The Role of One-Carbon Metabolism and Methyl Donors in Medically Assisted Reproduction: A Narrative Review of the Literature.

One-carbon (1-C) metabolic deficiency impairs homeostasis, driving disease development, including infertility. It is of importance to summarize the current evidence regarding the clinical utility of 1-C metabolism-related biomolecules and methyl donors, namely, folate, betaine, choline, vitamin B12, homocysteine (Hcy), and zinc, as potential biomarkers, dietary supplements, and culture media supplements in the context of medically assisted reproduction (MAR). A narrative review of the literature was conducted in the PubMed/Medline database. Diet, ageing, and the endocrine milieu of individuals affect both 1-C metabolism and fertility status. In vitro fertilization (IVF) techniques, and culture conditions in particular, have a direct impact on 1-C metabolic activity in gametes and embryos. Critical analysis indicated that zinc supplementation in cryopreservation media may be a promising approach to reducing oxidative damage, while female serum homocysteine levels may be employed as a possible biomarker for predicting IVF outcomes. Nonetheless, the level of evidence is low, and future studies are needed to verify these data. One-carbon metabolism-related processes, including redox defense and epigenetic regulation, may be compromised in IVF-derived embryos. The study of 1-C metabolism may lead the way towards improving MAR efficiency and safety and ensuring the lifelong health of MAR infants.

Sperm plasma membrane ion transporters and male fertility potential: A perspective under the prism of cryopreservation.

Intracellular calcium homeostasis plays a crucial role in spermatozoa by regulating physiological functions associated with sperm quality and male fertility potential. Intracellular calcium fine balance in the sperm cytoplasm is strictly dependent on sperm surface channels including the CatSper channel. CatSpers' role is to ensure the influx of extracellular calcium, while intracellular pH alkalinization serves as a stimulus for the activation of several channels, including CatSper. Overall, the generation of intracellular calcium spikes through CatSper is essential for fertilization-related processes, such as sperm hyperactivation, acrosome reaction, egg chemotaxis, and zona pellucida penetration. Multiple lines of evidence suggest that disruption in the close interaction among ions, pH, and CatSper could impair male fertility potential. In contemporary times, the growing reliance on Medically Assisted Reproduction procedures underscores the impact of cryopreservation on gametes. In fact, a large body of literature raises concerns about the cryo-damages provoked by the freeze-thawing processes, that can affect the plasma membrane integrity, thus the structure of pivotal ion channels, and the fine regulation of both intracellular calcium and pH. This review aims to provide an overview of the importance of the CatSper channel in sperm quality and further fertilization potential. Additionally, it addresses the emerging issue of cryopreservation's impact on the functionality of this sperm channel.

Evaluation of Sperm DNA Fragmentation Using Two Different Methods: TUNEL via Fluorescence Microscopy, and Flow Cytometry.

Background and Objectives: Sperm DNA fragmentation refers to any break in one or both of the strands of DNA in the head of a sperm. The most widely used methodologies for assessing sperm DNA fragmentation are the sperm chromatin structure assay (SCSA), the sperm chromatin dispersion assay (SCD), the single-cell gel electrophoresis assay (SCGE-comet), and the terminal-deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end labelling (TUNEL) assay. The aim of this study was to compare the efficiency and sensitivity of the analysis of sperm DNA fragmentation using TUNEL via fluorescence microscopy, and flow cytometry. Materials and Methods: Semen samples were collected and analyzed for standard characteristics using light microscopy, and for sperm DNA fragmentation using both TUNEL via fluorescence microscopy, and flow cytometry. Results: There were no significant differences in the values of the sperm DNA fragmentation index (DFI) obtained when the analysis was performed using TUNEL or flow cytometry (p = 0.543). Spearman's correlation analysis revealed a significant negative correlation between sperm motility (%) and sperm DNA fragmentation (p < 0.01), as well as between sperm concentration and sperm DNA fragmentation (p < 0.05). The Mann-Whitney U test showed no significant difference in the DFI among couples with repeated implantation failure (RIF) and miscarriages (p = 0.352). Conclusions: Both methods (TUNEL via fluorescence microscopy, and flow cytometry) have a high efficiency and sensitivity in accurately detecting sperm DNA fragmentation, and can be effectively used to assess male fertility.

A comprehensive review and update on human fertility cryopreservation methods and tools.

The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.

The impact of cryopreservation on both sperm HPV-negative and positive subtypes.

It is well known that various human papillomavirus (HPV) genotypes are present in semen specimens. Also, it has been demonstrated that sperm parameters are negatively affected when HPV infection is present in the sperm sample. Besides all these, the effect of cryopreservation on HPV sensitivity and resistance is not known. The aim of the present study is to evaluate first the prevalence of HPV and secondly to elucidate whether cryopreservation of sperm HPV-positive samples has any effect on the viability of HPV. For this purpose, a cohort of 78 sperm specimens was used from a respective number of patients. After giving informed consent, semen analysis was performed. Each sperm sample was divided into four equal aliquots. The first one (fresh) was evaluated for the prevalence of HPV, while the other three aliquots were cryopreserved by adding an equal quantity of cryoprotectant and plunged into the LN. Each of the three aliquots was thawed 3, 6, and 12 months later, respectively, so as to evaluate whether there is a time-resistance period of HPV prevalence. HPV infection was found to be in eleven sperm samples, demonstrating a 14.1% (11/78) HPV prevalence. Among the HPV-positive samples, six of them were high-risk and the remaining were low-risk genotypes. Moreover, the high-risk fresh samples demonstrated higher motility values than the low-risk samples (60% ± 2.7 vs 45.6% ± 3.7, p < .05), while semen volume in the high-risk samples was significantly lower than the respective volume in the low-risk samples (2.26 ± 0.2ml vs 3.5 ± 0.6ml, p < .05). Interestingly, cryopreservation of the HPV-positive samples resulted in the sustainability and time-resistance of HPV in all high-risk HPV-positive samples, something that was not the case with the low-risk HPV-positive samples. Conclusively, sperm samples infected with high-risk HPV, demonstrate lower sperm parameters and time-resistance activity during cryopreservation.

Clinical Outcome, Socioeconomic Status and Psychological Constrains of Patients Undergoing Preimplantation Genetic Testing (PGT) in Northern Greece.

Background and objectives: Preimplantation genetic testing (PGT) offers patients the possibility of having a healthy baby free of chromosomal or genetic disorders. The present study focuses on the application of PGT for patients located in Northern Greece, investigating their clinical outcomes, their motives, and their overall physical and emotional experience during the treatment, in association with their socioeconomic background. Materials and Methods: Couples who underwent PGT for a monogenic condition (PGT-M, n = 19 cycles) or aneuploidy (PGT-A, n = 22 cycles) participated in the study. Fertilization, implantation, and pregnancy rates were recorded for all cycles. The couples were asked to fill in a questionnaire about the consultation they had received prior to treatment, their sociodemographic information, and the psychological impact PGT had on both the female and male partner. Results: The fertilization, implantation, and ongoing pregnancy rates for the PGT-M and PGT-A cycles were 81.3%, 70.6%, and 52.9%, and 78.2%, 64.3%, and 57.1%, respectively. Females experienced more intense physical pain than their male partners while psychological pain was encountered by both partners and occasionally in higher instances in males. No typical socioeconomic background of the patients referred for PGT in Northern Greece was noticed. Conclusion: PGT is an attractive alternative to prenatal diagnosis (PND), aiming to establisha healthy pregnancy by identifying and avoiding the transfer of chromosomally or genetically abnormal embryos to the uterus. Although the benefits of PGT were well-received by all patients undergoing the procedure, psychological pain was evident and especially prominent in patients with a previous affected child or no normal embryos for transfer. Holistic counseling is of utmost importance in order to make patients' experience during their journey to have a healthy baby less emotionally demanding and help them make the right choices for the future.

Bioethics in human embryology: the double-edged sword of embryo research.

There has been a significant increase in the use of assisted reproductive therapies (ARTs) over the past several decades, allowing many couples with infertility to conceive. Despite the achievements in this field, a mounting body of evidence concerning the epigenetic risks associated with ART interventions such as ovarian hormonal stimulation, intracytoplasmic sperm injection (ICSI), and in vitro culture (IVC) of oocytes and embryos has also emerged. Induced development of multiple follicles, the IVC media itself, and extended culture may alter the epigenome of both gametes and embryos, resulting in yet to be fully understood developmental, postnatal, and adult life health consequences. Investigators have attempted to decipher the molecular mechanisms mediating ART-induced epigenetic changes using either human samples or animal models with some success. As research in this field continues to expand, the ethical responsibilities of embryologists and researchers have become critically important. Here, we briefly discuss the ethical aspects of ART research, concentrating on the constraints arising from the perceived 'unnaturalness' of many of these procedures. Secondly, we focus on the bioethics and morality of human embryo research in general and how ethically acceptable model systems may be used to mimic early human embryogenesis. Lastly, we review the 14-day culture limit of human embryos and the notion that this rule could be considered of taken into account using new technologies and cues from animal models. The 'black box' of early post-implantation embryogenesis might be revealed using embryo models. As long as this distinct moral line has been drawn and closely followed, we should not fear scientific growth in embryo research. Although in vitro fertilization (IVF) is ethically acceptable, research with human embryos to improve its success raises serious ethical concerns that are in need of constant revisiting.Glossary index: Moral status: the ascription of obligations and rights to embryos on the basis of sentience; Sentience: the capacity of the developing embryo to experience feelings and sensations, such as the awareness of pain; Ectogenesis: the growth of the embryo in an artificial environment outside the mother's body.

Effects of Different Drug Therapies and COVID-19 mRNA Vaccination on Semen Quality in a Man with Ankylosing Spondylitis: A Case Report.

Background and Objectives: Ankylosing spondylitis (AS) is a condition that affects 0.1% to 0.5% of the adult population. The aim of this case report was to investigate the possible effects of the drugs taken for treatment of AS as well as mRNA vaccination for COVID-19 on semen quality by performing a highly detailed analysis. Materials and Methods: Sperm characteristics were examined by light microscopy, DNA fragmentation (DFI) was analysed by flow cytometry and morphology was evaluated by transmission electron microscopy (TEM). Results: Semen analysis under therapy with (1) celecoxib and sulphasalazine showed: concentration 47 million/mL, 53% progressive motility, 7% normal morphology and 9.6% DFI, (2) Golimumab and before mRNA Vaccination showed: concentration 108 million/mL, 82% progressive motility, 1% normal morphology and 7.6% DFI, and (3) Golimumab and after 3 doses of mRNA Vaccination showed: concentration 142 million/mL, 85% progressive motility, 1% normal morphology and 6.8% DFI. TEM revealed head, neck and tail abnormalities, as well as the presence of cells with incomplete spermiogenesis white cells and phagocytes in the sample under therapy with celecoxib and sulphasalazine. Golimumab treatment lead to an increased incidence of elongated heads but in general reduced inflammation as no white cells were evident in TEM. Conclusion: The anti-inflamatory drugs celecoxib and sulphasalazine had no adverse effect on sperm quality as all parameters were within normal limits and the patient achieved under that treatment 2 pregnancies following natural conception that lead to the birth of a healthy boy and girl respectively. Anti-TNFa treatment with Golimumab exerted a negative effect on morphology but not on concentration, motility and DFI. After 3 doses of mRNA Vaccination, sperm concentration increased while motility, morphology and DFI remained similar to the values before vaccination suggesting no negative effect of the mRNA vaccine for COVID-19 on sperm quality.

Insights into the Role of Telomeres in Human Embryological Parameters. Opinions Regarding IVF.

Telomeres promote genome integrity by protecting chromosome ends from the activation of the DNA damage response and protecting chromosomes from the loss of coding sequences due to the end replication problem. Telomere length (TL) is progressively shortened as age progresses, thus resulting in cellular senescence. Therefore, TL is in strong adverse linear correlation with aging. Mounting evidence supports the notion that telomeres and male/female infertility are in a close relationship, posing the biology of telomeres as a hot topic in the era of human-assisted reproduction. Specifically, the length of sperm telomeres is gradually increasing as men get older, while the telomere length of the oocytes seems not to follow similar patterns with that of sperm. Nonetheless, the telomere length of the embryos during the cleavage stages seems to have a paternal origin, but the telomere length can be further extended by telomerase activity during the blastocyst stage. The latter has been proposed as a new molecular biomarker with strong predictive value regarding male infertility. As far as the role of telomeres in assisted reproduction, the data is limited but the length of telomeres in both gametes seems to be affected mainly by the cause of infertility rather than the assisted reproductive therapy (ART) procedure itself. The present review aims to shed more light into the role of telomeres in human embryological parameters, including gametes and embryos and also presents opinions regarding the association between telomeres and in vitro fertilization (IVF).

The Current Evidence Regarding COVID-19 and Pregnancy: Where Are We Now and Where Should We Head to Next?

Despite the volume of publications dedicated to unraveling the biological characteristics and clinical manifestations of SARS-CoV-2, available data on pregnant patients are limited. In the current review of literature, we present an overview on the developmental course, complications, and adverse effects of COVID-19 on pregnancy. A comprehensive review of the literature was performed in PubMed/Medline, Embase, and Cochrane Central databases up to June 2021. This article collectively presents what has been so far reported on the identified critical aspects, namely complications during pregnancy, delivery challenges, neonatal health care, potential routes of viral transmission, including vertical transmission or breastfeeding, along with the risks involved in the vaccination strategy during pregnancy. Despite the fact that we are still largely navigating uncharted territory, the observed publication explosion in the field is unprecedented. The overwhelming need for data is undoubtable, and this serves as the driver for the plethora of publications witnessed. Nonetheless, the quality of data sourced is variable. In the midst of the frenzy for reporting on SARS-CoV-2 data, monitoring this informational overload is where we should head to next, considering that poor quality research may in fact hamper our attempts to prevail against this unparalleled pandemic outbreak.

The Impact of SARS-CoV-2 on Sperm Cryostorage, Theoretical or Real Risk?

Cryopreservation of human gametes and embryos as well as human reproductive tissues has been characterized as an essential process and aspect of assisted reproductive technology (ART). Notably, sperm cryopreservation is a fundamental aspect of cryopreservation in oncological patients or patients undergoing gonadotoxic treatment. Given that there is a risk of contamination or cross-contamination, either theoretical or real, during the procedures of cryopreservation and cryostorage, both the European Society for Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM) have provided updated guidelines for preventing or reducing the contamination risk of sexually transmitted viruses. Given the ongoing and worldwide COVID-19 pandemic, there is considerable interest in what measures should be taken to mitigate SARS-CoV-2 contamination during cryopreservation and cryostorage of semen samples. The SARS-CoV-2 virus is the virus that causes COVID-19, and whose transmission and infection is mainly aerosol-mediated. Several ART professional societies, including ESHRE and ASRM have proposed measures to mitigate the spread of the SARS-CoV-2 virus. Whether the proposed safety directives are enough to mitigate the possible SARS-CoV-2-contamination of sperm samples during cryopreservation or whether the policies should be re-evaluated will be discussed in this review. Additionally, insights regarding the possible impact of COVID-19 vaccination on the safety of sperm cryopreservation will be discussed.

Effect of adiponectin on estradiol and progesterone secretion from human luteinized granulosa cells in vitro.

Ιnformation on the role of adiponectin in human ovarian steroidogenesis is limited. The present study aimed to investigate the effect of different doses of adiponectin on the secretion of estradiol and progesterone by human luteinized granulosa cells in culture. Granulosa cells, obtained from women undergoing in vitro fertilization (IVF) treatment, were pre-incubated for 24 h and then cultured for 48 h. Adiponectin was used in 3 doses, i.e., 5, 10, and 100 µg/ml alone and in combinations with FSH (10 and 100 ng/ml). Estradiol and progesterone were measured by radioimmunoassays in culture supernatants at 24 h and 48 h. Adiponectin after 48 h of culture stimulated the secretion of estradiol and, to a lesser extent, progesterone in a dose-dependent manner. FSH showed a variable effect on steroidogenesis. However, when the low dose FSH was combined with adiponectin, estradiol, and progesterone secretion were increased disproportionally to the dose of adiponectin. With the high dose FSH, the positive effect of adiponectin on FSH-induced estradiol secretion was less pronounced, while the effect on progesterone secretion was negligible. This study shows for the first time a stimulatory effect of adiponectin on the secretion of estradiol and progesterone by human luteinized granulosa cells in vitro. It is suggested that adiponectin plays a paracrine role in human ovarian steroidogenesis by sensitizing the granulosa cells to FSH.

SARS-CoV-2 vs. human gametes, embryos and cryopreservation.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, is an unprecedented global situation, and all countries have adopted their own measurements to mitigate the spread of the virus in the first as well as in the subsequent waves of infection. All measures, especially in the first wave of the pandemic, were in combination with recommendations provided by professional and scientific organizations. Similar measures were applied to specific procedures, such as the management of infertility, including in vitro fertilization-embryo transfer (IVF-ET) treatments. Although there is no clear scientific evidence yet that the SARS-CoV-2 may exert negative effects on IVF outcome, especially at the early stages, several clinical reports indicate that the virus may impact male fertility through specific receptors presented at the somatic cells of the testis and used by the virus in order to gain entry to the respective cells. Nevertheless, it is not unreasonable to suspect that the virus may affect sperm function as well as oocyte performance directly through specific receptors or indirectly through other signaling pathways. Despite the good practice of IVF laboratory techniques, culture media may also be contaminated during equilibration when airborne virus's particles can contaminate culture media from an already infected embryology area or staff. Furthermore, although there is no clinical evidence, liquid nitrogen could be a route of infection for gametes and embryos when it has been contaminated during production or transportation. Therefore, cryopreservation of gametes and embryos must be virus-free. This communication aims to provide some aspects of the possible impact of the virus on gametes and embryos and how it may affect the cryopreservation procedures.Abbreviations: ACE2: angiotensin- converting enzyme 2; ART: assisted reproductive technology; ASRM: American Society for Reproductive Medicine; CDC: Centers for Disease Control and Prevention; COVID-19: coronavirus disease 2019; ESHRE: European Society of Human Reproduction and Embryology; ET: embryo transfer; FSH: follicle stimulating hormone; IFFS: International Federation of Fertility Societies; IVF: in vitro fertilization; LH: luteinizing hormone; LN: liquid nitrogen; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; T: testosterone; WHO: World Health Organization.

COVID-19 and human reproduction: A pandemic that packs a serious punch.

The COVID-19 pandemic has led to a worldwide health emergency that has impacted 188 countries at last count. The rapid community transmission and relatively high mortality rates with COVID-19 in modern times are relatively unique features of this flu pandemic and have resulted in an unparalleled global health crisis. SARS-CoV-2, being a respiratory virus, mainly affects the lungs, but is capable of infecting other vital organs, such as brain, heart and kidney. Emerging evidence suggests that the virus also targets male and female reproductive organs that express its main receptor ACE2, although it is as yet unclear if this has any implications for human fertility. Furthermore, professional bodies have recommended discontinuing fertility services during the pandemic such that reproductive services have also been affected. Although increased safety measures have helped to mitigate the propagation of COVID-19 in a number of countries, it seems that there is no predictable timeline to containment of the virus, a goal likely to remain elusive until an effective vaccine becomes available  and widely distributed across the globe. In parallel, research on reproduction has been postponed for obvious reasons, while diagnostic tests that detect the virus or antibodies against it are of vital importance to support public health policies, such as social distancing and our obligation to wear masks in public spaces. This review aims to provide an overview of critical research and ethics issues that have been continuously emerging in the field of reproductive medicine as the COVID-19 pandemic tragically unfolds.Abbreviations: ACE2: angiotensin- converting enzyme 2; ART: Assisted reproductive technology; ASRM: American Society for Reproductive Medicine; CCR9: C-C Motif Chemokine Receptor 9; CDC: Centers for Disease Control and Prevention; COVID-19: Coronavirus disease 2019; Ct: Cycle threshold; CXCR6: C-X-C Motif Chemokine Receptor 6; ELISA: enzyme-linked immunosorbent assay; ESHRE: European Society of Human Reproduction and Embryology; ET: Embryo transfer; FSH: Follicle Stimulating Hormone; FFPE: formalin fixed paraffin embedded; FYCO1: FYVE And Coiled-Coil Domain Autophagy Adaptor 1; IFFS: International Federation of Fertility Societies; IUI: Intrauterine insemination; IVF: In vitro fertilization; LH: Luteinizing Hormone; LZTFL1: Leucine Zipper Transcription Factor Like 1; MAR: medically assisted reproduction services; MERS: Middle East Respiratory syndrome; NGS: Next Generation Sequencing; ORF: Open Reading Frame; PPE: personal protective equipment; RE: RNA Element; REDa: RNA Element Discovery algorithm; RT-PCR: Reverse=trascriptase transcriptase-polymerase chain reaction; SARS: Severe acute respiratory syndrome; SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2; SLC6A20: Solute Carrier Family 6 Member 20; SMS: Single Molecule Sequencing; T: Testosterone; TMPRSS2: transmembrane serine protease 2; WHO: World Health Organization; XCR1: X-C Motif Chemokine Receptor.

Exogenous progesterone for LH surge prevention is redundant in ovarian stimulation protocols.

During ovarian stimulation for IVF-embryo transfer treatment, a premature LH surge may lead to progesterone elevation that disrupts endometrial maturation and affects the probability of pregnancy following fresh embryo transfer. Preventing this LH surge and progesterone elevation using gonadotrophin-releasing hormone (GnRH) analogues is considered a standard practice. The same policy applies to cycles in which the 'freeze-all' protocol has been selected from the outset (e.g. donors), but the need for this has not been discussed. Moreover, in 'freeze-all' cycles, exogenous progesterone administration tends to replace GnRH antagonists, without reducing efficacy after embryo transfer in frozen-thawed cycles. Nevertheless, as exogenous progesterone is expected to have the same impact on the endometrium as endogenous progesterone, it is clear that, unlike in fresh cycles, in 'freeze-all' cycles an endogenous LH surge prevention does not seem necessary. Therefore, both GnRH antagonists and exogenous progesterone appear to be redundant in 'freeze-all' cycles, and in this context the indications for the use of GnRH analogues in ovarian stimulation protocols need to be revisited.

COVID-19 and fertility: a virtual reality.

The COVID-19 pandemic is an extraordinary global situation, and all countries have adopted their own strategies to diminish and eliminate the spread of the virus. All measures are in line with the recommendations provided by the World Health Organization. Scientific societies, such as the European Society for Human Reproduction and Embryology and American Society for Reproductive Medicine, have provided recommendations and guidance to overcome and flatten the growing curve of infection in patients who undergo IVF treatments. Although there is as yet no evidence that the virus causing COVID-19 might have negative effects on IVF outcomes, fertility treatments have been postponed in order to support healthcare systems by avoiding placing them under additional stress. The possibility of the virus affecting sperm function and egg performance cannot be excluded. In addition, an indirect effect of the virus on gametes and embryos during their manipulation cannot be ruled out. This commentary aims to provide some ideas on the possible effect of the virus on gametes and embryos, as well as how it could affect the normal functioning of the embryology laboratory.

Assessing Clinical Embryology Research: A Global Bibliometric Analysis.

Background and Objectives: The evaluative strength of available bibliometric tools in the field of clinical embryology has never been examined in the literature. The aim is to bring insight regarding the identity of clinical embryology research, introducing concerns when solely relying on the methodology of bibliometric analysis. Methods: An all-inclusive analysis of the most bibliometrically highlighted scientific contributions regarding the cornerstones of clinical embryology was performed employing the Scopus, Web of Science (WoS) and PubMed databases, between 1978-2018. An analysis of the number of publications, respective citations and h-index, g-index, along with m-quotient is presented. The top 30 contributing authors for each distinctive area of research are listed. An attempt at visualizing the yearly published articles, clusters, and collaborations of authors, along with the geographic origin of publications, is also presented. Results: Combining all searches and keywords yielded 54,522 results. In the Scopus database, employing the keyword "In Vitro Fertilization" yielded 41,292 results. The publications of the top five authors in each research field were analytically presented and compared to the total number of publications for each respective field. The research field of Preimplantation Genetic Diagnosis/Screening/Testing was allocated the highest percentage of publications produced by the top five authors. Regarding journal bibliometrics, based on the year 2017 metrics, there are only 29 journals according to WoS that refer to "Reproductive Biology", ranking it 187th among 235 disciplines. The USA produced the highest number of publications (12,537). Conclusion: Results indicate an explosion of interest published in the literature regarding the field of clinical embryology. Further analysis on collaborations and the trends involved should be of added value as productivity between countries varies significantly. This may guide researchers, in vitro fertilization professionals, and prospective authors during literature search, while proving useful regarding manuscript design and concurring on keywords and abstract content.

Investigating the Optimal Time for Intrauterine Human Chorionic Gonadotropin Infusion in Order to Improve IVF Outcome: A Systematic Review and Meta-Analysis.

BACKGROUND/AIM: Studies on the impact of intrauterine human Chorionic Gonadotropin (hCG) administration in order to improve the In Vitro Fertilization (IVF) outcome have yielded conflicting results. The aim of the present systematic review and meta-analysis is to investigate whether timing of intrauterine hCG administration prior to embryo transfer affects its efficiency. MATERIALS AND METHODS: A systematic search of the literature on Pubmed/Medline, Embase and Cochrane databases was performed. Only Randomized Control Trials were included in this meta-analysis. RESULTS: Live birth rates were not improved following hCG administration (RR=1.13, 95%CI=0.88-1.46, p=0.34) in the pooled results. Combined live birth and ongoing pregnancy rates were borderline statistically significant following hCG administration (RR=1.27, 95%CI=1.00-1.62, p=0.05). Following subgroup analysis regarding live birth and ongoing pregnancy rates, only the 5-12 minutes prior to the embryo transfer group reported a statistically significant improvement. CONCLUSION: Intrauterine infusion of hCG within an IVF-Intracytoplasmic Sperm Injection (ICSI) cycle improves outcome only when administered 5-12 min prior to embryo transfer.

What will the future hold for artificial organs in the service of assisted reproduction: prospects and considerations.

Assisted reproduction provides a wide spectrum of treatments and strategies addressing infertility. However, distinct groups of infertile patients with unexplained infertility, congenital disorders, and other complex cases pose a challenge in in vitro fertilization (IVF) practices. This special cohort of patients is associated with futile attempts, IVF overuse, and dead ends in management. Cutting edge research on animal models introduced this concept, along with the development of artificial organs with the aim to mimic the respective physiological functions in reproduction. Extrapolation on clinical application leads to the future use of infertility management in humans. To date, the successful clinical application of artificial reproductive organs in humans is not feasible because further animal model studies are required prior to clinical trials. The application of these artificial organs could provide a solution to infertility cases with no other options. This manuscript presents an overview on the current status, future prospects, and considerations on the potential clinical application of artificial ovary, uterus, and gametes in humans. This paper presents how the IVF practice landscape may be shaped and challenged in the future, along with the subsequent concerns in assisted reproductive treatments.