BACKGROUND: Assisted Reproductive Technology utilizes human sperm, eggs, or embryos in vitro to produce pregnancy. However, there is no evidence of the acceptance of these technologies by the community.
OBJECTIVE: This study aimed to determine the pooled prevalence of positive attitudes toward the acceptance of donor eggs, embryos, and sperm.
METHODS: The protocol was registered in PROSPERO (number: CRD42022348036). The Condition, Context and Population (CoCoPop) protocol of the systematic review was used to address the relevant questions regarding the objective of the study. Data were extracted into Excel and pooled estimates were calculated using STATA Version 16.
RESULTS: The pooled prevalence of positive attitudes toward accepting donor eggs, embryos, and sperms was 38.63%, 33.20%, and 31.34%, respectively. Subgroup analysis revealed that the pooled prevalence of positive attitudes toward accepting donor eggs was high in non-Asian countries (47.78%) and among infertile men (38.60%). Similarly, the pooled prevalence of positive attitudes toward accepting donor eggs was high in non-Asian countries (47.78%) and among infertile men (28.67%). However, the pooled prevalence of positive attitudes toward accepting donor sperm was high in non-Asian countries (37.6%) and among infertile women (28.19%).
CONCLUSIONS: The pooled estimate of the prevalence of positive attitudes toward accepting donor eggs was higher than the prevalence of positive attitudes toward accepting donor embryos and sperm. Infertile men and non-Asian countries have a higher prevalence of positive attitudes toward accepting eggs and embryos, whereas non-Asian countries and infertile women present a higher prevalence of positive attitudes toward accepting donor sperm. Therefore, regulatory bodies and policymakers should modify their rules and regulations to ensure the availability of minimum standards for the ethical and safe practice of donor conception as a treatment for infertility at national and international levels.
Assisted Reproductive Technology (ART) utilizes human sperm, eggs, or embryos in vitro to induce pregnancy; however, there is no evidence of community acceptance of these technologies. A systematic review and meta-analysis found that 38.63% of infertile couples had positive attitudes toward donor eggs, while 33.20% and 31.34% had negative attitudes. Females are more amenable to accepting donor gametes, embryos, or eggs than males, and females are more amenable to accepting donor eggs than donor sperm. To improve attitudes toward donor conception, infertile couples must understand the medical and obstetric risks associated with donor-assisted conception. This review recommends strengthening counseling for infertile couples and offering support to those with negative attitudes toward donor conception. Regulatory bodies and policymakers should consider the needs of infertile couples and modify their rules to ensure minimum standards for ethical and safe practices of donor conception as a treatment for infertility.

Recent advances in methods to culture pluripotent stem cells to model human development have resulted in entities that increasingly have recapitulated advanced stages of early embryo development. These entities, referred to by numerous terms such as embryoids, are becoming more sophisticated and could resemble human embryos ever more closely as research progresses. This paper reports a systematic review of the ethical, legal, regulatory, and policy questions and concerns found in the literature concerning human embryoid research published from 2016 to 2022. We identified 56 papers that use 53 distinct names or terms to refer to embryoids and four broad categories of ethical, legal, regulatory, or policy considerations in the literature: research justifications/benefits, ethical significance or moral status, permissible use, and regulatory and oversight challenges. Analyzing the full range of issues is a critical step toward fostering more robust ethical, legal, and social implications research in this emerging area and toward developing appropriate oversight.

Recurrent miscarriage is classically defined as three or more consecutive pregnancy losses in about 1-5% of couples trying to conceive. However, several researchers have amended this to two or more because of the recent increase in childless miscarriages. Recurrent miscarriage is a clinical challenge for clinicians because there are many possible causes, and diagnostic testing is expensive and time-consuming. Established causes of recurrent miscarriage are antiphospholipid antibodies, uterine anomalies, and abnormal chromosomes in either partner, particularly translocations. Uterine anatomical abnormalities, endocrine abnormalities, infections, immunologic factors, environmental factors, metabolic or hormonal disorders, sperm quality, and maternal and paternal age have each been linked. Among them, the genetic factor plays a significant role in recurrent miscarriage. Approximately 70% of miscarriage conceptions with sporadic spontaneous miscarriage reveal some chromosome abnormality. Specifically, recurrent miscarriage can be caused by a structural or numerical defect in the parents\' or fetus\' chromosomes. Recurrent miscarriage has been linked to several genes, including those involved in oxidative stress, angiogenesis, clotting, and inflammation. Despite several well-known etiologic factors, the etiology of recurrent miscarriage is unknown in over half of all instances. The current review aims to analyse the role of the genetic basis of recurrent miscarriages.

UNASSIGNED: Telomeres have an essential role in maintaining the integrity and stability of the human chromosomal genome and preserving essential DNA biological functions. Several articles have been published on the association of STL with male semen parameters and clinical pregnancy. The results, however, are either inconclusive or inconsistent. Therefore, this meta-analysis aimed to systematically assess the accuracy and clinical value of sperm telomere length (STL) as a new marker for diagnosing male infertility and predicting the quality of embryonic development.
UNASSIGNED: We performed a comprehensive systematic search for relevant publications in PubMed, the Cochrane Library, Web of Science, Embase, Scopus, and Ovid, from database build to August 2022. All experimental studies exploring the association of STL with male semen quality, male infertility, or embryonic development were included.
UNASSIGNED: Overall, Twelve prospective observational cohort studies (1700 patients) were eligible for inclusion in the meta-analysis. The meta-analysis showed a positive linear correlation between STL and semen parameters. The optimal cut-off value for STL diagnosing male infertility was 1.0, with a sensitivity and specificity of 80%. Regarding STL and embryonic development, the clinical pregnancy rate was associated with longer STL, and there was no significant difference between the two groups regarding fertilization rate.
UNASSIGNED: Our study showed that STL has good diagnostic and predictive value for male fertility and clinical pregnancy and could be used as a new biomarker for diagnosing male infertility and predicting embryonic development.
UNASSIGNED: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022303333.

Heavy metals pollution causes a threat to the aquatic environment and to its inhabitants when their concentrations exceed safe limits. Heavy metals cause toxicity in fish due to their non-biodegradable properties and their long persistence in the environment. This review investigated the effects of heavy metals on early development, growth and reproduction of fish. Fish embryos/larvae and each developmental stage of embryo respond differently to the intoxication and vary from species to species, types of metals and their mode of actions, concentration of heavy metals and their exposure time. Many of the heavy metals are considered as essential nutrient elements that positively improve the growth and feed utilization of fishes but upon crossing the maximum tolerable limit these metals cause not only a hazard to fish health but also to human consumers and the disruption of ecological systems. Reduced gonadosomatic index (GSI), fecundity, hatching rate, fertilization success, abnormal shape of reproductive organs, and finally failure of reproduction in fish have been attributed to heavy metal toxicity. In summary, this review sheds light on the manipulation of fish physiology by heavy metals and seeks to raise sensitivity to the prevention and control of aquatic environmental contamination, particularly from heavy metals.

Over the last decades, extracellular vesicles (EVs) have been found to be implicated in a complex universal mechanism of communication between different cell types. EVs are nanostructures of lipid nature that have an exosomal or ectosomal biogenesis, responsible for the intercellular transport of proteins, lipids, carbohydrates, nucleic acids, ions, among other molecules. The content of EVs can vary due to various factors such as hormonal stimuli, non-physiological conditions, metabolic state, etc. Once EVs reach their target cell, they can modulate processes such as gene expression, metabolism, response to external factors, and can even be associated with the delivery of molecules involved in epigenetic inheritance processes in germ cells. In mammalian reproduction, EVs have been shown to play an important role, either in vivo or in vitro, modulating a variety of processes in sperm, oocytes and embryos, and in their respective environments. Moreover, EVs represent a biodegradable, harmless and specific vehicle, which makes them attractive allies to consider when improving assisted reproductive technologies (ARTs). Therefore, the present review aims to describe the content of the main EVs involved in mammalian reproduction and how they can vary due to different factors, as well as to detail how EVs modulate, directly or indirectly, different molecular processes in gametes and embryos. In addition, we will highlight the mechanisms that remain to be elucidated. We will also propose new perspectives according to the characteristics of each particular EV to improve the different ARTs.

Review the safety of fertility preservation through ovarian stimulation with oocyte or embryo cryopreservation, including cycle and medication options.
A systematic review of peer-reviewed sources revealed 2 applicable randomized control trials and 60 cohort studies as well as 20 additional expert opinions or reviews.
The capacity for future family building is important for the majority of reproductive age people, despite life-altering medical or oncologic diagnosis. Modern fertility preservation generates a high rate of oocyte yield while utilizing protocols that can be started at multiple points in the menstrual cycle and suppressing supra-physiologic levels of estrogen. Finally, more than one quarter of fertility preservation patients will return to later utilize fertility services.
For most patients, fertility preservation can safely be pursued and completed within 2 weeks without affecting disease severity or long-term survival.

As the coronavirus pandemic is far from ending, more questions regarding the female reproductive system, particularly fertility issues, arise. The purpose of this paper is to bring light upon the possible link between COVID-19 and women\'s reproductive health. This review emphasizes the effect of SARS-CoV-2 on the hormones, endometrium and menstrual cycle, ovarian reserve, follicular fluid, oocytes, and embryos. The results showed that endometrial samples did not express SARS-CoV-2 RNA. Regarding the menstrual cycle, there is a large range of alterations, but they were all reversible within the following months. The ovarian reserve was not significantly affected in patients recovering from both mild and severe infection in most cases, except one, where the levels of AMH were significantly lower and basal follicle-stimulating hormone (FSH) levels were increased. All COVID-19 recovered patients had positive levels of SARS-CoV-2 IgG in the follicular fluid. The amount of retrieved and mature oocytes and the fertilization rate were unharmed in three studies, except for one study, where the quantity of retrieved and mature oocytes was reduced in patients with higher levels of SARS-CoV-2 antibodies. The numbers of blastocysts, top-quality embryos, and euploid embryos were affected in most of the studies reviewed.

BACKGROUND: Genetic testing of preimplantation embryos has been used for preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). Microarray technology is being introduced in both these contexts, and whole genome sequencing of blastomeres is also expeted to become possible soon. The amount of extra information such tests will yield may prove to be beneficial for embryo selection, will also raise various ethical issues. We present an overview of the developments and an agenda-setting exploration of the ethical issues.
METHODS: The paper is a joint endeavour by the presenters at an explorative \'campus meeting\' organized by the European Society of Human Reproduction and Embryology in cooperation with the department of Health, Ethics & Society of the Maastricht University (The Netherlands).
RESULTS: The increasing amount and detail of information that new screening techniques such as microarrays and whole genome sequencing offer does not automatically coincide with an increasing understanding of the prospects of an embryo. From a technical point of view, the future of comprehensive embryo testing may go together with developments in preconception carrier screening. From an ethical point of view, the increasing complexity and amount of information yielded by comprehensive testing techniques will lead to challenges to the principle of reproductive autonomy and the right of the child to an open future, and may imply a possible larger responsibility of the clinician towards the welfare of the future child. Combinations of preconception carrier testing and embryo testing may solve some of these ethical questions but could introduce others.
CONCLUSIONS: As comprehensive testing techniques are entering the IVF clinic, there is a need for a thorough rethinking of traditional ethical paradigms regarding medically assisted reproduction.