Oocyte Activation Failure: Physiological and Clinical Aspects

Despite successful treatment of infertility with assisted reproductive technology (ART), total fertilization failure (TFF) after in vitro fertilization (IVF) and even after intracytoplasmic sperm injection (ICSI) still occurs. In the current chapter, the incidence and etiology of TFF after ICSI are described. The literature on physiology of oocyte activation, electrical properties of gametes’ membranes, and ion currents is reviewed. Calcium oscillations play an essential role in fertilization, and calcium ions act as secondary messengers in different metabolic pathways and cellular processes during oocyte activation. The contribution of oocyte- and sperm-related causes of fertilization failure is discussed. Many studies on the physiology of fertilization in mammals have shown that oocyte activation is triggered by the sperm factor. Methods for artificial oocyte activation (AOA) try to bypass fertilization failure by influencing physiological processes that are crucial for successful fertilization. Activation can be induced with the use of electrical, mechanical, or chemical stimuli that elevate intracellular concentrations of calcium ions. Different AOA methods and their success and safety are presented

From glass to life: a commentary on the assessment of the reproductive potential of cryopreserved human oocytes

© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Oocyte cryopreservation is one of the more recently established methods of assisted reproduction technologies (ART). Vitrifcation procedures have helped to overcome most technical difculties enabling better oocyte survival after warming. There are diferent indications for oocyte cryopreservation. The technology can be used if the partner fails to produce sperm for an IVF treatment on the day of oocyte collection. For patients at risk of ovarian hyperstimulation syndrome (OHSS), we could also opt not only for “freeze-all embryos” but possibly also for “freeze-all oocytes.” Also, women who may have no partner or may lose their fertility potential due to surgery, chemotherapy, radiotherapy, autoimmune diseases, medical conditions causing ovarian insuffciency, or hematopoietic stem cell transplantation could store their oocytes for future use. Planned oocyte cryopreservation can also be used as a tool to help mitigate age-related fertility decline regardless of whether a patient is partnered. All such procedures raise questions both to patients and healthcare professionals: Can we predict the chance for the parenthood from one medically assisted reproduction (MAR) cycle with cryopreserved oocytes? What is the minimal number of cryopreserved oocytes needed to have a reasonable likelihood of success? Is there an upper age limit for women to store their oocytes?The paper is a part of research programme P3-0327 funded by the Slovenian Research Agency.info:eu-repo/semantics/publishedVersio

POBOLJŠANA STOPA OPLODNJE I POROD INJICIRANJEM POTPUNO NEPOKRETNIH SPERMATOZOIDA ODABRANIH HIPOOSMOTSKIM TESTOM NABREKNUĆA U CITOPLAZMU JAJNE STANICE

In vitro fertilization procedures can be applied to aid infertile couples with complete asthenozoospermia, i.e. with absence of even a single motile sperm in ejaculate. However, the probability of conception with intracytoplasmic injection of sperm (ICSI), selected at random from an immotile sperm sample, is quite slight. In couples, in which the male partner’s ejaculate contained only immotile sperm, the hypo-osmotic swelling (HOS) test was used to select viable sperm for the ICSI procedure. Material and methods. Complete asthenozoospermia as the major cause of infertility was diagnosed in 4 couples, of which two male partners had a special form of complete immotility, a sperm stump defect. Out of the total of 10 hormone-stimulated ICSI cycles, in 6 cycles the sperm for ICSI were chosen randomly, without a HOS test. In 4 cycles, the washed semen samples were incubated in a hypo-osmotic solution and only HOS-positive sperm (i.e. sperm with swollen tail) were used for ICSI. Results. Of 6 ICSI cycles without selection of viable sperm using the HOS test, total fertilization failure was noted in 3. Only a total of 20.7% (6/29) oocytes were fertilized. In all 4 ICSI cycles with performed HOS test prior to sperm injection, embryos for transfer were obtained. An 81.8% (18/22) fertilization rate was registered and one twin pregnancy which resulted in a birth of a healthy singleton. Conclusion. We can confirm that also in cases of complete asthenozoospermia, even in those, combined with stump defect, good fertilization rate and pregnancies can be achieved after selecting the viable sperm by HOS test prior to the ICSI procedure.Oplodnja izvan tijela može se upotrijebiti u liječenju neplodnosti uzrokovane potpunom nepokretljivošću spermatozoida. Naravno, vjerojatnost za začeće nakon oplodnje spermatozoidom koji je slučajno odabran za injiciranje u citoplazmu jajne stanice (ICSI), prilično je nesigurna. U parova, u kojih u ejakulatu nalazimo samo nepokretne spermatozoide, hipoosmotski test nabreknuća repa spermatozoida hypo-osmotic swelling (HOS) test, upotrebljen je za selekciju vitalnih spermatozoida za ICSI. Materijal i metode. Potpuni izostanak pokretljivosti spermatozoida dijagnosticiran je kao glavni uzrok neplodnosti u 4 para. Među njima, kod dvojice muškaraca ustanovljen je poseban oblik potpune nepokretljivosti uzrokovan defektom ostatka repa. Od 10 hormonima stimuliranih ICSI ciklusa, u 6 ciklusa su spermatozoidi za ICSI izabirani nasumce bez HOS testa. U 4 pacijenta oprani spermatozoidi su inkubirani u hipoosmotskoj otopini i samo HOS pozitivni spermatozoidi (spermatozoidi s nabreklim repom), upotrebljeni su za ICSI. Rezultati. Od 6 ICSI ciklusa bez učinjene selekcije spermatozoida HOS testom, potpuni izostanak oplodnje zabilježen je u 3 ciklusa. U preostala 3 ciklusa samo 20,7% (6/29) jajnih stanica je oplođeno. U sva 4 ICSI ciklusa u kojima je pred njihovim injiciranjem za odabir spermatozoida upotrijebljen HOS test, stvoreni su zameci primjereni za prijenos u maternicu. Zabilježena je stopa oplodnje¬ jajnih stanica od 81,8% (18/22), a nakon prijenosa zametka zabilježena je implantacija dva zametka i rođenje jednog zdravog djeteta. Zaključak. U slučajevima potpune nepokretljivosti spermatozoida, čak i u pacijenata gdje je uzrok neplod¬nosti nedostatak struktura repa spermatozoida, možemo očekivati dobru stopu oplodnje i trudnoće nakon selekcije spermatozoida HOS testom

ESHRE certification of ART centres for good laboratory and clinical practice

STUDY QUESTION: Three years after the start of the ESHRE ART Centre Certification (ARTCC) programme, what is the current state of the system, in terms of the interest expressed in it and experiences during the assessment of ART services? SUMMARY ANSWER: As of 1 December 2021, 25 European ART centres have been involved in the various stages of certification and the most common recommendations from inspectors were the need for documented training, verification of competencies for all staff members, verification of laboratory and clinical performance indicators, implementation of a quality management system and avoidance of overusing ICSI and add-ons. WHAT IS KNOWN ALREADY: European Union (EU) legislation has included ART activities in the EU Tissue and Cells Directives (EUTCDs). Following inspections by national EUTCD authorities, many details regarding documentation, laboratory environment, handling of reproductive cells and tissues, traceability, coding and patient testing have become standardized. However, the EUTCDs do not cover all ART-specific aspects. For this reason, the ARTCC was established to focus on peculiar areas, including relevant staff qualifications, training, continuing professional development, workload, equipment suitability, (non)-evidence-based laboratory and clinical methods used, treatment approaches according to ESHRE guidelines, recommendations and laboratory and clinical key performance indicators. STUDY DESIGN, SIZE, DURATION: The article reviews the state-of-the-art of the ESHRE certification of ART centres for good clinical and laboratory practice over an initial 3-year period of operation, including the number of ART centres involved in the different stages of certification and the most common recommendations by inspectors. PARTICIPANTS/MATERIALS, SETTING, METHODS: In 2016, the ARTCC working group began to establish a new ESHRE ARTCC programme. Since then, the working group has organized 4 preparatory courses and appointed 37 inspectors (19 clinicians, 17 embryologists and one paramedical). A tool to verify compliance with ESHRE recommendations for good laboratory and clinical practice was developed. The ARTCC has been open for applications since September 2018. In Step 1, the applicant enters basic information about the ART centre, staff and ART activities into the application platform. After review and approval, the applicant is given the opportunity to enter Step 2 and provide detailed online checklists on general, laboratory, clinical services and clinical outcomes. Two inspectors (one clinician and one embryologist) independently evaluate the submitted checklists. The condition to proceed to evaluation is a positive mean score (at least 66%) from each of the four checklists. In Step 3, a live site visit (or virtual owing to the coronavirus disease 2019 (COVID-19) pandemic) is organized and the inspectors prepare a final report with appropriate recommendations. The application may be rejected at any time if the criteria required to advance to the next stage are not met. The ARTCC programme is currently available for European countries listed in ESHRE internal rules, available on the ESHRE website. The certificate is valid for 3 years, after which an application for renewal can be submitted. MAIN RESULTS AND THE ROLE OF CHANCE: Over a 3-year period (until 1 December 2021), 63 ART centres from 25 countries started applying through an online platform. So far, 38 applications did not progress owing to lack of completion of the initial application within a 1-year period or because applications came from non-European countries. Of the remaining 25 applications, 8 centres have been inspected and 7 centres have been certified. The most common recommendations given by inspectors to assessed centres were the need for documented training, verification of competencies, skills and continuing professional development for all staff members, verification of laboratory and clinical performance indicators and implementation of a quality management system. The inspectors identified some recurring areas of medically assisted reproduction that deviate from good practice: the overuse of ICSI, preimplantation genetic testing for aneuploidies, freeze-all and other add-ons. They often reported that the clinical outcomes could not be objectively assessed because of noninclusion of the started cycles or the frequent use of freeze-all cycles. LIMITATIONS, REASONS FOR CAUTION: No major modifications have been made to the application platform and checklists since the early stages of the certification programme. However, in this short time, quite a few changes in clinical practice have occurred, especially concerning the more frequent use of the 'freeze-all' strategy. As a result, problems arose in the evaluation of clinical outcomes. In addition, because of the COVID-19 pandemic, site visits were substituted by the implementation of virtual visits. While this enabled the certification programme to continue, it is possible that certain critical details that would have been noticed during a traditional site visit may have been overlooked. WIDER IMPLICATIONS OF THE FINDINGS: Regular monitoring of the observations of ARTCC inspectors and analysis of their reports is certainly useful to harmonize inspectors' criteria in the assessment process and to identify chronic deficiencies in clinical and laboratory practice. Non-conformities can be addressed by ESHRE through guidelines and recommendations, as well as through discussion with EU institutions and competent authorities