Paternal influence of sperm DNA integrity on early embryonic development

Role of Oxidative Stress in Male Infertility: An Updated Review

Current evidence links oxidative stress (OS) to male infertility, reduced sperm motility, sperm DNA damage and increased risk of recurrent abortions and genetic diseases. A review of PubMed, Medline, Google Scholar, and Cochrane review databases of published articles from years 2000–2018 was performed focusing on physiological and pathological consequences of reactive oxygen species (ROS), sperm DNA damage, OS tests, and the association between OS and male infertility, pregnancy and assisted reproductive techniques outcomes. Generation of ROS is essential for reproductive function, but OS is detrimental to fertility, pregnancy, and genetic status of the newborns. Further, there is a lack of consensus on selecting OS test, type, and duration of antioxidants treatment as well as on the target patients group. Developing advanced diagnostic and therapeutic options for OS is essential to improve fertility potential and limit genetic diseases transmitted to offspring.

Effect of Spermatic Nuclear Quality on Live Birth Rates in Intracytoplasmic Sperm Injection

Background:

Our study defines the clinical role of sperm DNA damage in the assisted reproductive technology procedure.

Aim:

To investigate if the compaction of chromatin explored added to the analysis of the sperm DNA fragmentation allows obtaining a new indicator for sperm genome quality linked to live birth rate (LBR).

Design:

This was a prospective study, undergoing 101 cycles in the intracytoplasmic sperm injection (ICSI) program.

Materials and Methods:

The sperm DNA fragmentation index (DFI) has been measured with sperm chromatin dispersion examination. The sperm decondensation index (SDI) of chromatin has been measured with aniline blue procedure; with these indexes, a new parameter has been created: DFI × SDI.

Statistical Analysis:

Pearson's correlation coefficient, Student's t-test, and Chi-square test were used. The quantitative variables were described as mean ± standard deviation. Multivariate logistic regressions were performed with live birth as outcome.

Results:

The sperm concentration, motility, and normal morphology were lower when the DFI was high (P = 0.001). The fertilization rates and the number of obtained embryos were not statistically significant different according to the DFI groups. The SDI does not appear to be linked either with the spermatic parameters or with the ICSI parameters. A low DFI seems to be a beneficial factor to obtain a live birth in ICSI procedure (P = 0.064). In case of high DFI, a high SDI allows to obtain a higher LBR than a low SDI.

Conclusion:

The DFI is a good prognostic for a delivery rate in ICSI procedure, and the SDI could be added to DFI to create a new parameter of sperm nuclear quality. This new parameter seems to be linked to LBR.

Paternal factors contributing to embryo quality

PURPOSE

Advancing maternal and paternal age leads to a decrease in fertility, and hence, many infertile couples opt for assisted reproductive technologies [ART] to achieve biological parenthood. One of the key determinants of achieving a live outcome of ART, embryo quality, depends on both the quality of the oocyte and sperm that have created the embryo. Several studies have explored the effect of oocyte parameters on embryo quality, but the effects of sperm quality on the embryo have not been comprehensively evaluated.

METHOD

In this review, we assess the effect of various genetic factors of paternal origin on the quality and development of the embryo.

RESULTS

The effects of sperm aneuploidy, sperm chromatin structure, deoxyribonucleic acid [DNA] fragmentation, role of protamines and histones, sperm epigenetic profile, and Y chromosome microdeletions were explored and found to negatively affect embryo quality.

CONCLUSION

We propose that careful assessment of spermatozoal parameters is essential to achieve embryo development and a healthy live birth. However, the heterogeneity in test results and the different approaches of assessing a single sperm parameter highlight the need for more research and the development of standardized protocols to assess the role of sperm factors affecting embryo quality.

Functional Analysis of Human Pathological Semen Samples in an Oocyte Cytoplasmic Ex Vivo System

Human fertilization and embryo development involve a wide range of critical processes that determine the successful development of a new organism. Although Assisted Reproduction Technologies (ART) may help solve infertility problems associated to severe male factor, the live birth rate is still low. A high proportion of ART failures occurs before implantation. Understanding the causes for these failures has been difficult due to technical and ethical limitations. Diagnostic procedures on human spermatozoa in particular have been limited to morphology and swimming behaviours while other functional requirements during early development have not been addressed due to the lack of suitable assays. Here, we have established a quantitative system based on the use of Xenopus egg extracts and human spermatozoa. This system provides novel possibilities for the functional characterization of human spermatozoa. Using clinical data we show that indeed this approach offers a set of complementary data for the functional evaluation of spermatozoa from patients.

What should be done for men with sperm DNA fragmentation?

In an age when a small quantity of sperm can lead to pregnancy through in vitro fertilization or intracytoplasmic sperm injection, selecting healthy sperm is important. Sperm DNA fragmentation (SDF) is known to be higher in infertile men. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and the alkaline comet test are SDF tests that directly measure DNA damage and have shown closer correlations with assisted reproduction results than indirect tools such as the sperm chromatin structure assay or the sperm chromatic dispersion test. It is difficult; however, to endorse a single test as the best test overall; instead, it is best to select a testing method based on each patient's clinical condition and goals. In a couple struggling with infertility, if the male partner has a high level of SDF, he should aim to decrease SDF through lifestyle modifications, antioxidant treatment, and ensuring an appropriate duration of abstinence, and physicians need to treat the underlying diseases of such patients. If sperm DNA damage continues despite the patient's and physician's efforts, other methods, such as micromanipulation-based sperm selection or testicular sperm extraction, should be used to select healthy sperm with nuclear DNA integrity.

Congenital anomalies in infants conceived by infertile women through assisted reproductive technology: A cohort study 2004-2014

This retrospective cohort study aimed to analyse the risk of congenital anomalies (CAs) in infants conceived by infertile women through assisted reproductive technology (ART). A total of 9,013 clinical pregnancy cycles resulting in 9,101 live births between 2004 and 2014 were analysed. Congenital anomalies were evaluated and compared with spontaneous pregnancies in infertile women. A total of 9,101 infants were born following ART. Three subgroups were established: In vitro fertilisation fresh embryo transfer (IVF-ET), n=2,919, intracytoplasmic sperm injection fresh embryo transfer (ICSI), n=1,996 and frozen-thawed embryo transfer (FET), n=4,186. No significant differences in perinatal outcomes were observed between the three subgroups. A total of 105 (1.15%) infants were born with CAs. The birth defect rate was slightly higher in the IVF-ET subgroup compared with the other subgroups. Among infants in the IVF-ET and ICSI-ET subgroup, the probability of birth defects increased with increased maternal age (>35 years), male factors and diminished ovarian reserve. In the FET group, the risk of birth defects was significantly increased with multiple births and maternal age >35 years. The risk of congenital anomalies following ART was not significantly different compared with spontaneous conceptions within the infertile study population. The results of the present study may provide guidance for patients who are considering treatment for infertility in China.

Paternal age and assisted reproductive technology: problem solver or trouble maker?

In our society, the number of couples with advanced reproductive age seeking fertility treatment is increasing steadily. While the negative effect of female age on assisted reproductive technology (ART) outcomes is well established, the impact of paternal age needs to be clarified. We reviewed the current literature to determine whether advanced paternal age affects the results of ART and the health of resulting offspring. We found that the published literature is overall supportive of a positive association between advanced paternal age (>40 years) and semen quality deterioration. However, the existing evidence does not corroborate nor discard the influence of advanced paternal age on ART outcomes. Similarly, the effect of paternal age on the health of ART offspring remains equivocal, although data from naturally-conceived children clearly indicates that advanced paternal age increases the frequency of genetic, neurodevelopmental, and psychiatric diseases in the progeny. Noteworthy, the current literature is limited and subjected to bias due to the impact of maternal age as a critical confounder. Health care providers should discuss with concerned couples the available options to counteract the possible negative influence of advanced paternal age on ART outcomes and health of resulting offspring. These include identification and treatment of underlying conditions with potential negative long-term effects on fertility, sperm freezing at a young age, and use of antioxidant supplements for men at risk of excessive oxidative stress. Aged male partner from couples undergoing ART, in particular men of 50 years and older, should consider use of preimplantation genetic testing as a means to detect embryo abnormalities and select euploid embryos for transfer to the uterine cavity.

Dynamic assessment of human sperm DNA damage I: the effect of seminal plasma-sperm co-incubation after ejaculation

AIM

The purpose of the study was to evaluate the impact of seminal plasma in human ejaculates on the sperm DNA quality and DNA longevity.

METHODS

Semen samples for this study were obtained from 20 donors with a normal spermiogram. Following centrifugation, the sperm pellet was resuspended either in the seminal plasma proceeding from its respective donor, or in an equal amount of PBS, adjusting the concentration to 50 × 10⁶/ml. Each set of samples was incubated at 37 °C for 24 h and the sperm DNA damage was assessed using the chromatin-dispersion test following 0, 2, 6, and 24 h of incubation.

RESULTS

Sperm DNA fragmentation (SDF) did not differ between the two experimental conditions at T0; however, Kaplan-Meier estimates to test for survival showed an statistical significant increase of SDF in the seminal plasma group when compared to the PBS group following all timeframes (p 0.000). With respect to sperm DNA longevity, the most dramatic loss of sperm DNA quality occurred during the first 2 h of incubation, with the rate of SDF (rSDF) in the seminal plasma being 2.1 more intense than in PBS. Interestingly, the rSDF was found to vary significantly between individuals, which was confirmed with significant correlations in all rSDF timeframes (rSDF T0-2, p 0.049; rSDF T2-6, p 0.000; rSDF T6-24: p 0.000).

CONCLUSIONS

Co-incubation of semen samples in seminal plasma after ejaculation increases iatrogenic sperm damage. This effect is statistically significant after 2 h of co-incubation. Subsequently, for ART purposes seminal plasma must be quickly removed after ejaculation-liquefaction, to avoid a higher susceptibility of sperm DNA towards fragmentation.

Beckwith Wiedemann syndrome: A population-based study on prevalence, prenatal diagnosis, associated anomalies and survival in Europe

Beckwith Wiedemann syndrome is a complex developmental disorder characterized by somatic overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycemia, and predisposition to embryonal tumors. We present epidemiological and clinical aspects of patients with Beckwith Wiedemann syndrome diagnosed prenatally or in the early years of life, using data from EUROCAT (European Surveillance of Congenital Anomalies) registries. The study population consisted of 371 cases identified between January 1990 and December 2015 in 34 registries from 16 European countries. There were 15 (4.0%) terminations of pregnancy after prenatal detection of severe anomaly/anomalies, 10 fetal deaths (2.7%), and 346 (93.3%) live-births. Twelve (3.6%) of the 330 live-births with available information on survival died in the first week of life, of those eleven (91.6%) were preterm. First-year survival rate was 90.9%. Prematurity was present in 40.6% of males and 33.9% of females. Macrosomia was found in 49.2% and 43.3% of preterm males and females, respectively. Of term newborns, 41.1% of males and 24% of females were macrosomic. Out of 353 cases with known time of diagnosis, 39.9% were suspected prenatally, 36.3% at birth, 7.6% were diagnosed in the first week of life, and 16.2% in the first year of life. The mean gestational age at prenatal diagnosis by obstetric ultrasound was 19.8 ± 6.2 (11-39) gestational weeks. The mean prenatal diagnosis of cases where parents opted for termination of pregnancy was 15.3 ± 2.4 (11-22) gestational weeks, and the mean gestational age at termination was 19.3 ± 4.1 (13-26) gestational weeks. The prenatal detection rate was 64.1% (141/220) with no significant change over time. There were 12.7% of familial cases. The study confirmed the association of assisted reproductive technologies with Beckwith Wiedemann syndrome, as 7.2% (13/181) of patients were conceived by one of the methods of assisted reproductive technologies, which was three times higher compared to the general population of the countries included in the study. Twin pregnancies of undetermined zygosity were recorded in 5.7% (21/365) cases, and were on average three to four times more common than in European countries that participated in the study. The estimated mean prevalence of classical Beckwith Wiedemann syndrome in Europe was 3.8 per 100,000 births or 1:26,000 births.

Investigation on the origin of sperm morphological defects: oxidative attacks, chromatin immaturity, and DNA fragmentation

DNA fragmentation can be deleterious on spermatozoon morphology but the pathogenesis of teratozoospermia associated with DNA breaks is not fully understood, even if oxidative attacks and defects in chromatin maturation are hypothesized. Therefore, this study is one of the first to clarify on the underlying hypothesizes behind such observations. The objectives of our study were to assess the role of oxidative attacks in DNA damage pathogenesis in ejaculated spermatozoa from patients with isolated teratozoospermia. We aimed to assess the correlation of DNA breaks with morphologically abnormal spermatozoa, as well as ROS level and impairment chromatin condensation. A total of 90 patients were divided into two groups, men with isolated teratozoospermia (n = 60) and men with normal semen parameters (n = 30) as controls. DNA fragmentation was evaluated by TUNEL assay; chromatin immaturity was studied using acridine orange and toluidine blue staining. We evaluated the ability of spermatozoa to produce reactive oxygen species with nitro blue tetrazolium staining. Patient with teratozoospermia when compared to fertile men showed significantly higher rates of semen ROS production, sperm hypocondensated chromatin, denaturated DNA, and fragmented DNA. All these parameters were positively correlated with abnormal sperm morphology. The studied DNA integrity markers were also correlated with ROS production. Fragmented DNA is the main pathway leading to morphology defects in the sperm. In fact, impaired chromatin compaction may induce DNA breaks and free radicals, which can break the DNA backbone indirectly, by reducing protamination and disulphide bond formation, as oxidative attack appears to be the major cause of poor semen morphology.

The effect of human sperm chromatin maturity on ICSI outcomes

Because sperm chromatin may play a key role in reproductive success, we verify the associations between sperm chromatin abnormalities, embryo development and the ability to achieve pregnancy. The evaluation of sperm chromatin maturity using aniline blue (AB), chromomycin A3 (CMA3) and toluidine blue (TB) staining were carried out in group of males from infertile couples that underwent ICSI. Low levels of sperm chromatin abnormalities (< 16%) were found in most subjects (> 50%). A higher percentage of TB-positive sperm cells were discovered in the men from couples who achieved ≤ 50% fertilized oocytes compared to men who achieved > 50%. No significant differences were discovered by the applied tests between the men from couples who achieved ≤ 50% and those who achieved > 50% high-quality embryos on the 3rd or 5th day after fertilization, nor between the men from couples who achieved pregnancy and those who failed. The sperm chromatin maturity did not correlate with the ICSI results. However, the ROC analysis revealed a significant predictive value of TB-positive spermatozoa only for fertilization. Therefore, the TB assay can be considered as a useful test for the prediction of fertilization. Our findings suggest that the level of sperm chromatin abnormalities of the examined men was not clinically significant. No found associations between sperm chromatin maturity and embryo development and the ability to achieve pregnancy. We could not exclude the effects of the repairing processes in the fertilized oocyte. The use of complementary tests that verify the status of the sperm chromatin seems justified.

Live births from artificial insemination of microfluidic-sorted bovine spermatozoa characterized by trajectories correlated with fertility

Selection of functional spermatozoa plays a crucial role in assisted reproduction. Passage of spermatozoa through the female reproductive tract requires progressive motility to locate the oocyte. This preferential ability to reach the fertilization site confers fertility advantage to spermatozoa. Current routine sperm selection techniques are inadequate and fail to provide conclusive evidence on the sperm characteristics that may affect fertilization. We therefore developed a selection strategy for functional and progressively motile bovine spermatozoa with high DNA integrity based on the ability to cross laminar flow streamlines in a diffuser-type microfluidic sperm sorter (DMSS). The fluid dynamics, with respect to microchannel geometry and design, are relevant in the propulsion of spermatozoa and, consequently, ultrahigh-throughput sorting. Sorted spermatozoa were assessed for kinematic parameters, acrosome reaction, mitochondrial membrane potential, and DNA integrity. Kinematic and trajectory patterns were used to identify fertility-related subpopulations: the rapid, straighter, progressive, nonsinuous pattern (PN) and the transitional, sinuous pattern (TS). In contrast to the conventional notion that the fertilizing spermatozoon is always vigorously motile and more linear, our results demonstrate that sinuous patterns are associated with fertility and correspond to truly functional spermatozoa as supported by more live births produced from predominant TS than PN subpopulation in the inseminate. Our findings ascertain the true practical application significance of microfluidic sorting of functional sperm characterized by sinuous trajectories that can serve as a behavioral sperm phenotype marker for fertility potential. More broadly, we foresee the clinical application of this sorting technology to assisted reproduction in humans.

Paternal age: Negative impact on sperm genome decays and IVF outcomes after 40 years

This study assessed sperm quality declining on relation to paternal age and its impact on in vitro fertilization (IVF) outcomes in order to estimate the APA (Advanced Paternal Age) cutoff. For this, 83 couples undergoing IVF treatment for male factor infertility were enrolled. The women age was ≤39 years, whereas the men were divided in two groups: APA (n = 41; age ≥ 40 years) and young (Y) (n = 42; age < 40 years). Conventional semen parameters (volume, concentration, motility, vitality, and morphology) were analyzed in the collected sperm samples. Furthermore, sperm genome decays (SGD) was assessed by TUNEL assay (DNA fragmentation), aniline blue staining (chromatin decondensation), and fluorescent in situ hybridization (aneuploidy). No significant difference was found concerning the conventional semen parameters between APA and Y groups. Conversely, SGD analysis showed increased DNA fragmentation; chromatin decondensation and sperm aneuploidy rates in the APA group (respectively, 41%, 43%, and 14% vs. 25%, 23%, and 4% in Y group). IVF outcomes also were affected by paternal age as indicated by the rates of cancelled embryo transfers, clinical pregnancy and miscarriage in the two groups APA and Y (29%, 17%, and 60% vs. 10%, 32%, and 42%). Finally, statistical analysis of the results suggests that the age of 40 should be considered as the APA cutoff during ART attempts.

Role of sperm DNA fragmentation in male factor infertility: A systematic review

OBJECTIVE

To summarise the latest evidence on the role of sperm DNA fragmentation (SDF) in male factor infertility, as SDF has been emerging as a valuable tool for male infertility evaluation.

METHODS

A search of PubMed was conducted using the keywords 'sperm DNA fragmentation' and 'male infertility'. Studies in languages other than English were excluded. All identified studies were screened and clinical studies in humans were included.

RESULTS

In all, 150 articles were included for analysis. Current evidence supports the association between high SDF and poor reproductive outcomes for natural conception and intrauterine insemination. Although the relationship between high SDF and in vitro fertilisation and intracytoplasmic sperm injection is less clear, the negative implication of high SDF on pregnancy loss is evident. Various treatment strategies have been attempted with varying success. The predictive value of SDF testing on outcomes of natural pregnancy and assisted reproduction illustrates its value in clinical practice.

CONCLUSION

The significant role of SDF in male factor infertility is supported by current evidence. The beneficial role of SDF testing in selection of varicocelectomy candidates, evaluation of patients with unexplained infertility and recurrent pregnancy loss, selection of the most appropriate assisted reproductive technique with highest success rate for infertile couples, and assessment of infertile men with modifiable lifestyle factors or gonadotoxin exposure has been recently proposed.

Sperm selection by thermotaxis improves ICSI outcome in mice

The ejaculate is a heterogeneous pool of spermatozoa containing only a small physiologically adequate subpopulation for fertilization. As there is no method to isolate this subpopulation, its specific characteristics are unknown. This is one of the main reasons why we lack effective tools to identify male infertility and for the low efficiency of assisted reproductive technologies. The aim of this study was to improve ICSI outcome by sperm selection through thermotaxis. Here we show that a specific subpopulation of mouse and human spermatozoa can be selected in vitro by thermotaxis and that this subpopulation is the one that enters the fallopian tube in mice. Further, we confirm that these selected spermatozoa in mice and humans show a much higher DNA integrity and lower chromatin compaction than unselected sperm, and in mice, they give rise to more and better embryos through intracytoplasmic sperm injection, doubling the number of successful pregnancies. Collectively, our results indicate that a high quality sperm subpopulation is selected in vitro by thermotaxis and that this subpopulation is also selected in vivo within the fallopian tube possibly by thermotaxis.

Sperm DNA fragmentation in donors and normozoospermic patients attending for a first spermiogram: Static and dynamic assessment

Static assessment of sperm DNA Fragmentation (SDF at the time of ejaculation or sperm thawing when cryopreserved) and the dynamic assessment of SDF (SDF assessed after T2 hr, T6 hr and T24 hr of sperm thawing) were used to establish cut-off values associated with sperm donors when compared with closely related normozoospermic patients. Cryopreserved samples from donors revealed SDF levels two times lower in comparison with the patients. Donor sperm DNA exhibited a 2.5 times higher longevity when compared with the patients. Static values of SDF after thawing of approximately 11% identify the donors with a 71% of sensitivity and 84% specificity. With respect to the dynamic assessment, SDF increases of 2.3 per hr during the first 2 hr of incubation identify the donors with 70% of sensitivity and 66% of specificity. Creating the Rate of Combined Damage (RCD) defined as the product of SDF-T0 by the increase in the damage registered during the first 2 hr of incubation (r-SDF-T0-2 ), an index of RCD = 22.2 units has an identification capacity of donors with a 78% sensitivity and 77% specificity. Such cut-off values could be used to characterise donors with high chromatin resistance to damage when meeting the above-established criteria.

Effects of boar variability on comet-detected sperm-DNA damage following cryopreservation

Assessment of sperm-DNA integrity is a crucial issue in male fertility. In the present study, parameters derived from the image analysis of comets after single-cell gel electrophoresis were used to analyse the types of DNA damage of frozen–thawed boar spermatozoa. Semen, frozen in a cryoprotectant-free extender or in cryoprotectant-based extenders, was analysed for DNA fragmentation and with the following comet tail measures: percentage DNA in comet tail, comet tail length and olive tail moment. The percentages of sperm DNA damage in the comet tails were classified as Type 0 (no DNA damage), Type I (very low DNA damage), Type II (light DNA damage), Type III (medium DNA damage) and Type IV (heavy DNA damage). Sperm motility characteristics and membrane integrity were assessed in the pre-freeze and frozen–thawed semen samples. Assessment of sperm DNA fragmentation and comet tail measures showed marked inter-boar variability following cryopreservation. However, consistent differences among the boars, with respect to cryo-induced sperm DNA damage, were detected by the comet tail length and olive tail moment. Besides Type IV, all types of DNA damage were detected in the cryoprotectant-based extenders. It was found that the frequency of Type II and Type III of DNA damage of frozen–thawed spermatozoa was significantly greater in the cryoprotectant-based and cryoprotectant-free extenders respectively. Deterioration in the quality of the sperm DNA integrity was concomitant with a marked decline in sperm motility characteristics, reduced plasma membrane integrity and higher lipid peroxidation and aspartate aminotransferase activity after cryopreservation. It can be suggested that the comet-assay parameters, coupled with routine laboratory tests, are useful to improve the sperm evaluations of post-thaw quality of semen from individual boars and would offer more comprehensive information for a better understanding of the degree of cryo-induced sperm-DNA damage.

Effect of bovine sperm chromatin integrity evaluated using three different methods on in vitro fertility

In vitro fertility potential of individual bulls is still relatively uncharacterized. Classical sperm analysis does not include the evaluation of all sperm characteristics and thus, some cell compartments could be neglected. In humans, sperm DNA integrity has already proven to have major influence in embryo development and assisted reproduction techniques successfully. In bovine, some studies already correlated chromatin integrity with field fertility. However, none of those have attempted to relate DNA assessment approaches such as chromatin deficiency (CMA3), chromatin stability (SCSA; AO+) and DNA fragmentation (COMET assay) to predict in vitro bull fertility. To this purpose, we selected bulls with high and low in vitro fertility (n = 6/group), based on embryo development rate (blastocyst/cleavage rate). We then performed CMA3, SCSA test and COMET assay to verify if the difference of in vitro fertility may be related to DNA alterations evaluated by these assays. For the three tests performed, our results showed only differences in the percentage of cells with chromatin deficiency (CMA3+; high: 0.19 ± 0.03 vs low: 0.04 ± 0.04; p = 0.03). No difference for chromatin stability and any of COMET assay categories (grade I to grade IV) was observed between high and low in vitro fertility bulls. A positive correlation between AO + cells and grade IV cells was found. Despite the difference between groups in CMA3 analysis, our results suggest that protamine deficiency in bovine spermatozoa may not have a strong biological impact to explain the difference of in vitro fertility between the bulls used in this study.

Combined advanced parental age has an additive negative effect on live birth rates-data from 4057 first IVF/ICSI cycles

PURPOSE

The purpose of this study is to determine if there is an additive effect of combined advanced maternal and paternal age on pregnancy and live birth rates.

METHODS

Retrospective data analysis of 4057 first cycles at a fertility centre between 2009 and 2013 was compiled. Donor, preimplantation genetic screening and double embryo transfer cycles were excluded. Main outcomes measured were clinical pregnancy, viable pregnancy, live birth and term birth.

RESULTS

Logistic regression indicated strong negative associations for maternal ages exceeding 27 years with clinical pregnancies (p < 0.001), viable pregnancies (p < 0.001), live births (p < 0.001) and term births (p < 0.001). There was evidence of negative associations between paternal age and both viable pregnancies (p = 0.06) and live births (p = 0.04), such that the probability of pregnancy was 10% further reduced for women who were 35 years with a partner over 40 years vs. women aged 35 years with a partner under 30 years. There was evidence of an interaction between maternal age and the paternal age on term births (p = 0.02) such that advanced paternal age's effect on the probability of a term birth was only evident in couples where the maternal age ranged between ~27 and 35 years.

CONCLUSIONS

There is an additive effect to pregnancy and live birth rates when both partners are of an advanced age, thus highlighting the need for pre-conception public health messaging and a combined approach to ART counselling assessing both parental ages in combination.

Sperm DNA fragmentation testing: a cross sectional survey on current practices of fertility specialists

Background

Sperm DNA fragmentation (SDF) testing has been recognized as a valuable tool in the evaluation of infertile men. Despite that, its routine use in clinical practice is still hampered by the lack of understanding of the specific clinical scenarios where SDF testing is most beneficial. The aim of this study was to investigate fertility specialists evaluation of infertility of SDF testing in the context of male infertility evaluation and assisted reproductive technology.

Methods

A questionnaire was developed to survey the major aspects of SDF testing and was mailed to specialists with demonstrated clinical experience in the field of infertility. A total of 65 professionals were invited to answer issues related to the utility of SDF testing, the testing methods they used, were the SDF cut-off values, and the cost of testing and the perceived drawbacks of the test results. Specific clinical scenarios were presented to assess whether or not participants would recommend SDF testing. The frequency of responses was analyzed.

Results

Forty-nine participants from 19 countries responded to the study questionnaire. SDF testing was commonly ordered by 39 (79.6%) respondents; while 10 (20.4%) did not order SDF testing during fertility evaluation. Terminal deoxynucleotidyl transferase nick end labelling (TUNEL) and sperm chromatin structure assay (SCSA) were most commonly utilized (30.6% for both), followed by sperm chromatin dispersion (SCD) (20.4%), single cell gel electrophoresis (Comet) (6.1%) and other methods (12.2%). SDF was most commonly requested in couples presenting with recurrent conventional in vitro fertilization (IVF) failure or pregnancy loss following conventional IVF (91.8%), followed by couples with recurrent first trimester natural pregnancy loss (NPL) and recurrent pregnancy loss (RPL) following intracytoplasmic sperm injection (ICSI) (85.7% for both). A 67.3% of respondents admitted that an SDF test result would affect their decision to utilize testicular instead of ejaculated sperm for ICSI. The reported mean ± standard deviation (SD) cost (USD) of SDF testing was 170.4±122.9. Cost (46.9%), poor validation (36.7%) and low precision (18.3%) were the most commonly reported drawbacks of SDF testing.

Conclusions

SDF testing is utilized in the evaluation of infertility patients by a majority of fertility specialists under specific clinical scenarios. Shortcomings, such as the presence of several SDF testing methods with different cut-off values and the test charges were some of the reasons hampering the routine use of SDF in the evaluation of infertile men.

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

Background

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

Methods

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

Results

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

Conclusions

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

Elevated aminopeptidase N affects sperm motility and early embryo development

Aminopeptidase N (APN) is a naturally occurring ectopeptidase present in mammalian semen. Previous studies have demonstrated that APN adversely affects male fertility through the alteration of sperm motility. This enzyme constitutes 0.5 to 1% of the seminal plasma proteins, which can be transferred from the prostasomes to sperms by a fusion process. In the present study, we investigated the molecular mechanism of action of APN and its role in regulating sperm functions and male fertility. In this in vitro study, epididymal mouse spermatozoa were incubated in a capacitating media (pH 7) containing 20 ng/mL of recombinant mouse APN for 90 min. Our results demonstrated that the supplementation of recombinant APN in sperm culture medium significantly increased APN activity, and subsequently altered motility, hyperactivated motility, rapid and medium swimming speeds, viability, and the acrosome reaction of mouse spermatozoa. These effects were potentially caused by increased toxicity in the spermatozoa. Further, altered APN activity in sperm culture medium affected early embryonic development. Interestingly, the effect of elevated APN activity in sperm culture medium was independent of protein tyrosine phosphorylation and protein kinase A activity. On the basis of these results, we concluded that APN plays a significant role in the regulation of several sperm functions and early embryonic development. In addition, increased APN activity could potentially lead to several adverse consequences related to male fertility.

Comet assay on thawed embryos: An optimized technique to evaluate DNA damage in mouse embryos

Our objective was to optimize the CA technique on mammal embryos.

MATERIALS AND METHODS

1000 frozen 2-cell embryos from B6CBA mice were used. Based on a literature review, and after checking post-thaw embryo viability, the main outcome measures included: 1) comparison of the embryo recovery rate between 2 CA protocols (2 agarose layers and 3 agarose layers); 2) comparison of DNA damage by the CA on embryos with (ZP+) and without (ZP-) zona pellucida; and 3) comparison of DNA damage in embryos exposed to 2 genotoxic agents (H₂O₂ and simulated sunlight irradiation (SSI)). DNA damage was quantified by the % tail DNA.

RESULTS

1) The recovery rate was 3,3% (n=5/150) with the 2 agarose layers protocol and 71,3% (n=266/371) with the 3 agarose layers protocol. 2) DNA damage did not differ statistically significantly between ZP- and ZP+ embryos (12.60±2.53% Tail DNA vs 11.04±1.50 (p=0.583) for the control group and 49.23±4.16 vs 41.13±4.31 (p=0.182) for the H₂O₂ group); 3) H₂O₂ and SSI induced a statistically significant increase in DNA damage compared with the control group (41.13±4.31% Tail DNA, 36.33±3.02 and 11.04±1.50 (p<0.0001)). The CA on mammal embryos was optimized by using thawed embryos, by avoiding ZP removal and by the adjunction of a third agarose layer.

"Bone Development" Is an Ontology Group Upregulated in Porcine Oocytes Before In Vitro Maturation: A Microarray Approach

Mammalian cumulus-oocyte complexes (COCs) reach full developmental capability during folliculogenesis and oogenesis. It is well recognized that only gametes achieving MII stage after in vivo or in vitro maturation (IVM) are successfully fertilized by a single spermatozoon. Although the process of oocyte nuclear and/or cytoplasmic maturation in pigs is well determined, there exist many differences that promote these processes in vivo and in vitro. Therefore, this study aimed to investigate the differences in RNA expression profiles between porcine oocytes before and after IVM using microarray and real-time quantitative polymerase chain reaction (RT-qPCR) assays. Experiments were performed on oocytes isolated from 55 pubertal crossbred Landrace gilts. The oocytes were analyzed both before and after IVM and only Brilliant Cresyl Blue (BCB)-positive gametes were used for subsequent microarray analysis (Affymetrix) and RT-qPCR analysis. The microarray assay, which measures expression of 12,258 transcripts, revealed 419 differentially expressed transcripts in porcine oocytes, from which 379 were downregulated and 40 were upregulated before IVM compared to those analyzed after IVM. After DAVID analysis, we found eight different transcripts, including IHH, BMP1, WWTR1, CHRDL1, KLF10, EIF2AK3, MMP14, and STC1. Their expression is related to the "bone development" ontology group and was further subjected to hierarchical clusterization. Using RT-qPCR analysis, we confirmed the results of the microarray assay, showing increased expression of the eight genes in oocytes before IVM compared to oocytes after maturation in vitro. It has been suggested that "bone development" belongs to one ontological group involving genes substantially upregulated in porcine oocytes before IVM. We suggest that the gamete mRNA expression profile before IVM may comprise stored transcripts, which are templates for protein biosynthesis following fertilization. We also hypothesize that these mRNAs may be a specific "fingerprint" of folliculogenesis and oogenesis in pigs.

Comparison of in vitro fertilization outcomes in ICSI cycles after human sperm preparation by density gradient centrifugation and direct micro swim-up without centrifugation

Objective

The aim of this study was to evaluate the efficacy of a non-expensive, easy and fast technique (direct micro swim-up) for sperm preparation in intracytoplasmic sperm injection (ICSI) treatments without the use of centrifuge.

Methods

We carried out a multicentric study in which a total of 140 ICSI-cycles were included. Sibling oocytes were divided into two groups according to semen preparation procedures: group A, discontinuous gradients (DG) (oocytes n=668), and group B, direct micro swim-up (MSU) (oocytes n=660). We analyzed differences in some key performance indicators.

Results

Fertilization rates were not statistically different between the DG and MSU groups (76.0% vs. 81.8%, respectively, p=0.248); while significant differences were found in blastulation rates per fertilized oocytes (41.7% vs. 58.5%, p=0.009), blastulation rates per D3 embryos (46.1% vs. 63.7%, p=0.045), and pregnancy rates (25.8% vs. 41.9%, p=0.045). The abortion rate was reduced in the MSU group as compared to DG, but not in a significant manner (12.9% vs. 29.4%, p=0.161).

Conclusion

The MSU procedure has the advantage of reducing costs, time and mismatches, while ensuring comparable, and in some cases, better results than DG treatments. This technique can therefore be used as an alternative method to other conventional semen treatments.

A systematic review and meta-analysis to determine the effect of sperm DNA damage on in vitro fertilization and intracytoplasmic sperm injection outcome

Sperm DNA damage is prevalent among infertile men and is known to influence natural reproduction. However, the impact of sperm DNA damage on assisted reproduction outcomes remains controversial. Here, we conducted a meta-analysis of studies on sperm DNA damage (assessed by SCSA, TUNEL, SCD, or Comet assay) and clinical pregnancy after IVF and/or ICSI treatment from MEDLINE, EMBASE, and PUBMED database searches for this analysis. We identified 41 articles (with a total of 56 studies) including 16 IVF studies, 24 ICSI studies, and 16 mixed (IVF + ICSI) studies. These studies measured DNA damage (by one of four assays: 23 SCSA, 18 TUNEL, 8 SCD, and 7 Comet) and included a total of 8068 treatment cycles (3734 IVF, 2282 ICSI, and 2052 mixed IVF + ICSI). The combined OR of 1.68 (95% CI: 1.49–1.89; P < 0.0001) indicates that sperm DNA damage affects clinical pregnancy following IVF and/or ICSI treatment. In addition, the combined OR estimates of IVF (16 estimates, OR = 1.65; 95% CI: 1.34–2.04; P < 0.0001), ICSI (24 estimates, OR = 1.31; 95% CI: 1.08–1.59; P = 0.0068), and mixed IVF + ICSI studies (16 estimates, OR = 2.37; 95% CI: 1.89–2.97; P < 0.0001) were also statistically significant. There is sufficient evidence in the existing literature suggesting that sperm DNA damage has a negative effect on clinical pregnancy following IVF and/or ICSI treatment.

Predictive value of sperm deoxyribonucleic acid (DNA) fragmentation index in male infertility

Background

Recently, damage to the sperm DNA has been studied as it is associated with reduced fertilization rates, embryo quality, and pregnancy rates, also higher rates of spontaneous miscarriage.

Objective

To develop a diagnostic method in predicting male infertility.

Material and Methods

The design of this study is cross-sectional. Data were retrieved from medical records of Yasmin IVF Clinic Dr. Cipto Mangunkusumo General Hospital and Daya Medika Infertility Clinic from January to December 2015. Subjects were selected by consecutive sampling and divided into two groups: infertile and fertile. Sperm deoxyribonucleic acid fragmentation index (DFI) was determined by sperm chromatin dispersion (SCD) method using Halosperm® Kit.

Results

There were 114 subjects (36 fertile and 78 infertile) selected into this study. We found no significant difference in the age between both of groups. The median value of sperm DFI in infertile group was significantly higher, 29.95 (26.6–34.3)%, compared to 19.90 (15.6–24.4)% of the fertile group, with p < 0.001. Area Under Curve (AUC) of sperm DFI, 0.862 (95% CI 0.783, 0.941), was higher than concentration (AUC 0.744; 95% CI 0.657, 0.831), motility (AUC 0.668; 95% CI 0.572, 0.765), and morphology (AUC 0.718; 95% CI 0.697, 0.864) of the semen analysis. At the cut-off point of 26.1%, the sperm DFI had sensitivity of 80.8% (95% CI; 70.0, 88.5), specificity of 86.1% (95% CI; 69.7, 94.8), positive predictive value (PPV) of 92.6% (95% CI; 83.0, 97.3), negative predictive value (NPV) of 67.4% (95% CI; 51.9, 80.0), positive likelihood ratio (PLR) of 12.6 (95% CI; 5.4, 29.4), and negative likelihood ratio (NLR) of 0.48 (95% CI 0.31, 0.75). Sperm DFI of ≥26.1% had prevalence ratio of 2.84 (95% CI 1.86, 4.33) for the occurrence of male infertility.

Conclusion

There was significant difference between the median value of sperm DFI of infertile men and fertile men. Compared to semen analysis, sperm DFI at cut-off point of 26.1% has a higher diagnostic value (AUC).