ESHRE guideline: number of embryos to transfer during IVF/ICSI†.

STUDY QUESTION: Which clinical and embryological factors should be considered to apply double embryo transfer (DET) instead of elective single embryo transfer (eSET)? SUMMARY ANSWER: No clinical or embryological factor per se justifies a recommendation of DET instead of eSET in IVF/ICSI. WHAT IS KNOWN ALREADY: DET is correlated with a higher rate of multiple pregnancy, leading to a subsequent increase in complications for both mother and babies. These complications include preterm birth, low birthweight, and other perinatal adverse outcomes. To mitigate the risks associated with multiple pregnancy, eSET is recommended by international and national professional organizations as the preferred approach in ART. STUDY DESIGN, SIZE, DURATION: The guideline was developed according to the structured methodology for development and update of ESHRE guidelines. Literature searches were performed in PUBMED/MEDLINE and Cochrane databases, and relevant papers published up to May 2023, written in English, were included. Live birth rate, cumulative live birth rate, and multiple pregnancy rate were considered as critical outcomes. PARTICIPANTS/MATERIALS, SETTING, METHODS: Based on the collected evidence, recommendations were discussed until a consensus was reached within the Guideline Development Group (GDG). A stakeholder review was organized after the guideline draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee. MAIN RESULTS AND THE ROLE OF CHANCE: The guideline provides 35 recommendations on the medical and non-medical risks associated with multiple pregnancies and on the clinical and embryological factors to be considered when deciding on the number of embryos to transfer. These recommendations include 25 evidence-based recommendations, of which 24 were formulated as strong recommendations and one as conditional, and 10 good practice points. Of the evidence-based recommendations, seven (28%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (three recommendations; 12%), or very low-quality evidence (15 recommendations; 60%). Owing to the lack of evidence-based research, the guideline also clearly mentions recommendations for future studies. LIMITATIONS, REASONS FOR CAUTION: The guideline assessed different factors one by one based on existing evidence. However, in real life, clinicians' decisions are based on several prognostic factors related to each patient's case. Furthermore, the evidence from randomized controlled trials is too scarce to formulate high-quality evidence-based recommendations. WIDER IMPLICATIONS OF THE FINDINGS: The guideline provides health professionals with clear advice on best practice in the decision-making process during IVF/ICSI, based on the best evidence currently available, and recommendations on relevant information that should be communicated to patients. In addition, a list of research recommendations is provided to stimulate further studies in the field. STUDY FUNDING/COMPETING INTEREST(S): The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, the literature searches, and the dissemination of the guideline. The guideline group members did not receive payment. DPB declared receiving honoraria for lectures from Merck, Ferring, and Gedeon Richter. She is a member of ESHRE EXCO, and the Mediterranean Society for reproductive medicine and the president of the Croatian Society for Gynaecological Endocrinology and Reproductive Medicine. CDG is the past Chair of the ESHRE EIM Consortium and a paid deputy member of the Editorial board of Human Reproduction. IR declared receiving reimbursement from ESHRE and EDCD for attending meetings. She holds an unpaid leadership role in OBBCSSR, ECDC Sohonet, and AER. KAR-W declared receiving grants for clinical researchers and funding provision to the institution from the Swedish Cancer Society (200170F), the Senior Clinical Investigator Award, Radiumhemmets Forskningsfonder (Dnr: 201313), Stockholm County Council FoU (FoUI-953912) and Karolinska Institutet (Dnr 2020-01963), NovoNordisk, Merck and Ferring Pharmaceuticals. She received consulting fees from the Swedish Ministry of Health and Welfare. She received honoraria from Roche, Pfizer, and Organon for chairmanship and lectures. She received support from Organon for attending meetings. She participated in advisory boards for Merck, Nordic countries, and Ferring. She declared receiving time-lapse equipment and grants with payment to institution for pre-clinical research from Merck pharmaceuticals and from Ferring. SS-R received research funding from Roche Diagnostics, Organon/MSD, Theramex, and Gedeo-Richter. He received consulting fees from Organon/MSD, Ferring Pharmaceuticals, and Merck Serono. He declared receiving honoraria for lectures from Ferring Pharmaceuticals, Besins, Organon/MSD, Theramex, and Gedeon Richter. He received support for attending Gedeon Richter meetings and participated in the Data Safety Monitoring Board of the T-TRANSPORT trial. He is the Deputy of ESHRE SQART special interest group. He holds stock options in IVI Lisboa and received equipment and other services from Roche Diagnostics and Ferring Pharmaceuticals. KT declared receiving payment for honoraria for giving lectures from Merck Serono and Organon. She is member of the safety advisory board of EDQM. She holds a leadership role in the ICCBBA board of directors. ZV received reimbursement from ESHRE for attending meetings. She also received research grants from ESHRE and Juhani Aaltonen Foundation. She is the coordinator of EHSRE SQART special interest group. The other authors have no conflicts of interest to declare. DISCLAIMER: This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (full disclaimer available at https://www.eshre.eu/Guidelines-and-Legal).

Evaluating risk, safety and efficacy of novel reproductive techniques and therapies through the EuroGTP II risk assessment tool.

STUDY QUESTION: Can risks associated with novelties in assisted reproduction technologies (ARTs) be assessed in a systematic and structured way? SUMMARY ANSWER: An ART-specific risk assessment tool has been developed to assess the risks associated with the development of novelties in ART (EuroGTP II-ART). WHAT IS KNOWN ALREADY: How to implement new technologies in ART is well-described in the literature. The successive steps should include testing in animal models, executing pre-clinical studies using supernumerary gametes or embryos, prospective clinical trials and finally, short- and long-term follow-up studies on the health of the offspring. A framework categorizing treatments from experimental through innovative to established according to the extent of the studies conducted has been devised. However, a systematic and standardized methodology to facilitate risk evaluation before innovations are performed in a clinical setting is lacking. STUDY DESIGN, SIZE, DURATION: The EuroGTP II-ART risk assessment tool was developed on the basis of a generic risk assessment algorithm developed for tissue and cell therapies and products (TCTPs) in the context of the project 'Good Practices for demonstrating safety and quality through recipient follow-up European Good Tissue and cells Practices II (EuroGTP II)'. For this purpose, a series of four meetings was held in which eight ART experts participated. In addition, several tests and simulations were undertaken to fine-tune the final tool. PARTICIPANTS/MATERIALS, SETTING, METHODS: The three steps comprising the EuroGTP II methodology were evaluated against its usefulness and applicability in ART. Ways to improve and adapt the methodology into ART risk assessment were agreed and implemented. MAIN RESULTS AND THE ROLE OF CHANCE: Assessment of the novelty (Step 1), consisting of seven questions, is the same as for other TCTPs. Practical examples were included for better understanding. Identification of potential risks and consequences (Step 2), consisting of a series of risks and risk consequences to consider during risk assessment, was adapted from the generic methodology, adding more potential risks for processes involving gonadic tissues. The algorithm to score risks was also adapted, giving a specific range of highest possible risk scores. A list of strategies for risk reduction and definition of extended studies required to ensure effectiveness and safety (Step 3) was also produced by the ART experts, based on generic EuroGTP II methodology. Several explanations and examples were provided for each of the steps for better understanding within this field. LIMITATIONS, REASONS FOR CAUTION: A multidisciplinary team is needed to perform risk assessment, to interpret results and to determine risk mitigation strategies and/or next steps required to ensure the safety in the clinical use of novelties. WIDER IMPLICATIONS OF THE FINDINGS: This is a dynamic tool whose value goes beyond assessment of risk before implementing a novel ART in clinical practice, to re-evaluate risks based on information collected during the process. STUDY FUNDING / COMPETING INTEREST(S): This study was called EUROGTP II and was funded by the European Commission (Grant agreement number 709567). The authors declare no competing interests concerning the results of this study.

The prevalence of SARS-CoV-2 antibodies in triage-negative patients and staff of a fertility setting from lockdown release throughout 2020.

STUDY QUESTION: What is the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in triage-negative patients undergoing ART and fertility care providers after lockdown release and throughout 2020? SUMMARY ANSWER: Out of the triage-negative patients whose blood samples were assessed for SARS-CoV-2 antibodies over 6 months, 5.2% yielded positive results with a significantly higher rate in health care workers (HCWs) and a significant month-by-month increase in those with evidence of antibodies. WHAT IS KNOWN ALREADY: Patients of reproductive age are more prone to asymptomatic or minimal forms of coronavirus disease 2019 (COVID-19) as compared to older age groups, and the identification of those with active infection and those already exposed (and probably immunized) is important for safety and cost-effective use of testing resources in the fertility setting. Data on the prevalence of SARS-CoV-2 in ART patients are limited and encompass short time frames; current rates are unknown. There is also no consensus on the optimal way of screening triage-negative ART patients in moderate/high-risk areas. STUDY DESIGN SIZE DURATION: A prospective longitudinal unicentric study on triage negative ART patients (n = 516) and clinical staff (n = 30) was carried out. We analyzed 705 serological tests for SARS-CoV-2 sampled between 17 May 2020 (the first working day after lockdown release) up to 1 December 2020, to assess the positivity rates for SARS-CoV-2 antibodies. PARTICIPANTS/MATERIALS SETTING METHODS: We collected data on the serological status for IgM and IgG antibodies against SARS-CoV-2 in 516 triage-negative men (n = 123) and women (n = 393) undergoing ART at a private fertility center and 30 HCWs that were at work during the study period. Antibodies were detected with a capture chemiluminescence assay (CLIA) targeting the highly Immunogenic S1 and S2 domains on the virus spike protein. We also analyzed the molecular test results of the cases exhibiting a positive serology. MAIN RESULTS AND THE ROLE OF CHANCE: The data showed that 5.2% of the triage-negative ART patients had a positive serological result for SARS-CoV-2, with an overall conversion rate of 2.1% for IgG and 4.6% for IgM. There was no significant difference in seroprevalence between sexes. The small cohort (n = 30) of HCWs had a markedly increased seroprevalence (12.9% for Ig M and 22.6% for IgG). The highest seropositivity in our cohort was recorded in November (16.2%). The IgM positivity rates revealed significant monthly increments, paralleling official prevalence rates based on nasopharyngeal swabs. No positive molecular tests were identified in cases exhibiting a solitary positive IgG result. We show that despite a 6-fold increase in the number of ART patients with a positive serology between May and December 2020, most of our patients remain unexposed to the virus. The study was undertaken in a high-risk area for COVID-19, with a 20-times increase in the active cases across the study period. LIMITATIONS REASONS FOR CAUTION: The geographical restriction, alongside the lack of running a second, differently-targeted immunoassay (orthogonal testing), could limit the generalizability and translation of our results to other fertility settings or other immunoassays. WIDER IMPLICATIONS OF THE FINDINGS: The low positivity rates for IgG against the SARS-CoV-2 spike protein seen at the end of 2020 imply that most of the fertility patients are still at risk for SARS-CoV-2 infection. Until mass vaccination and other measures effectively diminish the pandemic, risk mitigation strategies must be maintained in the fertility units in the foreseeable future. Patients with a solitary IgG+ status are most likely 'non-infectious' and can elude further testing without giving up the strict use of universal protective measures. With increasing seroprevalences owing to infection or vaccination, and with the consecutive increase in test performance, it is possible that serological screening of ART patients might be more cost-effective than PCR testing, especially for the many patients with repeat treatments/procedures in a time-frame of months. STUDY FUNDING/COMPETING INTERESTS: This research received no external funding. All authors declare having no conflict of interest with regard to this trial.

Coding in medically assisted reproduction: the status of the implementation of the Single European Code for reproductive cells and tissues.

STUDY QUESTION: To evaluate the implementation of the coding systems in medically assisted reproduction (MAR) centres in the European Union (EU). SUMMARY ANSWER: Our data show that a significant number of MAR centres use the Single European Code (SEC), but it also shows certain limitations to the coding. WHAT IS KNOWN ALREADY: Traceability and identification of tissue and cells used for clinical application are extremely important as it is one of the key aspects of quality and safety both for the donors and the recipients. Patients as well as tissues and cells move across the European continent and far beyond, hence a uniform coding system was very much needed. The coding of tissues and cells from human origin was already embedded in the EU directives 2004/23/EC. The use of the Single European Code (SEC) on tissues and cells was enforced in 2017 for tissues and cells distributed within the EU or exported from the EU. The SEC ensures standardization within the EU, allowing the integration of the two existing codes (ISBT-128 and Eurocode) within the SEC structure. Likewise, in the MAR field, the SEC was launched in order to ensure the traceability of reproductive tissues and cells. Gametes and embryos from partner donation as well as reproductive cells and tissues of allogeneic donation were excluded from the SEC as long as they remain in the centre of origin. STUDY DESIGN SIZE DURATION: A cross-sectional survey aimed to gain insight into the use of SEC by MAR centres was conducted between 5 November and 15 December 2018. PARTICIPANTS/MATERIALS SETTING METHODS: The online survey was distributed among the ESHRE members. MAIN RESULTS AND THE ROLE OF CHANCE: The survey results highlight the strengths and weaknesses in the practical use of the SEC. The data from the survey showed that the SEC code is something that is known in the MAR field. Our data showed that over half of the respondents were using the SEC in their centre. On the other hand, there is also criticism about the use of SEC in MAR, especially that the added value for traceability and identification in ART is found to be rather limited. LIMITATIONS REASONS FOR CAUTION: The survey response rate was rather low (4.84%). The view of the use of SEC discussed in this paper still provides insight into the use of the SEC in several MAR centres. WIDER IMPLICATIONS OF THE FINDINGS: The survey highlights some knowledge gaps concerning coding. This information can be used to develop tools to increase knowledge of the SEC. STUDY FUNDING/COMPETING INTERESTS: There was no external funding for this study. The authors declare that they have no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.