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Obesity is a chronic health problem associated with severe complications and with an increasing prevalence in the Western world. Body-fat composition and distribution are closely associated with obesity, but the human body’s composition is a sexually dimorphic trait, as differences between the two sexes are evident even from fetal life. The effect of sex hormones contributes to this phenomenon. However, studies investigating gene-by-sex interactions for obesity are limited. Therefore, the aim of the present study was to identify single-nucleotide polymorphisms (SNPs) associated with obesity and overweight in a male population. A genome-wide association study (GWAS) that included 104 control, 125 overweight, and 61 obese subjects revealed four SNPs associated with overweight (rs7818910, rs7863750, rs1554116, and rs7500401) and one SNP (rs114252547) associated with obesity in males. An in silico functional annotation was subsequently used to further investigate their role. Most of the SNPs were found in genes regulating energy metabolism and homeostasis, and some of them were expression quantitative trait loci (eQTL). These findings contribute to the understanding of the molecular mechanisms underlying obesity-related traits, especially in males, and pave the road for future research toward the improvement of the diagnosis and therapy of obese individuals.

Male infertility is a global health problem that affects a large number of couples worldwide. It can be categorized into specific subtypes, including teratozoospermia. The present study aimed to identify new variants associated with teratozoospermia in the Greek population and to explore the role of genes on which these were identified. For this reason, whole-genome sequencing (WGS) was performed on normozoospermic and teratozoospermic individuals, and after selecting only variants found in teratozoospermic men, these were further prioritized using a wide range of tools, functional and predictive algorithms, etc. An average of 600,000 variants were identified, and of them, 61 were characterized as high impact and 153 as moderate impact. Many of these are mapped in genes previously associated with male infertility, yet others are related for the first time to teratozoospermia. Furthermore, pathway enrichment analysis and Gene ontology (GO) analyses revealed the important role of the extracellular matrix in teratozoospermia. Therefore, the present study confirms the contribution of genes studied in the past to male infertility and sheds light on new molecular mechanisms by providing a list of variants and candidate genes associated with teratozoospermia in the Greek population.

Male infertility is a global health problem that affects a large number of couples worldwide. It can be categorized into specific subtypes, including teratozoospermia. The present study aimed to identify new variants associated with teratozoospermia in the Greek population and to explore the role of genes on which these were identified. For this reason, whole-genome sequencing (WGS) was performed on normozoospermic and teratozoospermic individuals, and after selecting only variants found in teratozoospermic men, these were further prioritized using a wide range of tools, functional and predictive algorithms, etc. An average of 600,000 variants were identified, and of them, 61 were characterized as high impact and 153 as moderate impact. Many of these are mapped in genes previously associated with male infertility, yet others are related for the first time to teratozoospermia. Furthermore, pathway enrichment analysis and Gene ontology (GO) analyses revealed the important role of the extracellular matrix in teratozoospermia. Therefore, the present study confirms the contribution of genes studied in the past to male infertility and sheds light on new molecular mechanisms by providing a list of variants and candidate genes associated with teratozoospermia in the Greek population.

Study question How demanding in terms of time and resource allocation is the full integration of an AI platform to the routine operation of an IVF clinic? Summary answer The rapid and effective implementation, and continuous performance, of EMA was qualitatively and quantitatively demonstrated for the first time in a real-world clinical setting. What is known already The role of AI-based embryo predictive analysis tools is often hailed as one of the most important recent developments in the IVF clinic. The high precision of such systems has been reported. For instance, the AI-system implemented here, EMATM(AiVF), employs a convolutional neural network architecture, providing an area-under-the-curve (AUC) of 0.95 with 83% accuracy. However, little was reported to date on the full implementation of these advanced systems in the active IVF lab. This study prospectively evaluated the clinical implementation and process-of-use in an IVF clinic of EMA, the first end-to-end AI-driven platform designed to algorithmically aid in evaluating embryos. Study design, size, duration A prospective observational single center study. The study was performed in two phases. Phase I: EMA was integrated into standard workflow and qualitatively evaluated over the course of one month by five embryologists in a series of twice-daily qualitative checks and questionaries. Phase II: The rate of agreement between EMA and embryologists were benchmarked and compared to evaluate how the model aids embryologists in efficiently assessing embryos. Participants/materials, setting, methods Phase I: Five senior embryologists completed electronic questionaries to qualitatively report on the ease-of-use, functionality, and performance of EMA after using the platform as adjunctive information on 588 embryos; ICSI was performed on all treatment cycles. Phase I was completed within 2 weeks. Phase II: The rate of agreement between five senior embryologists and EMA was calculated for the accuracy in ranking embryo(s) for transfer/freeze (146 treatment cycles). Phase II was undertaken in 4 weeks. Main results and the role of chance EMA was effectively incorporated into a busy IVF laboratory for routine daily use to algorithmically assess all embryos at 105 hours post-fertilization prior to vitrification. All embryos were cultured in a time-lapse incubator and successfully evaluated by both EMA and embryologists in parallel to conventional morphologic embryo evaluation. In Phase I, all five embryologists qualitatively approved of EMA’s integration and clinical utility inside their workflow and reported enhanced efficiency when EMA was used per its intended use. In Phase II we demonstrated a 86% agreement rate between embryologists and EMA. Of all embryos selected for transfer by embryologists 100% were also identified by EMA as having the highest potential for implantation. Of all embryos selected for vitrification by embryologists, 85%were identified by EMA as top-quality (Gardner criteria: A/B grade) embryos. Among embryos that were graded C/D (Gardner criteria) by embryologists, 89% were identified by EMA as “low grade” as well. Pregnancies were shown to be highly associated with EMA's embryo selection. The final stage of our implementation analysis of EMA is currently ongoing; the association between the algorithmic outputs of EMA and clinical implantation rates are being investigated in a prospective double-blinded, observation cohort study and results will be presented. Limitations, reasons for caution This is a single center study, based on relatively homogenous patient population. Nevertheless, given the impressive results reported herein, we conclude that this single case-study is sufficient for demonstrating rapid and successful implementation and process-validation of EMA for routine use by the clinic. Wider implications of the findings AI-based decision support systems like EMA have the potential to increase rapid and objective standardization inside the clinic, thereby improving accurate decision making and saving time and resources without interfering with the busy workflow of an IVF setting. Routine use of EMA in IVF should be prioritized for further evaluation. Trial registration number N/A

Study question Can embryo culture in 3% O2 concentration improve fertilization and blastocyst formation rates, as well as euploidy rate, compared to 5% O2 embryo culture? Summary answer Ultra-low oxygen concentration (3%) does not seem to improve fertilization and euploidy rate neither embryo quality and blastocyst formation rate. What is known already Low oxygen tension (5%) during embryo culture has found to be beneficial for embryo development, when compared to atmospheric O2 tension (20%). Physiologically, oxygen tension is decreasing from ∼5% in the fallopian tube to ∼2,5% in the uterus and embryos enter the uterus on the post-compaction stage, around Day 4 of their development. Additionally, our previous study demonstrated that euploidy rate was significantly higher in 5% O2 concentration compared to 20%. Thus, the purpose of this study was to evaluate whether culture of embryos to blastocyst stage could benefit from a decrease in O2 concentration, from 5% to 3%. Study design, size, duration This retrospective study, included 176 PGT-A cycles, performed at Embryolab fertility clinic from May 2017 to November 2021. Two study groups were formed, in which oxygen tension was the only different parameter of culture conditions; the 5% O2 Group consisted of 114 PGT-A cycles resulting in 832 embryos and the 3% O2 Group with 62 PGT-A cycles including 479 embryos. Euploidy, fertilization and blastocyst formation rates were compared between the two groups. Participants/materials, setting, methods In all cycles included in the study, injected oocytes were incubated to either 3% O2 or 5% O2. The CO2 concentration was 6% in both groups. Embryos were cultured to blastocyst stage. In good quality available blastocysts (expansion: >3, ICM: A/B, TE: A/B according to Gardner Grading System), trophectoderm biopsy was performed on Days 5/6 and embryos were analyzed for chromosomal abnormalities. All embryos were vitrified after biopsy. Statistical analysis was performed using Mann-Whitney test. Main results and the role of chance Mean female age was similar between 5% and 3% group (37.76±4.7y vs 38.35±4.19y, p = 0.2263). Fertilization rates were similar between two groups (81.04% in 5% VS 81.77 in 3%, p = 0.9718). In 5% O2 Group, cleavage rate (98.86%) was found to be significantly higher, compared to 3% O2 Group (96.86%) (p = 0.003). Blastocyst formation rate (expressed per fertilized oocyte) was found to be significantly higher in the 5% O2 Group (76.56 in 5% VS 67.22 in 3%) (p = 0.029), as well as biopsied blastocyst rate (91.9% in 5% VS 82.29% in 3%) (p = 0.0056). Euploidy rates were found to be similar between the two groups, 26.7 in 5% Group and 26.76 in 3% Group (p = 0.9272). However, more blastocysts were available for biopsy on Days 5/6 in the 5% Group, as shown above. In the 5% Group, 101 embryotransfers have been performed, 54 with positive βHCG and 42 cycles had no euploid embryos after PGT-A. In the 3% Group, 28 embryotransfers have been performed, 18 with positive βHCG, 7 cycles are pending and 24 had no euploid embryos. This is an ongoing study and clinical outcomes remain to be reported and analyzed after the completion of data selection. Limitations, reasons for caution This is a retrospective study in which cycles from the two groups were not performed simultaneously but at different time periods. In addition, all PGT-A cycles were included in the study, regardless the type of infertility (e.g. both male and non-male factor infertility). Wider implications of the findings Based on these results, it is not recommended to decrease oxygen tension below 5% during culture, as this does not improve fertilization and euploidy rates. Nevertheless, embryo quality and blastocyst formation was found to be higher in 5% Group and this findings should be confirmed in a larger sample size. Trial registration number not applicable

Study question Does laser assisted hatching (ΑΗΑ) of vitrified-warmed blastocysts post warming improve the pregnancy rates? Summary answer This study suggests that although laser assisted hatching post warming shows a trend towards improving pregnancy rates, the difference is not significant. What is known already It is known that vitrification may alter the zona pellucida’s biochemical properties and possibly cause hatching failure and ultimately implantation failure. One proposed way in order to overcome this drawback, is the implementation of laser assisted hatching. During assisted hatching, multiple laser shots are performed in the perivitelline space creating an opening on the zona pellucida which facilitates the blastocyst’s herniation process. The efficiency of this method in regard to pregnancy outcomes though, remains controversial. Some studies report a significantly positive effect on pregnancy outcomes using laser assisted hatching whereas others report no significant difference. Study design, size, duration This prospective randomized study was performed at Embryolab Fertility Clinic, in Thessaloniki, Greece between January 2020 and October 2020 and included 2439 frozen embryo transfers. Patients with vitrified-warmed embryos were randomized and allocated to the study (ΑHA) group or control (NO AHA) group. Participants/materials, setting, methods Patients were divided in two groups: AΗΑ group (n = 1799) where laser assisted hatching was performed on the day of embryotransfer (Day 3 or Day 5) on the zona of the embryos post warming and control group (n = 640) where the embryos remained untreated after the warming procedure. The 2 groups were further divided in 3 subgroups depending on the women’s’ age (≤35, 36-40, ≥41) and in 2 more subgroups depending on the day of the transfer. Main results and the role of chance Mean pregnancy rate for all embryos’ stages in AHA group was 60.03% whereas in the NO AHA group was 58.28% (p = 0.4385). In the subgroup of ≤ 35-years, pregnancy rates were 70.23% and 66.49% respectively (p = 0.3363). In the 36-40years subgroup, rates were 58.24% and 60.09% respectively (p = 0.6418). And finally, in the ≥41-years subgroup, pregnancy rates were 54.26% and 49.79% respectively (p = 0.2331). In the group where the embryos were on cleavage stage, the overall pregnancy rate for the AHA group was 27.46 and for the NO AHA group was 35.42% (p = 0.2957). In the subgroup of ≤ 35-years, pregnancy rates were 44.44% and 58.33% respectively (p = 0.4231). In the 36-40years subgroup, rates were 33.33% and 42.86% respectively (p = 0.5236). And finally, in the ≥41-years subgroup, pregnancy rates were 18.42% and 18.18% respectively (p = 0.9796). In the group where the embryos were on blastocyst stage, the overall pregnancy rate for the AHA group was 62.82% and for the NO AHA group was 60.14% (p = 0.2486). In the subgroup of ≤ 35-years, pregnancy rates were 71.66% and 67.03% respectively (p = 0.2430). In the 36-40years subgroup, rates were 60.16% and 61.31% respectively (p = 0.7786). And finally, in the ≥41-years subgroup, pregnancy rates were 58.37% and 53.08% respectively (p = 0.1763). Limitations, reasons for caution Clinical pregnancy rates and live birth rates were not available so as to draw a safer conclusion regarding the effectiveness of the method. In contrast to all kind of cases (both homologous and heterologous cycles) having been pooled together, an appropriate subgrouping might would have been the optimal approach. Wider implications of the findings AHA before transfer of vitrified/warmed embryos does not improve pregnancy rates regardless of stage or age. Nevertheless of the trend towards improving pregnancy rates, the difference is not statistically significant. Large scale, well-designed and appropriately subgrouped studies are necessary in order to investigate if this trend can become statistically significant. Trial registration number N/A

Study question Do double-vitrified embryos have impaired implantation potential compared to embryos vitrified once? Summary answer Double-vitrified embryos demonstrated significantly lower percentages of positive β-HCG, clinical pregnancy (CPR) and live birth (LBR) compared to embryos vitrified once. What is known already Since vitrification became a core player in ART, many clinics adopted a freeze-all strategy, including vitrification of more than one embryo per vitrification device. Nowadays, the guidelines’ suggestion for single embryo transfers often results in a surplus of good quality embryos post warming which are re-vitrified to avoid embryo wastage. Thus, transfers of double-vitrified embryos have been performed worldwide, leading to successful pregnancies. It remains yet to be answered whether embryos after double vitrification exhibit the same reproductive performance as embryos vitrified once. By now, limited studies including various cryopreservation methods show relatively conflicting results. Study design, size, duration This retrospective cohort study was conducted in Embryolab Fertility Clinic, Greece. Assisted reproductive cycles included in the study were performed from January 2015 to December 2020. Both PGT cycles and cryopreserved oocyte cycles were excluded. The mean women age was 32.8 years old (±5.9) in the study group and 33 (±5.9) in the control group. There was no variation in the cryopreservation methods used, since all embryos were cryopreserved by the same vitrification protocol. Participants/materials, setting, methods For the present study, 233 embryo transfers of 334 double-vitrified embryos (309 blastocysts/25 cleavage embryos) and 172 transfers of 260 embryos vitrified once (246 blastocysts/14 cleavage) were analyzed to explore the impact of double vitrification on positive β-HCG, CPR, LBR and miscarriage rate. Moreover, the performance of embryos that were cultured for at least 24 hours before re-vitrification was compared to embryos warmed and re-vitrified on the same day, for the same parameters mentioned above. Main results and the role of chance All embryos survived vitrification (100% survival rate) in both study and control group. An alpha level of .05 was used for all statistical tests. Results showed that positive β-HCG percentage was significantly lower in the double vitrification group (45.1% for double -vitrified embryos -study group-, 57.0% for embryos vitrified once -control group-, p=.02), as well as CPR (28.3% in study group - 42.4% in control group, p=.003) and LBR (26.6% in study group - 40.4% in control group, p=.004). The miscarriage rate did not significantly differ between two groups (35% in study group - 25% in control group, p=.121). Moreover, positive β-HCG percentage was significantly higher in transfers with embryos that were cultured at least 24 hours before re-vitrification (group A: 48.9%), compared to embryos that were warmed and re-vitrified on the same day (group B: 30.6%, p=.02). Interestingly, although CPR (31% in group A, 18.4% in group B, p=.08), LBR (29.4% in group A, 16.3% in group B, p=.06) and miscarriage rate (35.6% in group A, 33% in group B, p=.87) were not significantly different between these groups, there was a tendency for rates to be higher in group A compared to group B. Limitations, reasons for caution This is a retrospective study, including transfers of embryos of different stage (day 2 – day 5). However, the control group was matched to the study group, in terms of embryo stage. The number of previous treatments per couple was not included in the study. Wider implications of the findings Although double-vitrified embryos can lead to successful pregnancies, our results showed an adverse effect of double vitrification on embryo reproductive potential. To avoid lower pregnancy rates, culture of embryos until day 5 and cryopreservation of one embryo per vitrification device should be considered. Trial registration number not applicabe

Study question Are there differentially expressed genes (DEGs), in the testicular tissue of azoospermic males which could uncover tissue specific gene expression signatures, associated with idiopathic azoospermia? Summary answer The current findings link for the first time the pathophysiology of idiopathic azoospermia to the immune system and open a new era for further investigation What is known already Azoospermia is the most severe form of male infertility and affects 10% of the infertile men and 1% of the general male population which equals to several million men all over the world. A causal genetic factor is established in only 25% of the cases while in the remaining 75% there is no diagnosis and is termed idiopathic. Published data demonstrate that in idiopathic azoospermia heterogeneous genetic factors are the underlying cause. Clarifying the genetic basis of azoospermia will immensely improve our current clinical and treatment approaches for patient care at the levels of diagnosis, therapy, treatment, and safety Study design, size, duration During June 2020 and June 2021 testicular samples from 26 consented IVF patients were included in this study. The samples were divided in 7 pools based on the presence of testicular spermatozoa found. In particular, Pools 1-3 included testicular samples with high, average and very low presence of spermatozoa, Pools 4 & 5 samples with no spermatozoa found, and Pools 6-7 included only CF carriers. Pools 6 &7 were used as controls. Participants/materials, setting, methods Total RNA was isolated using the RΝeasy plus universal mini kit (Qiagen) and quantified using a photometer. Next, RNA sequencing was performed by Novogene, using the Illumina NovaSeq platform and the DEGs that were identified were processed using Gene Ontology (GO) functional enrichment analysis, pathway enrichment analysis and protein-protein interaction (PPI) network reconstruction using the Gene Ontology Resource, the KEGG database and the STRING database respectively. Main results and the role of chance In total RNA from up to 39.664 genes was detected and significant differences in gene expression (DEGs, log2fold change≥2, p-value < 0.05) were identified in the 7 pools analyzed. The top 10% of the protein coding DEGs from each comparison was further analyzed. Up to 1.900 protein coding genes were found to be common in at least two comparisons and exhibit consistent expression profiles. In particular, 920 genes were overexpressed in the “good quality” testicular samples (high & average presence of spermatozoa) while 940 genes were overexpressed in the “low quality” testicular samples (rare or no spermatozoa found). GO analysis revealed that the sexual reproduction, male gamete generation spermatogenesis, cilium movement and fertilization biological processes were enriched in the “good quality” testicular pools while the biological processes response to stimulus, response to stress, response to cytokine and defense response were overrepresented in the “low quality” testicular samples. The PPI network of the DEGs was reconstructed and hub proteins with a putative key role in the pathogenesis of azoospermia were identified. Limitations, reasons for caution While transcriptomics analysis is becoming a powerful analysis tool there are still technical limitations which may impact the accurate representation of the DEGs profiles found. The data obtained in this study represent the whole testicular tissue samples analyzed and they are not cell-type specific Wider implications of the findings The findings of this study demonstrate that in the “low quality” testicular samples, there is a significant under-expression of testis-specific genes directly involved in spermatogenesis and fertilization processes, an over-expression of the genes involved in the body’s immune defense system and advance our understanding in the pathophysiology of idiopathic azoospermia. Trial registration number Τ1EDK-02787

Study question Does artificial collapse of human blastocysts before vitrification affect the post warming quality of embryos and/or the reproductive outcome? Summary answer This study suggests that artificial collapse with laser pulse before vitrification significantly benefits blastocyst quality post-warming without improving reproductive outcome. What is known already The efficiency of vitrification of blastocysts can be influenced by various factors, such as the stage of the expansion and the quality of the embryos. Expanded blastocysts seem to be more sensitive and prone to cryo-injury during vitrification because of the large amount of blastocoelic fluid which may cause insufficient dehydration. Artificial collapse (AC) with micro-needles or with laser pulse can improve the vitrification procedure and protect the expanded blastocysts from cryoinjuries by reducing the fluid of the blastocoel. Study design, size, duration This prospective randomized study was performed at Embryolab Fertility Clinic, in Thessaloniki, Greece between July 2020 and November 2020 and included 94 ICSI treatments with no fresh embryo transfer. Patients with more than 4 blastocysts were randomized and allocated to the study (AC) group or control group. Randomization list was created by a computer-based program. The embryos were vitrified at the blastocyst stage and the best 1–2 embryos were transferred in a subsequent cycle. Participants/materials, setting, methods Patients were divided in two groups: AC group (n = 46) where 1 or 2 best expanded blastocysts were artificially collapsed by a laser pulse before vitrification and control group (n = 48) where the corresponding best expanded embryos remained untreated before vitrification. The embryos were graded according to Gardner’s criteria and vitrified using open system. Quality of embryos, pregnancy rate and clinical pregnancy rate from the first warming cycle were the parameters that were analyzed using z-test. Main results and the role of chance The analyzed embryos were in total 171, 85 in the AC group and 86 in the control group. The day 5 embryos in each group were 6.89 (±3.41) and 6.50 (±3.38) and the number of embryos per embryo transfer was 1.85 (±0.36) and 1.79 (±0.41) respectively. Cryoinjury was determined as the presence of degenerated cell in ICM or TE. In the AC group cryo-injury was significantly lower than in the control group [31.11% with at least 1 embryo per embryo transfer and 52.08% respectively (p = 0.0356), 6.67% with cryo-injury in both embryos and 14.58% respectively (p Limitations, reasons for caution The number of cases included in this study was limited and the live birth rate was not yet available. More prospective randomized studies are needed in order to validate the benefit of artificial collapse before the vitrification procedure. Wider implications of the findings: Laser artificial Collapse does not compromise expanded blastocyst quality, on the contrary it seems to reduce the amount of cryoinjury observed post warming. Whether it can improve the reproductive outcome, remains to be examined in larger scale studies. Trial registration number Not applicable

Study question What are the major problems faced by embryologists at 1) Clinic level, 2) Professional level, 3) Personal level, and 4) What are their career goals? Summary answer Embryologists, essential professionals of Fertility Centres, are less satisfied in many quantifiable aspects, but they love their profession and have many aspirational goals. What is known already IVF success depends in part on embryologists’ skills. The need to recognize clinical embryology as a specialty and clinical embryologists’ educational level, responsibilities, and workload have been addressed by a few national societies. However, data are lacking from the embryologists’ viewpoint at a global level about their profession. Qualitative data-analysis methods provide thick, rich descriptions of subjects’ thoughts, feelings, and lived experiences but can be time-consuming, labor-intensive, and prone to bias. Study design, size, duration A questionnaire was prepared using SurveyMonkey online software (SurveyMonkey, Inc., USA) and distributed to IVF lab professionals through embryology societies, online social media, and email databases. The questionnaire consisted of open-ended questions focused on identifying problems faced by embryologists at the clinic, in the profession, and in a personal level, as well as questions about their career outlook. The survey was active from May 2016 until February 2017. From 73 countries, 720 responses were obtained. Participants/materials, setting, methods Using natural language processing (NLP), the top 15 most frequently used keywords were identified and correlated with each other. Stronger correlation (≥0.5) between semantically similar words expressing a strong signal from each answer, and their usage was further analyzed for positive versus negative sentiment. By normalizing the frequency of positive/negative samples for each keyword as a percentage, “sentiment wheels” were produced, identifying the key concepts that respondents answered and quantifying how they felt about them. Main results and the role of chance The responses received were from 80% private, 17% public and 3% other ART settings distributed all over the world. From the embryologists’ viewpoints reported and after the NLP processing it was shown that the common topics related to strong negative sentiments were: embryologists’ remuneration (0.6) at the Clinic level; certification (0.7), recognition (0.5), respect (0.5), learn (0.5) and experience (0.5) at the Professional level; and remuneration (0.7), emotional (0.5) dealing (0.5) at the Personal level. Renumeration was reported and strongly related to embryologists’ viewpoint at both the clinic and personal level in combination with the need for certification, recognition and ongoing development at the Professional level. Moreover, the NLP processing demonstrated that the common topics on career goal analysis related to strong positive sentiments were: teaching (0.7), education (0.7), and continuation (0.5) all three topics are compatible with a professional orientation open to ongoing development and practice advancement. The NLP and the manual data analysis project an image of the typical embryologist as a knowledge seeking professional who is deeply dedicated to the job but feels the need for professional development and suffers some lack of recognition and feels in some cases not fairly treated as an employee. Limitations, reasons for caution The data obtained is limited. Only one natural language processing model was used to analyze the results. Different analysts using other methods may have different results. For these reasons, the results should be interpreted with caution. Wider implications of the findings: It is important to focus on the lab as an organization and not just a service for the patients in treatment at the moment. The NLP results ultimately obtained may help streamline professional satisfaction efforts, and guide future quality management strategies Trial registration number Not applicable

Genome-wide association studies have paved the way for the discovery of new markers regarding many diseases, including male infertility. A previous study on Caucasians highlighted 172 polymorphisms for their putative association with male infertility and we attempted to replicate these findings on our dataset comprising of Greek male individuals (n = 360). We retrieved 59 out of 172 polymorphisms and tested for all association models on 278 normospermic men and 82 patients with an abnormal seminogram, later separated into oligozoospermic and asthenozoospermic groups. Our findings indicate that two SNPs (rs2296225 in KIF17, rs7224496 in SMYD4) are associated with male infertility in the Greek population and have not been recorded in literature as of yet. These novel markers need further validation via additional studies and an increased individual number. All in all, replication studies, possess the power to validate existing polymorphisms found across all population and thus increase both statistical significance as well as identify novel potentially diagnostic markers.

Our ability to predict the potential of testicular spermatozoa to support embryonic development is still limited. Although motility of testicular spermatozoa is associated with embryo development, the impact of morphology and the presence of spermatozoa in the testicular sample has not been previously researched. Moreover, while the majority of data indicate no effect of cryopreservation, there are studies reporting impaired clinical outcomes due to testicular cryopreservation. In a retrospective study, 118 ICSI-TESE cycles were analysed to study the impact of (a) total quality of testicular tissue, (b) testicular tissue cryopreservation and (c) presence/motility/morphology of testicular spermatozoa in fertilisation rate, embryonic development, clinical pregnancy (CPR), ongoing pregnancy (OPR) and live birth rate (LBR). Results showed that fertilisation rate was significantly affected by both total quality of testicular tissue (p

The first isolation of human embryonic stem cells (hESC) reported in the late 90s opened a new window to promising possibilities in the fields of human developmental biology and regenerative medicine. Subsequently, the differentiation of hESC lines into different precursor cells showed their potential in treating different incurable diseases. However, this promising field has consistently had remarkable ethical and experimental limitations. This paper is a review of clinical trial studies dealing with hESC and their advantages, limitations, and other specific concerns. Some of the hESC limitations have been solved, and several clinical trial studies are ongoing so that recent clinical trials have strived to improve the clinical applications of hESC, especially in macular degeneration and neurodegenerative diseases. However, regarding hESC-based therapy, several important issues need more research and discussion. Despite considerable studies to Date, hESC-based therapy is not available for conventional clinical applications, and more studies and data are needed to overcome current clinical and ethical limitations. When all the limitations of Embryonic stem cells (ESC) are wholly resolved, perhaps hESC can become superior to the existing stem cell sources. This overview will be beneficial for understanding the standard and promising applications of cell and tissue-based therapeutic approaches and for developing novel therapeutic applications of hESC.

BACKGROUND: Male infertility is currently one of the most common problems faced by couples worldwide. We performed a GWAS on Greek population and gathered statistically significant SNPs in order to investigate whether they lie within or near lncRNA regions. OBJECTIVES: The aim of this study was to investigate whether polymorphisms on or near lncRNAs affect interactions with miRNAs and can cause male infertility. MATERIALS AND METHODS: In the present study, a GWAS was conducted, using samples from 159 individuals (83 normozoospermic individuals and 76 patients of known fertility issues). Standard procedures for quality controls and association testing were followed, based on case-control testing. RESULTS: We detected six lncRNAs (LINC02231, LINC00347, LINC02134, NCRNA00157, LINC02493, Lnc-CASK-1) that are associated with male infertility through their interaction with miRNAs. Furthermore, we identified the genes targeted by those miRNAs and highlighted their functions in spermatogenesis and the fertilization process. DISCUSSION AND CONCLUSION: lncRNAs are involved in spermatogenesis through their interaction with miRNAs. Thus, their study is very important, and it may contribute to the understanding of the molecular mechanisms underlying male infertility. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-020-01937-w) contains supplementary material, which is available to authorized users.

The first isolation of human embryonic stem cells (hESC) reported in the late 90s opened a new window to promising possibilities in the fields of human developmental biology and regenerative medicine. Subsequently, the differentiation of hESC lines into different precursor cells showed their potential in treating different incurable diseases. However, this promising field has consistently had remarkable ethical and experimental limitations. This paper is a review of clinical trial studies dealing with hESC and their advantages, limitations, and other specific concerns. Some of the hESC limitations have been solved, and several clinical trial studies are ongoing so that recent clinical trials have strived to improve the clinical applications of hESC, especially in macular degeneration and neurodegenerative diseases. However, regarding hESC-based therapy, several important issues need more research and discussion. Despite considerable studies to Date, hESC-based therapy is not available for conventional clinical applications, and more studies and data are needed to overcome current clinical and ethical limitations. When all the limitations of Embryonic stem cells (ESC) are wholly resolved, perhaps hESC can become superior to the existing stem cell sources. This overview will be beneficial for understanding the standard and promising applications of cell and tissue-based therapeutic approaches and for developing novel therapeutic applications of hESC.

Males with abnormal karyotypes and subgroups of fertile and infertile males with normal karyotypes may be at risk of producing unbalanced or aneuploid spermatozoa. Biological, clinical, environmental and other factors may also cause additional sperm aneuploidy. However, increased risk of sperm aneuploidy is directly related to chromosomally abnormal embryo production and hence to poor reproductive potential. This systemic literature review focuses on the identification of these males because this is an essential step in the context of assisted reproduction. This research may allow for a more personalised and, hence, more accurate estimation of the risk involved in each case, which in turn will aid genetic counselling for affected couples and help with informed decision-making.