Social egg freezing: Motivations, treatment experiences and the impact of Covid-19 - a single-center experience.

INTRODUCTION: This study aims to assess the motivations and treatment experiences of women undergoing social egg freezing and to understand the impact of the Covid-19 pandemic. MATERIAL AND METHODS: Between January 2011 to December 2021, 191 social egg freezing patients were recruited from the Lister Fertility Clinic, London UK. Participants completed a validated questionnaire investigating patients' perspectives of social egg freezing. A response rate of 46.6% was achieved. RESULTS: In all, 93.9% of women expressed concern regarding age-related fertility decline which influenced their decision to undergo social egg freezing. The majority (89.5%) of women were not in a relationship at the time of social egg freezing and considered this a motivating factor. Also, 39.0% of participants had side effects related to treatment which affected work and social life. Participants were significantly more likely to experience side effects if they underwent multiple egg freezing cycles (χ2 , p < 0.01) or if they cryopreserved oocytes during the COVID-19 pandemic (χ2 , p < 0.05). Of the women, 64.0% wished to have cryopreserved oocytes at a younger age, a view significantly more likely if older than 37 years at first social egg freezing cycle (χ2 , p < 0.001). Also, 82.3% of women reported their decision to undergo social egg freezing was not delayed due to concerns regarding COVID-19 exposure during treatment; 44.1% considered the pandemic made them more willing to undergo social egg freezing. CONCLUSIONS: Most participants did not regret their decision to undergo social egg freezing but the majority wished they had cryopreserved oocytes at a younger age. This highlights the importance of early education to optimize outcomes and patient choice. The egg freezing process can be stressful, women may have concerns around social egg freezing and unprecedented situations such as the COVID-19 pandemic may alter treatment experience.

Does mRNA COVID-19 vaccination in oocyte donors impact ovarian stimulation parameters or IVF outcomes for recipients?

RESEARCH QUESTION: What is the effect of mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in young oocyte donors in terms of ovarian response to stimulation, fertilization rate, embryo development and clinical outcomes in recipients? DESIGN: This retrospective, multicentre cohort study evaluated 115 oocyte donors who had undergone at least two ovarian stimulation protocols (before and after complete SARS-CoV-2 vaccination) between November 2021 and February 2022. Comparisons were made of the primary outcomes of days of stimulation, total dose of gonadotrophins and laboratory performance in ovarian stimulation in oocyte donors before and after vaccination. A total of 136 cycles in matched recipients were analysed as secondary outcomes and, from those, 110 women received a fresh single-embryo transfer, with analysis of biochemical ß-human chorionic gonadotrophin concentrations and rates of clinical pregnancy with heartbeat. RESULTS: Longer stimulation was required in the post-vaccination than pre-vaccination group (10.31 ± 1.5 versus 9.51 ± 1.5 days; P < 0.001) along with higher gonadotrophin consumption (2453.5 ± 740 versus 2235.5 ± 615 IU; P < 0.001) with a similar starting dose of gonadotrophins in both groups. More oocytes were retrieved in the post-vaccination group (16.62 ± 7.1 versus 15.38 ± 7.0; P = 0.02). However, the number of metaphase II (MII) oocytes was similar between groups (pre-vaccination 12.61 ± 5.9 versus post-vaccination 13.01 ± 6.6; P = 0.39) and the ratio of MII/retrieved oocytes favoured the pre-vaccination group (0.83 ± 0.1 versus 0.77 ± 0.2 post-vaccination; P = 0.019). In recipients with a similar number of provided oocytes, the fertilization rate, total number of obtained blastocysts, number of top-quality blastocysts, and rates of biochemical pregnancy and clinical pregnancy with heartbeat were not significantly different between groups. CONCLUSIONS: This study shows no adverse influence of mRNA SARS-CoV-2 vaccination on ovarian response in a young population.

Telomeres and oocyte maturation rate are not reduced by COVID-19 except in severe cases.

In brief: COVID-19 does not affect the telomeres or fertility outcomes in mild cases. However, in women with severe symptoms, telomeres of granulosa cells are shorter, and the oocyte maturation rate is decreased. Abstract: The coronavirus SARS-CoV-2 causes COVID-19 disease and affects primarily the lungs and also other organs, causing accelerated cell aging. One of the main pathways involved in aging is telomere attrition, which ultimately leads to defective tissue regeneration and organ dysfunction. Indeed, short telomeres in aged people aggravate the COVID-19 symptoms, and COVID-19 survivors showed shorter telomeres in blood cells. The SARS-CoV-2 has been detected in testis, but the ovaries, which express the viral entry factors, have not been fully explored. Our objective was to analyze telomeres and reproductive outcomes in women who had COVID-19 and controls. In this prospective cohort study, granulosa cells (GCs) and blood were collected from 65 women. Telomere length (TL) was measured by high-throughput in situ hybridization. Mean TL of GCs and peripheral blood mononuclear cells (PBMCs) was alike in control and mild cases. However, mean TL of GCs was lower in severe cases compared to controls (P = 0.017). Control and COVID groups had similar ovarian reserve and number of total oocytes after puncture. However, the oocyte maturation rate was lower in severe cases (P = 0.018). Interestingly, a positive correlation between the oocyte maturation rate and TL of GCs was found in the control group (P = 0.024). Our findings point to a potential impact of the coronavirus infection on telomeres and reproductive outcomes in severe cases. This might be considered upon possible new SARS-CoV threats, to favor treatments that enhance oocyte maturation in women severely affected by coronavirus undergoing ART.

Cryobanking European Mink (Mustela lutreola) Mesenchymal Stem Cells and Oocytes.

The European mink (Mustela lutreola) is one of Europe's most endangered species, and it is on the brink of extinction in the Iberian Peninsula. The species' precarious situation requires the application of new ex situ conservation methodologies that complement the existing ex situ and in situ conservation measures. Here, we report for the first time the establishment of a biobank for European mink mesenchymal stem cells (emMSC) and oocytes from specimens found dead in the Iberian Peninsula, either free or in captivity. New emMSC lines were isolated from different tissues: bone marrow (emBM-MSC), oral mucosa (emOM-MSc), dermal skin (emDS-MSC), oviduct (emO-MSc), endometrium (emE-MSC), testicular (emT-MSC), and adipose tissue from two different adipose depots: subcutaneous (emSCA-MSC) and ovarian (emOA-MSC). All eight emMSC lines showed plastic adhesion, a detectable expression of characteristic markers of MSCs, and, when cultured under osteogenic and adipogenic conditions, differentiation capacity to these lineages. Additionally, we were able to keep 227 Cumulus-oocyte complexes (COCs) in the biobank, 97 of which are grade I or II. The European mink MSC and oocyte biobank will allow for the conservation of the species' genetic variability, the application of assisted reproduction techniques, and the development of in vitro models for studying the molecular mechanisms of infectious diseases that threaten the species' precarious situation.

Fluorescence-Based Measurements of Membrane-Bound Angiotensin Converting Enzyme 2 Activity Using Xenopus Laevis Oocytes.

Functional investigations of enzymes involving cellular expression systems are important for pharmacological studies. The precise control of expression is challenging in transiently transfected mammalian cell lines. Here, we explored the ability of Xenopus laevis oocytes to express a membrane-bound enzyme for functional characterization using standard 96-well plates and a fluorescence-based plate reader assay. We microinjected oocytes with cRNA encoding the angiotensin converting enzyme 2 (ACE2) and measured the enzymatic activity in single oocytes using a commercial fluorescence-based assay. The injected oocytes showed up to a 50-fold increase in fluorescence compared to uninjected oocytes. This fluorescence intensity was dose-dependent on the amount of ACE2 cRNA. These results suggest that Xenopus oocytes can be used for the functional evaluation of membrane-bound enzymes, decreasing the experimental workload.

Pfizer SARS-CoV-2 BNT162b2 mRNA vaccination (BNT162b2) has no adverse effect on elective oocyte cryopreservation outcomes.

RESEARCH QUESTION: Do elective oocyte cryopreservation outcomes in women 1-13 months after SARS-CoV-2 vaccination alter compared with unvaccinated women and do different time intervals between vaccination and ovarian stimulation impact these outcomes? DESIGN: This retrospective cohort study, conducted in a university-affiliated IVF centre, included 232 elective oocyte cryopreservation cycles of vaccinated and unvaccinated patients, without previous infection with the SARS-CoV-2 virus, between December 2020 and January 2022. Two control groups - pre-pandemic (January 2019 to February 2020) and intra-pandemic (December 2020 to January 2022) unvaccinated groups - were compared with the vaccinated group, further divided into four subgroups (under 3, 3-6, 6-9 and 9-13 months). The primary outcome was the elective oocyte cryopreservation cycle outcomes - number of retrieved and number of mature oocytes. RESULTS: The vaccinated group demonstrated comparable outcomes with regards to number of retrieved and mature oocytes compared with the pre-pandemic and intra-pandemic unvaccinated groups (12.6 ± 8.0 versus 13.0 ± 8.2 and 12.5 ± 7.4 retrieved and 10.1 ± 6.9 versus 9.5 ± 6.4 and 10.1 ± 6.3 mature oocytes, respectively; not significant for both). Similar results were noted in a comparison between the intra-pandemic unvaccinated group and the four vaccinated subgroups. No correlation was found between the parameter of days from vaccination and cycle outcomes. Similarly, analysis of covariance showed no association between vaccination status and timing and number of mature oocytes. CONCLUSIONS: The SARS-CoV-2 vaccination does not alter the outcomes of elective oocyte cryopreservation procedures. This is true even in a relatively long time interval of 9 to 13 months from vaccination.

Pleiotropic Effects of IGF1 on the Oocyte.

A woman's endocrine system plays a crucial role in orchestrating cellular interactions throughout her life. The growth hormone (GH) and insulin-like growth factor (IGF) system appears to impact crucial reproductive events and cell types of the ovary, such as granulosa cells, theca cells, and oocytes. Further, IGF1 is a cornerstone during embryonic development and influences predominantly developing and pre-antral follicles. In this commentary, we will emphasize the pleiotropic effects of IGF1 on physiological processes inside the egg. Herein, we will provide a brief overview on IGF1 related cell signal transduction pathways during the maturation and aging of oocytes. We aim to elucidate from a molecular and biochemical point of view if IGF1 in women with metabolic imbalances such as obesity or diabetes could be used in clinics as a novel, reliable estimator for the developmental competence of an oocyte.

The use of oocyte cryopreservation for fertility preservation in patients with sex chromosome disorders: a case series describing outcomes.

PURPOSE: Characterize outcomes among adolescents and young adults (AYAs) with sex chromosome disorders (SCDs) after oocyte cryopreservation (OC) consultation. METHODS: Retrospective case series of all AYA (< 25 years) patients with SCDs seen for OC consultation from 2011 to 2019 at a large, urban, academic fertility center. All AYA patients with an SCD seen for OC consult in the study time period were reviewed and included. Data collected included patient age, SCD type, number of patients who attempted OC, number of cycles attempted, and cycle outcomes. RESULTS: Twenty-two patients were included: 9 with Turner syndrome, 12 with mosaic Turner syndrome, and 1 with 47,XXX. Mean age at consult was 14.7 ± 3.5 years. Fourteen patients elected for OC: 5 with Turner syndrome, 8 with mosaic Turner syndrome, and 1 47,XXX who pursued 31 OC cycles total. Of those 14 patients, 10 underwent retrieval, 9 froze oocytes, and 8 froze mature (MII) oocytes. Seven patients underwent > 1 cycle and 7 had ≥ 1 cancelation. 3/3 patients who pursued cycles after 1st cancelation never got to retrieval. Age, SCD type, and baseline FSH did not predict ability to freeze MIIs. One patient returned after OC and attempted 4 ovulation induction cycles and 2 IVF cycles; all were canceled for low response. CONCLUSIONS: AYA patients with SCDs have a high risk of poor response and cycle cancelation but the majority froze MIIs. Thus, setting expectations is important. A larger sample size is needed to evaluate possible clinical predictors of success.

Does mRNA SARS-CoV-2 vaccine in the follicular fluid impact follicle and oocyte performance in IVF treatments?

PROBLEM: The COVID-19 pandemic has many clinical manifestations. Rapid vaccine development raised concerns and speculations about future fertility outcomes and vaccine safety. We evaluated the effect of Pfizer-BioNTech mRNA SARS-CoV-2 vaccine on IVF treatment, oocyte and embryo quality, and pregnancy outcomes. METHOD OF STUDY: This prospective, observational cohort study was conducted in a referral IVF Unit, 3/2021-5/2021. We aimed to recruit all women undergoing IVF/ICSI cycles from 3/1-4/30/2021, 2-8 weeks after the second vaccination, and to analyze 50-60 samples in the 2-month period. Patients were categorized according to serum antibody levels: positive for spike (S), positive for nucleotide (N), or negative for both. On the day of ovum pick-up, follicular fluid and blood samples were analyzed for anti-nucleotide (anti-N) antibodies, and anti-spike (anti-S) antibodies, hormonal profile, C-reactive protein (CRP) and other metabolic parameters. RESULTS: Of 59 women enrolled, 37 reported being vaccinated and 22 were not. We found 97% correlation between anti-S and anti-N in the blood and the follicular fluid. Follicular fluid was analyzed based on antibody categorization. All IVF treatment parameters in the follicular fluids and serum were comparable, except CRP was significantly elevated among patients with anti-N antibodies (2.29 [1.42-6.08] vs. 4.11 [1.62-5.75] vs. 1.44 [.36-8.33]; p < .001). Pregnancy outcomes were comparable (44% vs. 33% vs. 50%; p = .97). CONCLUSION: mRNA SARS-CoV-2 vaccine did not appear to affect treatment outcomes or ovarian reserves in the subsequent IVF cycle.

[French clinical practice guidelines developed by a modified Delphi consensus process for oocyte vitrification in women with benign gynecologic disease]. / Indications de vitrification ovocytaire dans les pathologies gynécologiques bénignes : conseils de bonne pratique du CNGOF après étude de consensus par méthode Delphi.

OBJECTIVES: To provide clinical practice guidelines about fertility preservation (FP) for women with benign gynecologic disease (BGD) developed by a modified Delphi consensus process for oocyte vitrification in women with benign gynecologic disease. METHODS: A steering committee composed of 14 healthcare professionals and a patient representative with lived experience of endometriosis identified 42 potential practices related to FP for BGD. Then 114 key stakeholders including various healthcare professionals (n=108) and patient representatives (n=6) were asked to participate in a modified Delphi process via two online survey rounds from February to September 2020 and a final meeting. Due to the COVID-19 pandemic, this final meeting to reach consensus was held as a videoconference in November 2020. RESULTS: Survey response of stakeholders was 75 % (86/114) for round 1 and 87 % (75/86) for round 2. Consensus was reached for the recommendations for 28 items, that have been distributed into five general categories: (i) Information to provide to women of reproductive age with a BGD, (ii) Technical aspects of FP for BGD, (iii) Indications for FP in endometriosis, (iv) Indications for FP for non-endometriosis BGD, (v) Indications for FP after a fortuitous diagnosis of an idiopathic diminished ovarian reserve. CONCLUSION: These guidelines provide some practice advice to help health professionals better inform women about the possibilities of cryopreserving their oocytes prior to the management of a BGD that may affect their ovarian reserve and fertility. STUDY FUNDING/COMPETING INTEREST(S): The CNGOF (Collège National des Gynécologues Obstétriciens Français) funded the implementation of the Delphi process.

The Effects of SARS-CoV-2 Infection on Female Fertility: A Review of the Literature.

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.

Regulation of epithelial sodium channel activity by SARS-CoV-1 and SARS-CoV-2 proteins.

Severe acute respiratory syndrome (SARS) coronavirus (CoV) 2 (SARS-CoV-2), which causes the coronavirus disease 2019, encodes several proteins whose roles are poorly understood. We tested their ability either to directly form plasma membrane ion channels or to change functions of two mammalian plasma membrane ion channels, the epithelial sodium channel (ENaC) and the α3ß4 nicotinic acetylcholine receptor. In mRNA-injected Xenopus oocytes, none of nine SARS-CoV-2 proteins or two SARS-CoV-1 proteins produced conductances, nor did co-injection of several combinations. Immunoblots for ORF8, spike (S), and envelope (E) proteins revealed that the proteins are expressed at appropriate molecular weights. In experiments on coexpression with ENaC, three tested SARS proteins (SARS-CoV-1 E, SARS-CoV-2 E, and SARS-CoV-2 S) markedly decrease ENaC currents. SARS-CoV-1 S protein decreases ENaC currents modestly. Coexpressing the E proteins but not the S proteins with α3ß4 nicotinic acetylcholine receptors significantly reduces acetylcholine-induced currents. ENaC inhibition does not occur if the SARS-CoV protein mRNAs are injected 24 h after the ENaC mRNAs, suggesting that SARS-CoV proteins affect early step(s) in functional expression of channel proteins. Consistent with the hypothesis that the SARS-CoV-2 S protein-induced ENaC inhibition involves competition for available protease, mutating the furin cleavage site in SARS-CoV-2 S protein partially relieves inhibition of ENaC currents. Extending previous suggestions that SARS proteins affect ENaC currents via protein kinase C (PKC) activation, PKC activation via phorbol 12-myristate 13-acetate decreases ENaC and α3ß4 activity. Phorbol 12-myristate 13-acetate application reduced membrane capacitance ∼5%, presumably via increased endocytosis, but this decrease is much smaller than the SARS proteins' effects on conductances. Also, incubating oocytes in Gö-6976, a PKCα and PKCß inhibitor, did not alter E or S protein-induced channel inhibition. We conclude that SARS-CoV-1 and SARS-CoV-2 proteins alter the function of human plasma membrane channels, via incompletely understood mechanisms. These interactions may play a role in the coronavirus 2019 pathophysiology.

The N501Y Mutation of SARS-CoV-2 Spike Protein Impairs Spindle Assembly in Mouse Oocytes.

The COVID-19 pandemic has been continuing for one and a half year and caused a profound effect on human health. Although advanced researches and literatures are gathered, the influences of SARS-CoV-2 on the reproduction systems are largely unknown, especially on the female reproductive functions. The purpose of this study was to investigate the effect of N501Y mutant spike protein of SARS-Cov-2 on oocyte maturation. We demonstrated that the N501Y mutant of SARS-CoV-2 spike protein impaired the mouse oocyte maturation accompanied by abnormal spindle assembly. Furthermore, the mean spindle length and the plate width were significantly increased in the N501Y-treated group compared to the control group. These results indicated the potential impairment of maturation of the oocytes caused by the infection of SARS-CoV-2, albeit current results were derived from mouse oocytes. The present study provided a theoretical basis for the attention of female reproductive health during the COVID-19 pandemic and shed light on the potential risk of SARS-CoV-2 in the successful rate of assisted reproduction.

Different CO2 settings (6.0% vs 7.0%) do have an impact on extracellular pH of culture medium (pHe) and euploidy rates rather than on blastocyst development: a sibling oocyte study.

OBJECTIVE: To determine whether euploidy rates and blastocyst development differ in a continuous culture medium under different CO2 concentrations. DESIGN AND METHOD: A single-center retrospective study was performed from July 2018 to October 2019 including 44 fresh cycles with at least four fresh mature oocytes (MII) without severe male factor infertility. Sibling MII were injected and cultured in Global®Total®LP under 6.0% (pHe = 7.374 ± 0.014) or 7.0% (pHe = 7.300 ± 0.013) CO2, 5.0% O2, and 89.0% or 88.0% N2. Analyzed variables were normally fertilized oocytes (2PN), cleavage rate, blastulation rate on day 5/2PN, usable blastocyst (blastocysts biopsied/2PN), and euploidy rates. Blastocyst's trophectoderm biopsy was performed on day 5, 6, or 7 for genetic testing and mitochondrial DNA (mtDNA) quantification by next-generation sequencing. RESULTS: Women's mean age was 33.0 ± 6.6 years old. From a total of 604 MII, no differences were found in normal fertilization and cleavage rates on day 3 between 6.0 and 7.0% CO2 (72.3% vs 67.1%, p = 0.169 and 96.6% vs 96.3%, p = 0.897, respectively). Blastulation rate on day 5/2PN was comparable between 6.0 and 7.0% CO2 (68.1% vs 64.2%, p = 0.409). Although usable blastocyst rate was not different (54.3% vs 55.3%, p = 0.922), total euploidy rates differed significantly (58.7% vs 42.8%, p = 0.016) between 6.0% and 7.0% CO2, respectively. The mean blastocyst mtDNA content was significantly lower in 6.0% CO2 (30.4 ± 9.1 vs 32.9 ± 10.3, p = 0.037). CONCLUSION: Blastocyst development is not affected when embryos are cultured in vitro at 6.0% or 7.0% CO2, while euploidy rates are significantly decreased at a higher CO2 concentration, therefore at a lower pHe.

SARS-CoV-2 infection negatively affects ovarian function in ART patients.

Several organs, such as the heart, breasts, intestine, testes, and ovaries, have been reported to be target tissues of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To date, no studies have demonstrated SARS-CoV-2 infection in the female reproductive system. In the present study, we investigated the effects of SARS-CoV-2 infection on ovarian function by comparing follicular fluid (FF) from control and recovered coronavirus disease 2019 (COVID-19) patients and by evaluating the influence of these FF on human endothelial and non-luteinized granulosa cell cultures. Our results showed that most FFs (91.3%) from screened post COVID-19 patients were positive for IgG antibodies against SARS-CoV-2. Additionally, patients with higher levels of IgG against SARS-CoV-2 had lower numbers of retrieved oocytes. While VEGF and IL-1ß were significantly lower in post COVID-19 FF, IL-10 did not differ from that in control FF. Moreover, in COV434 cells stimulated with FF from post COVID-19 patients, steroidogenic acute regulatory protein (StAR), estrogen-receptor ß (Erß), and vascular endothelial growth factor (VEGF) expression were significantly decreased, whereas estrogen-receptor α (ERα) and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) did not change. In endothelial cells stimulated with post COVID-19 FF, we observed a decrease in cell migration without changes in protein expression of certain angiogenic factors. Both cell types showed a significantly higher γH2AX expression when exposed to post COVID-19 FF. In conclusion, our results describe for the first time that the SARS-CoV-2 infection adversely affects the follicular microenvironment, thus dysregulating ovarian function.

Spatio-temporal mRNA tracking in the early zebrafish embryo.

Early stages of embryogenesis depend on subcellular localization and transport of maternal mRNA. However, systematic analysis of these processes is hindered by a lack of spatio-temporal information in single-cell RNA sequencing. Here, we combine spatially-resolved transcriptomics and single-cell RNA labeling to perform a spatio-temporal analysis of the transcriptome during early zebrafish development. We measure spatial localization of mRNA molecules within the one-cell stage embryo, which allows us to identify a class of mRNAs that are specifically localized at an extraembryonic position, the vegetal pole. Furthermore, we establish a method for high-throughput single-cell RNA labeling in early zebrafish embryos, which enables us to follow the fate of individual maternal transcripts until gastrulation. This approach reveals that many localized transcripts are specifically transported to the primordial germ cells. Finally, we acquire spatial transcriptomes of two xenopus species and compare evolutionary conservation of localized genes as well as enriched sequence motifs.

Ovotoxicity of smoking and impact on AMH levels: a pilot study.

OBJECTIVE: Our study aims to analyze the correlation between the decrease of ovarian reserve and lower oocyte quality produced by the follicle associated with use of tobacco. In particular, the study analyzed the potential effects of cigarette smoking on hormonal dosages in infertile patients and patients with recurrent miscarriages. PATIENTS AND METHODS: This retrospective study included 61 women with a history of infertility and recurrent miscarriage between March 2016 and March 2019 selected at the clinic of poly-abortivity and infertility at the ASL Roma 2 - Department of Obstetrics and Gynecology, "S. Eugenio" Hospital. Patients' medical history (familiar, physiological and pathological with particular attention to smoking habits and nutrition), the obstetric history, gynecological examination and ultrasound were recorded. The serum concentration of FSH, AMH, Inhibin B were examined between the second and third day of the period. RESULTS: A total of 61 patients between 25 and 43 years of age admitted into our clinic were identified; 42 patients with a history of recurrent abortion (more than two abortions) and 19 patients with a history of infertility were selected. A total of 31 non-smokers women (50.82%) (G1) and 30 (49.18%) (G2) smokers were included. No differences were detected between the two groups under examination; the parameter that did appear discordant is the AMH value; this value scored higher in non-smokers than in smokers. Specifically, in smoker patients with recurrent abortions. CONCLUSIONS: The connection between nicotine, combustion material, and oocyte quality is an important and controversial research topic. Further studies are needed to clarify the influence of nicotine and combustion on the ovarian reserve in order to identify the main risk factors.

SARS-CoV-2 host receptors ACE2 and CD147 (BSG) are present on human oocytes and blastocysts.

PURPOSE: To visualize SARS-CoV-2 host receptors ACE2 and CD147 on human oocytes and blastocysts. METHODS: Immunohistochemistry and confocal microscopy on human primary oocytes and pre (5 days post fertilization (dpf5) and (dpf6))- and peri (dpf7)-implantation blastocysts donated to research. RESULTS: SARS-CoV-2 host receptors ACE2 and CD147 are present on the membrane of trophectoderm, epiblast and hypoblast cells in human blastocysts. CD147 is also present on the oolemma. CONCLUSION: Theoretically, the earliest stages of embryonic development may be vulnerable for SARS-CoV-2 infection.

Development of Optimized Vitrification Procedures Using Closed Carrier System to Improve the Survival and Developmental Competence of Vitrified Mouse Oocytes.

The open carrier system (OC) is used for vitrification due to its high efficiency in preserving female fertility, but concerns remain that it bears possible risks of cross-contamination. Closed carrier systems (CC) could be an alternative to the OC to increase safety. However, the viability and developmental competence of vitrified/warmed (VW) oocytes using the CC were significantly lower than with OC. We aimed to improve the efficiency of the CC. Metaphase II oocytes were collected from mice after superovulation and subjected to in vitro fertilization after vitrification/warming. Increasing the cooling/warming rate and exposure time to cryoprotectants as key parameters for the CC effectively improved the survival rate and developmental competence of VW oocytes. When all the conditions that improved the outcomes were applied to the conventional CC, hereafter named the modified vitrification/warming procedure using CC (mVW-CC), the viability and developmental competence of VW oocytes were significantly improved as compared to those of VW oocytes in the CC. Furthermore, mVW-CC increased the spindle normality of VW oocytes, as well as the cell number of blastocysts developed from VW oocytes. Collectively, our mVW-CC optimized for mouse oocytes can be utilized for humans without concerns regarding possible cross-contamination during vitrification in the future.

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.