Publications by authors named "Michel de Vos"

Purpose: This survey aimed to assess the public's knowledge and opinions on oocyte donation (OD) among a large, unselected cohort of young Belgian women, and to explore aspects that could be enhanced to promote future OD programs.

Methods: We conducted a quantitative, epidemiological, cross-sectional web-based survey from February 2023 to April 2023. A private questionnaire was distributed to young women (21-30 years) living in Belgium via a digital link.

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Summary: Delayed puberty in girls is often related to late maturation but is occasionally the first sign of premature ovarian insufficiency (POI). POI is a condition that affects ovarian function and fertility, and its etiology is unknown in most cases. Genetic factors have recently been identified in 20-25% of women with POI, involving genes that regulate various aspects of ovarian development and maintenance.

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Article Synopsis
  • * Involving 430 women across 860 cycles, the research compares outcomes from a standard stimulation cycle versus one that included early GnRH antagonist pretreatment.
  • * Results indicate that the pretreatment significantly increases the total number of retrieved COCs and mature oocytes, suggesting benefits for fertility treatment protocols.
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  • - The European Society of Gynaecological Oncology, alongside other societies, created evidence-based guidelines for fertility-sparing strategies in patients with cervical and ovarian cancers, as well as borderline ovarian tumors.
  • - These guidelines were developed through a thorough literature review and involved a diverse group of 25 experts in multiple medical fields, ensuring a comprehensive approach.
  • - Prior to release, the guidelines were vetted by 121 independent cancer care professionals and patient representatives, addressing key aspects of initial management, fertility optimization, and future pregnancy desires.
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Purpose: In this survey, we aimed to provide the description of previous oocyte donors' profile in a Belgian tertiary fertility hospital clinic. The research question is as follows: could certain aspects be changed or improved, according to previous oocyte donors? The final purpose is to boost adherence to future oocyte donation (OD) programs, given the large gap between supply and demand.

Methods: We set up an observational cross-sectional study of oocyte donors who were recruited in a tertiary referral hospital.

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Objective: To demonstrate clinical techniques for in vitro maturation (IVM) treatment, including stimulation recommendations, small follicle pick-up procedures, and compact cumulus-oocyte complex (COC) search practice.

Design: This video utilizes live-action footage from surgery and embryology practice for a representative IVM treatment cycle, with step-by-step instructions and recommendations for practice procedures.

Setting: In vitro fertilization (IVF) clinic.

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Mature oocyte vitrification is the standard of care to preserve fertility in women at risk of infertility. However, ovarian tissue cryopreservation (OTC) is still the only option to preserve fertility in women who need to start gonadotoxic treatment urgently or in prepubertal children. During ovarian cortex preparation for cryopreservation, medullar tissue is removed.

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  • The study looked at whether starting hormone treatment later than usual could still give the same number of eggs for egg donors.
  • Two groups were tested: one starting early and one starting late, with 84 women in total.
  • Results showed that both groups produced about the same number of eggs, but the early group used fewer hormones, took less time, and cost more money for medication.
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Purpose: Our objective is to predict the cumulative live birth rate (CLBR) and identify the specific subset within the population undergoing preimplantation genetic testing for monogenic disorders (PGT-M) and chromosomal structural rearrangements (PGT-SR) which is likely to exhibit a diminished expected CLBR based on various patient demographics.

Methods: We performed a single-centre retrospective cohort study including 1522 women undergoing 3130 PGT cycles at a referral centre for PGT. A logistic regression analysis was performed to predict the CLBR per ovarian stimulation in women undergoing PGT-M by polymerase chain reaction (PCR) or single-nucleotide polymorphism (SNP) array, and in women undergoing PGT-SR by SNP array, array comparative genomic hybridization (CGH) or next-generation sequencing (NGS).

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Fertility preservation is currently offered to young women with breast cancer to increase their chances of motherhood after a potentially gonadotoxic treatment. Ovarian stimulation with oocyte vitrification and cryopreservation of ovarian tissue remain the most commonly used methods of choice. Whichever method is preferred is very much dependent on the practice and experience of the clinics, although for breast cancer in particular one method might be superior to the other.

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Purpose: In the past decades, a positive attitude towards having children has been reported in young people. The current generation of adolescents is increasingly concerned about environmental cataclysm which may have an impact on their desire for children. The purpose of this study is to depict the current attitudes in Flemish adolescents towards having children.

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Research Question: Can a strategy for scoring oocyte quality, based on cumulus cell (CC) gene expression, prioritize oocytes with the highest implantation potential, while limiting the number of embryos to be processed in culture and the number of supernumerary embryos to be vitrified?

Design: An interventional, blinded, prospective cohort study was retrospectively analyzed. In the original study, patients underwent a fresh Day3 single embryo transfer with embryos ranked based on morphology and CC gene expression (Aurora Test). The additional ranking of the embryos with the Aurora Test resulted in significant higher clinical pregnancy and live birth rates.

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  • The study investigates the global DNA methylation differences in neonates conceived through two methods: capacitation-IVM (CAPA-IVM) and conventional IVF.
  • Biological samples from both groups were collected at delivery, primarily focusing on placental tissue, cord blood, and buccal smears, analyzed for methylation using advanced techniques.
  • Results indicate that while there were no significant differences in neonatal buccal smears, CAPA-IVM was linked to specific changes in DNA methylation patterns in placental tissue and showed variability in cord blood compared to conventional IVF, but without changes in gene expression.
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Premature ovarian insufficiency (POI) is a rare cause of primary amenorrhea in adolescents. For young women with uncertain etiology of POI, genetic and autoimmune testing may be recommended to assist in treatment and management decisions. This report presents a case of POI in a 16-year-old adolescent with both poly-autoimmune disease and a heterozygous missense variant in the bone morphogenic factor 15 () gene, both potentially involved in the pathogenesis of POI.

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Article Synopsis
  • Recent advancements in in vitro maturation (IVM) of oocytes, particularly through biphasic IVM, show promise for improving assisted reproductive technologies (ART) by allowing collection of immature oocytes from minimally stimulated patients and incorporating a preparatory culture phase.
  • The review aims to highlight significant scientific discoveries in ovarian biology and detail the new pre-IVM methodologies, alongside assessing outcomes from both animal studies and clinical trials in humans.
  • By reducing the reliance on gonadotrophins and utilizing developing oocytes from small antral follicles, biphasic IVM could potentially enhance the safety and efficiency of fertility treatments.
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Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present.

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Although a wealth of data has been published regarding fertility preservation (FP) in women with malignant diseases who receive gonadotoxic treatment, the role of FP in non-malignant conditions has been studied to a much lesser extent. These include benign haematological, autoimmune, and genetic disorders, as well as a multitude of benign gynaecological conditions (BGCs) that may compromise ovarian reserve and/or reproductive potential due to pathogenic mechanisms or as a result of medical or surgical treatments. Alongside accumulating data that document the reproductive potential of cryopreserved oocytes and ovarian tissue, there is potential interest in FP for women with BGCs at risk of infertility; however, there are currently insufficient data about FP in women with BGCs to develop guidelines for clinical practice.

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Research Question: Does additional supplementation with oral dydrogesterone improve reproductive outcomes in patients with low serum progesterone concentrations on the day of frozen embryo transfer (FET) after artificial (HRT) endometrial preparation?

Design: Retrospective, single-centre cohort study including 694 unique patients performing single blastocyst transfer in an HRT cycle. For luteal phase support, intravaginal micronized vaginal progesterone (MVP, 400 mg twice daily) was administered. Serum progesterone concentrations were assessed prior to FET and outco-mes were compared among patients with normal serum progesterone (≥8.

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Oocyte in vitro maturation (IVM) has been proposed as an alternative to conventional ovarian stimulation (COS) in subfertile women with polycystic ovary syndrome. To evaluate the effectiveness and safety of IVM compared with COS in women with predicted hyperresponse to gonadotropins, we searched the published literature for relevant studies comparing any IVM protocol with any COS protocol followed by in vitro fertilization or intracytoplasmic sperm injection. A systematic review was undertaken on 3 eligible prospective studies.

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Background And Aims: Inflammatory bowel disease (IBD) can affect patients during their childbearing years. Literature evidence is scarce regarding the level of knowledge among health care professionals (HCPs) and patients about the impact of IBD on fertility. The aim of this survey was to investigate HCPs' and patients' knowledge on fertility, pregnancy, and sexual function, to evaluate how HCPs approach this topic and to report patients' reproductive outcomes.

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Background And Aim: In view of their frequent onset during childbearing years, the impact of inflammatory bowel diseases [IBD] on reproductive health is of important concern to young women and to the IBD physician. This study aims to assess the fertility and assisted reproductive technologies outcomes in non-surgically treated IBD females.

Methods: A systematic review was conducted using MEDLINE, SCOPUS, and EMBASE [until March 2022] to identify studies assessing fertility and assisted reproductive technologies outcomes in women with non-operated IBD, compared with non-IBD patients.

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Oocyte vitrification, also known as egg freezing, is increasingly being used by women as a precautionary measure against the anticipated decline in fertility. In countries where this procedure is allowed, elective oocyte vitrification has become an integral part of the treatment portfolio of fertility clinics. The widespread tendency towards the postponement of motherhood and the advances in laboratory technologies are encouraging women to consider oocyte vitrification and, by doing so, increase their reproductive autonomy.

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Research Question: What is the association between the development of pre-eclampsia and endometrial preparation prior to vitrified-warmed embryo transfer (frozen embryo transfer, FET)?

Design: A retrospective cohort study at a tertiary university-based hospital, including a total of 536 pregnant patients who underwent a FET between 2010 and 2019 and delivered in the same institution; 325 patients underwent natural cycle FET (NC-FET) and 211 artificial cycle FET (AC-FET).

Results: Unadjusted, the incidence of pre-eclampsia was significantly higher in AC-FET cycles than in NC-FET cycles (3.7% versus 11.

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Article Synopsis
  • * Sixteen patients were analyzed, and all samples tested negative for SARS-CoV-2 RNA, with no inflammatory issues found in the endometrial tissue; this suggests that the virus may not impact fertility in these cases.
  • * The findings indicate no viral RNA was detected, but caution is advised due to the small sample size, and further research is needed regarding potential risks to embryos during ART procedures in SARS-CoV-2-positive women.
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