Publications by authors named "Wyns C"

The ideal morphology of the sperm cell was initially described based on the characteristics of sperm able to migrate through the endocervical canal assuming these had the best fertilization potential. Sperm morphology assessment has moved over the years toward stricter criteria based on the findings from studies that underline its value in successful reproductive outcomes. While treatment options are clear for some conditions related to abnormal sperm morphology, the value of sperm morphology in assisted reproduction requires further investigation.

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  • * Fifty-two fertility specialists reached an agreement on personalizing gonadotropin dosages according to factors like age and BMI, and preferred fresh transfers for low to normal responders while suggesting freeze-all strategies for high responders.
  • * The AMPLITUDE consensus emphasizes the need for optimizing ovarian stimulation protocols in assisted reproductive technology, with recommendations for future research to further enhance treatment outcomes.
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  • The study investigated the current medically assisted reproduction (MAR) data collection systems across EU Member States and explored how they could contribute to a unified registry for the EuMAR project.
  • Significant variations were found in data types, collection methods, and reporting requirements, indicating a need for standardized practices to improve MAR data collection across the EU.
  • The cross-sectional study surveyed and interviewed participants from 26 EU countries, revealing that half have national MAR registries with cycle-by-cycle data, while others rely on aggregated data or have no registry at all.
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Azoospermia is characterized by the absence of sperm in the ejaculate and is categorized into obstructive azoospermia (OA) and nonobstructive azoospermia (NOA). For men with NOA, testicular sperm extraction (TESE) is the only method to obtain sperm for assisted reproductive technology (ART). Given the rarity of these sperm and the unpredictable success of subsequent retrieval attempts, cryopreservation of microdissection-TESE-obtained sperm is essential.

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Study Question: Are Sertoli cells (SCs) from adult Klinefelter men (47,XXY) capable of proliferating in vitro and maintaining their main phenotypical and functional characteristics as do SCs from adult 46,XY patients?

Summary Answer: Isolated SCs from patients with Klinefelter syndrome (KS) can be expanded in vitro while maintaining their characteristics and a stable karyotype, similar to SCs from 46,XY patients.

What Is Known Already: The mechanism leading to testicular tissue degeneration in KS is still unknown. A few recent studies highlight the main role played by SCs in the physiopathology of the disease, but new study models based on co-culture or testicular organoids are needed to further understand the SC's involvement in the mechanism of testicular degeneration and fibrosis, and to find therapeutical targets.

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Study Question: How are ART and IUI regulated, funded, and registered in European countries, and how has the situation changed since 2018?

Summary Answer: Of the 43 countries performing ART and IUI in Europe, and participating in the survey, specific legislation exists in only 39 countries, public funding varies across and sometimes within countries (and is lacking or minimal in four countries), and national registries are in place in 33 countries; only a small number of changes were identified, most of them in the direction of improving accessibility, through increased public financial support and/or opening access to additional subgroups.

What Is Known Already: The annual reports of the European IVF-Monitoring Consortium (EIM) clearly show the existence of different approaches across Europe regarding accessibility to and efficacy of ART and IUI treatments. In a previous survey, some coherent information was gathered about how those techniques were regulated, funded, and registered in European countries, showing that diversity is the paradigm in this medical field.

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In vitro maturation (IVM) is a promising fertility restoration strategy for patients with nonobstructive azoospermia or for prepubertal boys to obtain fertilizing-competent spermatozoa. However, in vitro spermatogenesis is still not achieved with human immature testicular tissue. Knowledge of various human testicular transcriptional profiles from different developmental periods helps us to better understand the testis development.

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Article Synopsis
  • Non-obstructive azoospermia (NOA) is a prevalent and complex issue with varied treatment options and no definitive guidelines, leading to differing management practices internationally.
  • A comprehensive survey with 336 responses from specialists in 49 countries explored current medical and surgical strategies for NOA, analyzing results against existing guidelines and offering expert recommendations.
  • Key findings included diverse approaches to hormonal therapy, significant variation in sperm retrieval success rates, and differing protocols around varicocele repair and follicle-stimulating hormone cutoff levels for sperm retrieval.
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  • * Conducted from July to September 2022, a questionnaire gathered responses from 367 doctors in 49 countries, focusing on how they diagnose NOA through methods like hormone tests and genetic analyses.
  • * The survey identified that while many practices align with guidelines, significant differences in approaches were found, underscoring the need for standardized, evidence-based international guidelines for NOA evaluation.
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Endometriosis is a complex and chronic gynaecological disorder that affects millions of women worldwide, leading to significant morbidity and impacting reproductive health. This condition affects up to 10% of women of reproductive age and is characterised by the presence of endometrial-like tissue outside the uterus, potentially leading to symptoms such as chronic pelvic pain, dysmenorrhoea, dyspareunia, and infertility. The Montreux summit brought a number of experts in this field together to provide a platform for discussion and exchange of ideas.

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Study Question: Twenty years after the inception of the first fertility preservation programme for pre-pubertal boys, what are the current international practices with regard to cryopreservation of immature testicular tissue?

Summary Answer: Worldwide, testicular tissue has been cryopreserved from over 3000 boys under the age of 18 years for a variety of malignant and non-malignant indications; there is variability in practices related to eligibility, clinical assessment, storage, and funding.

What Is Known Already: For male patients receiving gonadotoxic treatment prior to puberty, testicular tissue cryopreservation may provide a method of fertility preservation. While this technique remains experimental, an increasing number of centres worldwide are cryopreserving immature testicular tissue and are approaching clinical application of methods to use this stored tissue to restore fertility.

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Study Question: What is the contamination rate by cancer cells and spermatogonia numbers in immature testicular tissue (ITT) harvested before the start of gonadotoxic therapy in boys with a hematological malignancy?

Summary Answer: Among our cohort of boys diagnosed with acute lymphoblastic leukemia (ALL) and lymphomas, 39% (n = 11/28) had cancer cells identified in their tissues at the time of diagnosis and all patients appeared to have reduced spermatogonia numbers compared to healthy reference cohorts.

What Is Known Already: Young boys affected by a hematological cancer are at risk of contamination of their testes by cancer cells but histological examination is unable to detect the presence of only a few cancer cells, which would preclude autotransplantation of cryobanked ITT for fertility restoration, and more sensitive detection techniques are thus required. Reduced numbers of spermatogonia in ITT in hematological cancer patients have been suggested based on results in a limited number of patients.

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Undifferentiated germ cells, including the spermatogonial stem cell subpopulation required for fertility restoration using human immature testicular tissue (ITT), are difficult to recover as they do not easily adhere to plastics. Due to the scarcity of human ITT for research, we used neonatal porcine ITT. Strategies for maximizing germ cell recovery, including a comparison of two enzymatic digestion protocols (P1 and P2) of ITT fragment sizes (4 mm and 8 mm and multi-step differential plating were explored.

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A mixed-methods study was conducted to investigate sexual function among infertile patients undergoing medically assisted procreation for the first time. The study employed an interview and content analysis approach, involving 45 infertile patients prior to their medically assisted procreation procedures. The findings revealed that infertile patients are a group at risk for sexual distress.

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Study Question: What are the data and trends on ART and IUI cycle numbers and their outcomes, and on fertility preservation (FP) interventions, reported in 2019 as compared to previous years?

Summary Answer: The 23rd ESHRE report highlights the rising ART treatment cycles and children born, alongside a decline in twin deliveries owing to decreasing multiple embryo transfers; fresh IVF or ICSI cycles exhibited higher delivery rates, whereas frozen embryo transfers (FET) showed higher pregnancy rates (PRs), and reported IUI cycles decreased while maintaining stable outcomes.

What Is Known Already: ART aggregated data generated by national registries, clinics, or professional societies have been gathered and analyzed by the European IVF-Monitoring (EIM) Consortium since 1997 and reported in a total of 22 manuscripts published in Human Reproduction and Human Reproduction Open.

Study Design, Size, Duration: Data on medically assisted reproduction (MAR) from European countries are collected by EIM for ESHRE each year.

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Article Synopsis
  • The study investigates global practices and challenges in using sperm DNA fragmentation (SDF) assays, which can affect male reproductive potential, as outlined in the latest WHO manual.
  • A survey of 436 reproductive clinicians revealed that the most popular SDF assay is TUNEL, with a significant influence from availability on their choices.
  • Clinicians see the value of SDF testing in understanding infertility but face barriers like insufficient professional guidelines and a lack of accepted reference values for interpreting SDF results.
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Acquired disorders and congenital defects of the male and female reproductive systems can have profound impacts on patients, causing sexual and endocrine dysfunction and infertility, as well as psychosocial consequences that affect their self-esteem, identity, sexuality, and relationships. Reproductive tissue engineering (REPROTEN) is a promising approach to restore fertility and improve the quality of life of patients with reproductive disorders by developing, replacing, or regenerating cells, tissues, and organs from the reproductive and urinary systems. In this review, we explore the latest advancements in REPROTEN techniques and their applications for addressing degenerative conditions in male and female reproductive organs.

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Article Synopsis
  • The study investigates global practices for managing sperm DNA fragmentation (SDF) in infertile men, highlighting its impact on fertility and assisted reproductive technology (ART).
  • A survey collecting data from 436 reproductive experts across 55 countries revealed a common recommendation for lifestyle changes and antioxidants, with varying durations for treatment and differing management approaches for specific infertility cases.
  • The findings indicate a lack of uniformity in practices, emphasizing the need for standardized guidelines and expert consensus for treating men with elevated SDF.
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  • The study explores global practices for sperm DNA fragmentation (SDF) testing in infertile men, following its inclusion in the WHO laboratory manual.
  • A survey conducted among 436 infertility clinicians across 55 countries reveals varied testing practices, with many testing SDF in cases of unexplained infertility, recurrent pregnancy loss, and among smokers.
  • The findings highlight the need for clearer professional guidelines on SDF testing, given the diversity in current practices and the potential benefits for certain patient populations.
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More than 20 years ago, the survey of activities in medically assisted reproduction (MAR) was initiated in Europe and resulted in cross-sectional annual reports, as issued by the European IVF Monitoring (EIM) consortium of ESHRE. Over time, these reports mirror the continuous development of the technologies and contribute to increased transparency and surveillance of reproductive care. Meanwhile, progressive changes of existing treatment modalities and the introduction of new technologies resulted in the need of a cumulative approach in the assessment of treatment outcomes, which warrants a prospective cycle-by-cycle data registry on MAR activities, including fertility preservation.

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For more than two decades, the European IVF-Monitoring Consortium has collected data on IVF in Europe with the aim of monitoring the quality and safety of assisted reproductive technology (ART) treatments, to ensure the highest performance with the lowest risk for patients and their offspring. Likewise, the Society for Assisted Reproductive Technology in the USA and the Australia/New Zealand Assisted Reproduction Database collect, process and publish data in their regions. The better the legal framework for ART surveillance, the more complete and reliable are the datasets.

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Fertility restoration in patients that survived a hematological cancer during childhood is a core part of their care pathway. Nonetheless, there might be a risk of contamination of the gonads by cancer cells, especially in patients presenting with leukemia and lymphoma. When only a few cancer cells have reached the gonad, they may not be detected by routine histological examination, and therefore more sensitive techniques are required before being confident of the safety of transplanting cryostored testicular and ovarian tissues or cells back to the patient after recovery.

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Research Question: What is the discontinuation rate among patients with remaining cryopreserved embryos in Belgium and what are the reasons for discontinuation?

Design: Multicentre, cross-sectional study across 11 Belgian fertility clinics. Patients were eligible (n = 1917) if they had previously undergone an unsuccessful fresh embryo transfer (fresh group) or frozen embryo transfer (FET) (in-between group) and did not start a subsequent FET cycle within 1 year despite having remaining cryopreserved embryos. The denominator was all patients with embryos cryopreserved during the same period (2012-2017) (n = 21,329).

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Study Question: What are the data and trends on ART and IUI cycle numbers and their outcomes, and on fertility preservation (FP) interventions, reported in 2018 as compared to previous years?

Summary Answer: The 22nd ESHRE report shows a continued increase in reported numbers of ART treatment cycles and children born in Europe, a decrease in transfers with more than one embryo with a further reduction of twin delivery rates (DRs) as compared to 2017, higher DRs per transfer after fresh IVF or ICSI cycles (without considering freeze-all cycles) than after frozen embryo transfer (FET) with higher pregnancy rates (PRs) after FET and the number of reported IUI cycles decreased while their PR and DR remained stable.

What Is Known Already: ART aggregated data generated by national registries, clinics or professional societies have been gathered and analysed by the European IVF-monitoring Consortium (EIM) since 1997 and reported in 21 manuscripts published in and

Study Design Size Duration: Data on medically assisted reproduction (MAR) from European countries are collected by EIM for ESHRE on a yearly basis. The data on treatment cycles performed between 1 January and 31 December 2018 were provided by either national registries or registries based on initiatives of medical associations and scientific organizations or committed persons of 39 countries.

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maturation of immature testicular tissue (ITT) cryopreserved for fertility preservation is a promising fertility restoration strategy. Organotypic tissue culture proved successful in mice, leading to live births. In larger mammals, including humans, efficiently reproducing spermatogenesis remains challenging.

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