ej-ICSI group but not significantly different than the Ej-ICSI-high SDF group (1.4, 1.2, and 1.3, respectively, P < 0.05). Clinical pregnancy rate in the T-ICSI group was not significantly different than the Ej-ICSI and Ej-ICSI-high SDF groups (48.6%, 48.2%, and 38.7%, respectively, P > 0.05). No significant difference was found in live birth rate when comparing T-ICSI to Ej-ICSI and Ej-ICSI-high SDF groups. The results suggest that pregnancy outcomes and live birth rates with T-ICSI are not significantly superior to Ej-ICSI in patients with an elevated SCSA-defined sperm DNA fragmentation and prior ICSI failure(s).