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Hum. Reprod. Update [JOURNAL]

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Prevalence of PCOS and related hyperandrogenic traits in premenopausal women with type 1 diabetes: a systematic review and meta-analysis.

Bayona A, Martínez-Vaello V, Zamora J … +3 more , Nattero-Chávez L, Luque-Ramírez M, Escobar-Morreale HF

Hum Reprod Update · 2022 Jun · PMID 35237802 · Publisher ↗

BACKGROUND: An increased prevalence of functional hyperandrogenism-including polycystic ovary syndrome (PCOS)-has been described in women with type 1 diabetes (T1D). However, heterogeneity between studies is frequent, an... BACKGROUND: An increased prevalence of functional hyperandrogenism-including polycystic ovary syndrome (PCOS)-has been described in women with type 1 diabetes (T1D). However, heterogeneity between studies is frequent, and prevalence rates vary according to different criteria used for the diagnosis of PCOS and the population studied. OBJECTIVE AND RATIONALE: We aimed to perform a systematic review and meta-analysis of the prevalence of PCOS and related hyperandrogenic traits in premenopausal women with T1D. This way, we intend to increase the precision of the estimates of prevalence of PCOS and related traits in women with T1D, and to explore sources of heterogeneity while providing prevalence estimates for clinically relevant subgroups such as the different phenotypes. SEARCH METHODS: We conducted a systematic review of the literature using Medline-OVID and Embase databases (Open Science Framework registry for systematic review protocols, https://osf.io/6cv9p/). Studies published up to 29 March 2021 were considered. We selected cross-sectional or prospective studies that reported, in patients with T1D, prevalence data on PCOS according to current definitions and different phenotypes, and/or prevalence rates of other related traits (hirsutism, hyperandrogenaemia, oligo-amenorrhoea and/or polycystic ovarian morphology: PCOM). Exclusion criteria for the review were studies addressing types of diabetes other than T1D; and studies using diagnostic definitions of PCOS different than those mentioned above. Two independent researchers performed data extraction. To assess the risk of bias, we used a tool developed specifically to appraise population-based prevalence studies. OUTCOMES: We selected 19 studies (1042 women) reporting the prevalence of PCOS and/or other hyperandrogenic traits. Regarding bias, 12 studies were considered of low-risk, and the remaining seven studies were considered intermediate risk. The pooled prevalence of PCOS when considering all possible phenotypes (ESHRE- American Society for Reproductive Medicine criteria) in T1D was 26% (95% CI: 19-34%; 13 studies, 684 women). Pooled prevalence of classic PCOS (US National Institutes of Health criteria) was 16% (95% CI: 10-22%; 9 studies, 614 women). Pooled prevalence of hyperandrogenic PCOS (Androgen Excess and PCOS Society criteria) was 26% (95% CI: 16-41%; 5 studies, 329 women). Hirsutism (24%), hyperandrogenaemia (29%), oligomenorrhoea (24%) and PCOM (34%) were also prevalent. Heterogeneity was high in almost all these meta-analyses. WIDER IMPLICATIONS: This systematic review and meta-analysis showed that PCOS and related hyperandrogenic traits are present in approximately one in every four women with T1D. Larger studies are needed to confirm this association, to address the effect of different variables on the occurrence of PCOS.

HLA Class Ib-receptor interactions during embryo implantation and early pregnancy.

Nilsson LL, Hviid TVF

Hum Reprod Update · 2022 May · PMID 35234898 · Publisher ↗

BACKGROUND: Although the immune system intuitively must have an important role in embryo implantation and in the achievement of a pregnancy, the molecular details have for long been controversial. The role of the human l... BACKGROUND: Although the immune system intuitively must have an important role in embryo implantation and in the achievement of a pregnancy, the molecular details have for long been controversial. The role of the human leukocyte antigen (HLA) system has been debated. The unique HLA expression profile of the HLA Class Ia molecule HLA-C and the HLA Class Ib molecules HLA-E, HLA-F and HLA-G at the feto-maternal interface is now recognized. However, HLA Class Ib molecules may also have a role in embryo implantation and pregnancy success. OBJECTIVE AND RATIONALE: The aim of this review was to evaluate the literature and recent discoveries on the role of the non-polymorphic HLA Class Ib molecules with a focus on HLA-F and HLA-G molecules at the time of implantation, including the interaction with uterine immune cells through the specific receptors immunoglobulin-like transcript 2 (ILT2), ILT4 and a number of killer cell immunoglobulin-like receptors (KIRs), and the importance of HLA-F and HLA-G genetic variation that influences fertility and time-to-pregnancy. SEARCH METHODS: Drawing on recent advances in basic and clinical studies, we performed a narrative review of the scientific literature to provide a timely update on the role of HLA Class Ib in embryo implantation, fertility and infertility. Pertinent studies were searched in PubMed/Medline using relevant key words. OUTCOMES: Both HLA-F and HLA-G interact with inhibitory or activating ILT2 or ILT4 receptors and KIRs on uterine immune cells, especially uterine natural killer (NK) cells that are highly abundant in the mid-secretory endometrium and in early pregnancy. The binding of HLA-G to ILT2 stimulates the secretion of growth-promoting factors from decidual NK cells. However, functional aspects of a HLA-F-receptor interaction remain to be clarified. Recent studies indicate that HLA-F and HLA-G are expressed in mid-secretory endometrium and HLA-G is expressed in the blastocyst. HLA-F fluctuates during the menstrual cycle with high levels during the implantation window. The level of HLA-F protein expression correlates with the number of CD56-positive NK cells in the mid-secretory endometrium. HLA-F and HLA-G gene polymorphisms, including a single nucleotide polymorphism (SNP) in a progesterone-responsive element, are associated with time-to-pregnancy. Depending on the SNP genotype, the effect of progesterone varies resulting in differences in HLA-F expression and thereby the interaction with receptors on the uterine NK cells. Studies suggest that the expression of HLA-G and HLA-F, both by the embryonic-derived trophoblast cells and by cells in the endometrium and decidua, and the interaction between HLA-G and HLA-F with specific receptors on uterine immune cells, stimulate and facilitate embryo implantation and placentation by secretion of growth factors, cytokines and angiogenic factors. WIDER IMPLICATIONS: A detailed understanding of the molecular mechanisms controlling the expression of HLA-F and HLA-G periconceptionally and in early pregnancy may improve the success of ART and holds promise for further insight into pathophysiological aspects of certain pregnancy complications.

Fresh and cryopreserved ovarian tissue transplantation for preserving reproductive and endocrine function: a systematic review and individual patient data meta-analysis.

Khattak H, Malhas R, Craciunas L … +17 more , Afifi Y, Amorim CA, Fishel S, Silber S, Gook D, Demeestere I, Bystrova O, Lisyanskaya A, Manikhas G, Lotz L, Dittrich R, Colmorn LB, Macklon KT, Hjorth IMD, Kristensen SG, Gallos I, Coomarasamy A

Hum Reprod Update · 2022 May · PMID 35199164 · Full text

BACKGROUND: Ovarian tissue cryopreservation involves freezing and storing of surgically retrieved ovarian tissue in liquid or vapour nitrogen below -190°C. The tissue can be thawed and transplanted back with the aim of r... BACKGROUND: Ovarian tissue cryopreservation involves freezing and storing of surgically retrieved ovarian tissue in liquid or vapour nitrogen below -190°C. The tissue can be thawed and transplanted back with the aim of restoring fertility or ovarian endocrine function. The techniques for human ovarian tissue freezing and transplantation have evolved over the last 20 years, particularly in the context of fertility preservation in pre-pubertal cancer patients. Fresh ovarian tissue transplantation, using an autograft or donor tissue, is a more recent development; it has the potential to preserve fertility and hormonal function in women who have their ovaries removed for benign gynaecological conditions. The techniques of ovarian tissue cryopreservation and transplantation have progressed rapidly since inception; however, the evidence on the success of this intervention is largely based on case reports and case series. OBJECTIVE AND RATIONALE: The aim of this study was to systematically review the current evidence by incorporating study-level and individual patient-level meta-analyses of women who received ovarian transplants, including frozen-thawed transplant, fresh or donor graft. SEARCH METHODS: The review protocol was registered with PROSPERO (CRD42018115233). A comprehensive literature search was performed using MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials from database inception to October 2020. Authors were also contacted for individual patient data if relevant outcomes were not reported in the published manuscripts. Meta-analysis was performed using inverse-variance weighting to calculate summary estimates using a fixed-effects model. OUTCOMES: The review included 87 studies (735 women). Twenty studies reported on ≥5 cases of ovarian transplants and were included in the meta-analysis (568 women). Fertility outcomes included pregnancy, live birth and miscarriage rates, and endocrine outcomes included oestrogen, FSH and LH levels. The pooled rates were 37% (95% CI: 32-43%) for pregnancy, 28% (95% CI: 24-34%) for live birth and 37% (95% CI: 30-46%) for miscarriage following frozen ovarian tissue transplantation. Pooled mean for pre-transplant oestrogen was 101.6 pmol/l (95% CI: 47.9-155.3), which increased post-transplant to 522.4 pmol/l (95% CI: 315.4-729; mean difference: 228.24; 95% CI: 180.5-276). Pooled mean of pre-transplant FSH was 66.4 IU/l (95% CI: 52.8-84), which decreased post-transplant to 14.1 IU/l (95% CI: 10.9-17.3; mean difference 61.8; 95% CI: 57-66.6). The median time to return of FSH to a value <25 IU/l was 19 weeks (interquartile range: 15-26 weeks; range: 0.4-208 weeks). The median duration of graft function was 2.5 years (interquartile range: 1.4-3.4 years; range: 0.7-5 years). The analysis demonstrated that ovarian tissue cryopreservation and transplantation could restore reproductive and hormonal functions in women. Further studies with larger samples of well-characterized populations are required to define the optimal retrieval, cryopreservation and transplantation processes. WIDER IMPLICATIONS: Ovarian tissue cryopreservation and transplantation may not only be effective in restoring fertility but also the return of reproductive endocrine function. Although this technology was developed as a fertility preservation option, it may have the scope to be considered for endocrine function preservation.

Anti-Müllerian hormone as a marker of ovarian reserve and premature ovarian insufficiency in children and women with cancer: a systematic review.

Anderson RA, Cameron D, Clatot F … +4 more , Demeestere I, Lambertini M, Nelson SM, Peccatori F

Hum Reprod Update · 2022 May · PMID 35199161 · Full text

BACKGROUND: Female patients undergoing anticancer treatment are at elevated risk of adverse ovarian outcomes including infertility and premature ovarian insufficiency (POI), which is associated with short- and long-term... BACKGROUND: Female patients undergoing anticancer treatment are at elevated risk of adverse ovarian outcomes including infertility and premature ovarian insufficiency (POI), which is associated with short- and long-term health risks. Anti-Müllerian hormone (AMH) is a key biomarker of ovarian reserve, but its role prior to and after cancer treatment is less well understood. OBJECTIVE AND RATIONALE: To conduct a systematic review evaluating AMH as a biomarker of ovarian reserve and POI before and after anticancer treatment, which has become a pressing clinical issue in reproductive medicine. There are a large number of observational studies, but differences in patient groups, cancer diagnoses and study design make this a confusing field that will benefit from a thorough and robust review. SEARCH METHODS: A systematic literature search for AMH in women with cancer was conducted in PubMed, Embase and Cochrane Central Register of Controlled Trials up to 1 April 2021. Bias review was conducted using the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) protocol along with qualitative assessment of quality. Exploratory subgroups were established based on age, cancer type and length of follow-up. OUTCOMES: Ninety-two publications (N = 9183 patients) were included in this analysis after quality and bias review. Reduced/undetectable AMH was consistently identified in 69/75 studies (92%) following chemotherapy or radiotherapy, with reductions ranging from 42% to concentrations below the limit of detection, and many reporting mean or median declines of ≥90%. Where longitudinal data were analysed (42 studies), a majority (33/42 (79%)) of studies reported at least partial recovery of AMH at follow-up, however, effect estimates were highly variable, reflecting that AMH levels were strongly impacted by anticancer treatment (i.e. the chemotherapy regimen used and the number of treatment cycles need), with recovery and its degree determined by treatment regimen, age and pre-treatment AMH level. In 16/31 (52%) publications, oligo/amenorrhoea was associated with lower post-treatment AMH consistent with impending POI, although menstruation and/or pregnancy were reported in patients with low or undetectable AMH. Long-term (>5 years) follow-up of paediatric patients following cancer treatment also found significantly lower AMH compared with control groups in 14/20 (70%) of studies, with very variable effect sizes from complete loss of AMH to full recovery depending on treatment exposure, as in adult patients. WIDER IMPLICATIONS: AMH can be used to identify the damaging effect of cancer treatments on ovarian function. This can be applied to individual women, including pre-pubertal and adolescent girls, as well as comparing different treatment regimens, ages and pre-treatment AMH levels in populations of women. While there was evidence for its value in the diagnosis of POI after cancer treatment, further studies across a range of diagnoses/treatment regimens and patient ages are required to clarify this, and to quantify its predictive value. A major limitation for the use of AMH clinically is the very limited data relating post-treatment AMH levels to fertility, duration of reproductive lifespan or time to POI; analysis of these clinically relevant outcomes will be important in further research.

Epigenomic and enhancer dysregulation in uterine leiomyomas.

Mlodawska OW, Saini P, Parker JB … +4 more , Wei JJ, Bulun SE, Simon MA, Chakravarti D

Hum Reprod Update · 2022 Jun · PMID 35199155 · Full text

BACKGROUND: Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prev... BACKGROUND: Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prevalence of this tumor in women by the age of 50 years. Black women are particularly affected, with an increased incidence, earlier age of onset, larger and faster growing fibroids and greater severity of symptoms as compared to White women. Although advances in identifying genetic and environmental factors to delineate these fibroids have already been made, only recently has the role of epigenomics in the pathogenesis of this disease been considered. OBJECTIVE AND RATIONALE: Over recent years, studies have identified multiple epigenomic aberrations that may contribute to leiomyoma development and growth. This review will focus on the most recent discoveries in three categories of epigenomic changes found in uterine fibroids, namely aberrant DNA methylation, histone tail modifications and histone variant exchange, and their translation into altered target gene architecture and transcriptional outcome. The findings demonstrating how the altered 3D shape of the enhancer can regulate gene expression from millions of base pairs away will be discussed. Additionally, translational implications of these discoveries and potential roadblocks in leiomyoma treatment will be addressed. SEARCH METHODS: A comprehensive PubMed search was performed to identify published articles containing keywords relevant to the focus of the review, such as: uterine leiomyoma, uterine fibroids, epigenetic alterations, epigenomics, stem cells, chromatin modifications, extracellular matrix [ECM] organization, DNA methylation, enhancer, histone post-translational modifications and dysregulated gene expression. Articles until September 2021 were explored and evaluated to identify relevant updates in the field. Most of the articles focused on in the discussion were published between 2015 and 2021, although some key discoveries made before 2015 were included for background information and foundational purposes. We apologize to the authors whose work was not included because of space restrictions or inadvertent omission. OUTCOMES: Chemical alterations to the DNA structure and of nucleosomal histones, without changing the underlying DNA sequence, have now been implicated in the phenotypic manifestation of uterine leiomyomas. Genome-wide DNA methylation analysis has revealed subsets of either suppressed or overexpressed genes accompanied by aberrant promoter methylation. Furthermore, differential promoter access resulting from altered 3D chromatin structure and histone modifications plays a role in regulating transcription of key genes thought to be involved in leiomyoma etiology. The dysregulated genes function in tumor suppression, apoptosis, angiogenesis, ECM formation, a variety of cancer-related signaling pathways and stem cell differentiation. Aberrant DNA methylation or histone modification is also observed in altering enhancer architecture, which leads to changes in enhancer-promoter contact strength, producing novel explanations for the overexpression of high mobility group AT-hook 2 and gene dysregulation found in mediator complex subunit 12 mutant fibroids. While many molecular mechanisms and epigenomic features have been investigated, the basis for the racial disparity observed among those in the Black population remains unclear. WIDER IMPLICATIONS: A comprehensive understanding of the exact pathogenesis of uterine leiomyoma is lacking and requires attention as it can provide clues for prevention and viable non-surgical treatment. These findings will widen our knowledge of the role epigenomics plays in the mechanisms related to uterine leiomyoma development and highlight novel approaches for the prevention and identification of epigenome targets for long-term non-invasive treatment options of this significantly common disease.

Early programming of reproductive health and fertility: novel neuroendocrine mechanisms and implications in reproductive medicine.

Sánchez-Garrido MA, García-Galiano D, Tena-Sempere M

Hum Reprod Update · 2022 May · PMID 35187579 · Full text

BACKGROUND: According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurre... BACKGROUND: According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurrence of diverse pathologies later in life. Indeed, adverse conditions during these critical developmental windows of high plasticity have been reported to alter the offspring developmental trajectory, causing permanent functional and structural perturbations that in the long term may enhance disease susceptibility. However, while solid evidence has documented that fluctuations in environmental factors, ranging from nutrient availability to chemicals, in early developmental stages (including the peri-conceptional period) have discernible programming effects that increase vulnerability to develop metabolic perturbations, the impact and eventual mechanisms involved, of such developmental alterations on the reproductive phenotype of offspring have received less attention. OBJECTIVE AND RATIONALE: This review will summarize recent advances in basic and clinical research that support the concept of DOHaD in the context of the impact of nutritional and hormonal perturbations, occurring during the periconceptional, fetal and early postnatal stages, on different aspects of reproductive function in both sexes. Special emphasis will be given to the effects of early nutritional stress on the timing of puberty and adult gonadotropic function, and to address the underlying neuroendocrine pathways, with particular attention to involvement of the Kiss1 system in these reproductive perturbations. The implications of such phenomena in terms of reproductive medicine will also be considered. SEARCH METHODS: A comprehensive MEDLINE search, using PubMed as main interface, of research articles and reviews, published mainly between 2006 and 2021, has been carried out. Search was implemented using multiple terms, focusing on clinical and preclinical data from DOHaD studies, addressing periconceptional, gestational and perinatal programming of reproduction. Selected studies addressing early programming of metabolic function have also been considered, when relevant. OUTCOMES: A solid body of evidence, from clinical and preclinical studies, has documented the impact of nutritional and hormonal fluctuations during the periconceptional, prenatal and early postnatal periods on pubertal maturation, as well as adult gonadotropic function and fertility. Furthermore, exposure to environmental chemicals, such as bisphenol A, and maternal stress has been shown to negatively influence pubertal development and gonadotropic function in adulthood. The underlying neuroendocrine pathways and mechanisms involved have been also addressed, mainly by preclinical studies, which have identified an, as yet incomplete, array of molecular and neurohormonal effectors. These include, prominently, epigenetic regulatory mechanisms and the hypothalamic Kiss1 system, which likely contribute to the generation of reproductive alterations in conditions of early nutritional and/or metabolic stress. In addition to the Kiss1 system, other major hypothalamic regulators of GnRH neurosecretion, such as γ-aminobutyric acid and glutamate, may be targets of developmental programming. WIDER IMPLICATIONS: This review addresses an underdeveloped area of reproductive biology and medicine that may help to improve our understanding of human reproductive disorders and stresses the importance, and eventual pathogenic impact, of early determinants of puberty, adult reproductive function and fertility.

Evaluating interventions and adjuncts to optimize pregnancy outcomes in subfertile women: an overview review.

Holt-Kentwell A, Ghosh J, Devall A … +2 more , Coomarasamy A, Dhillon-Smith RK

Hum Reprod Update · 2022 Jun · PMID 35137098 · Publisher ↗

BACKGROUND: There is a wealth of information regarding interventions for treating subfertility. The majority of studies exploring interventions for improving conception rates also report on pregnancy outcomes. However, t... BACKGROUND: There is a wealth of information regarding interventions for treating subfertility. The majority of studies exploring interventions for improving conception rates also report on pregnancy outcomes. However, there is no efficient way for clinicians, researchers, funding organizations, decision-making bodies or women themselves to easily access and review the evidence for the effect of adjuvant therapies on key pregnancy outcomes in subfertile women. OBJECTIVE AND RATIONALE: The aim was to summarize all published systematic reviews (SRs) of randomized controlled trials (RCTs) of interventions in the subfertile population, specifically reporting on the pregnancy outcomes of miscarriage and live birth. Furthermore, we aimed to highlight promising interventions and areas that need high-quality evidence. SEARCH METHODS: We searched the Cochrane Database of Systematic Reviews and PubMed clinical queries SR filter (inception until July 2021) with a list of key words to capture all SRs specifying or reporting any miscarriage outcome. Studies were included if they were SRs of RCTs. The population was subfertile women (pregnant or trying to conceive) and any intervention (versus placebo or no treatment) was included. We adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) for determining the quality of the evidence. Exclusion criteria were overview reviews, reviews that exclusively reported on women conceiving via natural conception, reviews including non-randomized study designs or reviews where miscarriage or live birth outcomes were not specified or reported. OUTCOMES: The primary outcome was miscarriage, defined as pregnancy loss <24 weeks of gestation. Data were also extracted for live birth where available. We included 75 published SRs containing 121 251 participants. There were 14 classes of intervention identified: luteal phase, immunotherapy, anticoagulants, hCG, micronutrients, lifestyle, endocrine, surgical, pre-implantation genetic testing for aneuploidies (PGT-As), laboratory techniques, endometrial injury, ART protocols, other adjuncts/techniques in the ART process and complementary interventions. The interventions with at least moderate-quality evidence of benefit in reducing risk of miscarriage or improving the chance of a live birth are: intrauterine hCG at time of cleavage stage embryo transfer, but not blastocyst transfer, antioxidant therapy in males, dehydroepiandrosterone in women and embryo medium containing high hyaluronic acid. Interventions showing potential increased risk of miscarriage or reduced live birth rate are: embryo culture supernatant injection before embryo transfer in frozen cycles and PGT-A with the use of fluorescence in situ hybridization. WIDER IMPLICATIONS: This review provides an overview of key pregnancy outcomes from published SRs of RCTs in subfertile women. It provides access to concisely summarized information and will help clinicians and policy makers identify knowledge gaps in the field, whilst covering a broad range of topics, to help improve pregnancy outcomes for subfertile couples. Further research is required into the following promising interventions: the dose of progesterone for luteal phase support, peripheral blood mononuclear cells for women with recurrent implantation failure, glucocorticoids in women undergoing IVF, low-molecular-weight heparin for unexplained subfertility, intrauterine hCG at the time of cleavage stage embryo or blastocyst transfer and low oxygen concentrations in embryo culture. In addition, there is a need for high-quality, well-designed RCTs in the field of reproductive surgery. Finally, further research is needed to demonstrate the integrated effects of non-pharmacological lifestyle interventions.

The neglected members of the family: non-BRCA mutations in the Fanconi anemia/BRCA pathway and reproduction.

Vanni VS, Campo G, Cioffi R … +7 more , Papaleo E, Salonia A, Viganò P, Lambertini M, Candiani M, Meirow D, Orvieto R

Hum Reprod Update · 2022 Feb · PMID 35043201 · Publisher ↗

BACKGROUND: BReast CAncer (BRCA) genes are extensively studied in the context of fertility and reproductive aging. BRCA proteins are part of the DNA repair Fanconi anemia (FA)/BRCA pathway, in which more than 20 proteins... BACKGROUND: BReast CAncer (BRCA) genes are extensively studied in the context of fertility and reproductive aging. BRCA proteins are part of the DNA repair Fanconi anemia (FA)/BRCA pathway, in which more than 20 proteins are implicated. According to which gene is mutated and which interactions are lost owing to the mutation, carriers and patients with monoallelic or biallelic FA/BRCA mutations exhibit very different phenotypes, from overt FA to cancer predisposition or no pathological implications. The effect of the so far neglected non-BRCA FA mutations on fertility also deserves consideration. OBJECTIVE AND RATIONALE: As improved treatments allow a longer life expectancy in patients with biallelic FA mutations and overt FA, infertility is emerging as a predominant feature. We thus reviewed the mechanisms for such a manifestation, as well as whether they also occur in monoallelic carriers of FA non-BRCA mutations. SEARCH METHODS: Electronic databases PUBMED, EMBASE and CENTRAL were searched using the following term: 'fanconi' OR 'FANC' OR 'AND' 'fertility' OR 'pregnancy' OR 'ovarian reserve' OR 'spermatogenesis' OR 'hypogonadism'. All pertinent reports in the English-language literature were retrieved until May 2021 and the reference lists were systematically searched in order to identify any potential additional studies. OUTCOMES: Biallelic FA mutations causing overt FA disease are associated with premature ovarian insufficiency (POI) occurring in the fourth decade in women and with primary non-obstructive azoospermia (NOA) in men. Hypogonadism in FA patients seems mainly associated with a defect in primordial germ cell proliferation in fetal life. In recent small, exploratory whole-exome sequencing studies, biallelic clinically occult mutations in the FA complementation group A (Fanca) and M (Fancm) genes were found in otherwise healthy patients with isolated NOA or POI, and also monoallelic carrier status for a loss-of-function mutation in Fanca has been implicated as a possible cause for POI. In those patients with known monoallelic FA mutations undergoing pre-implantation genetic testing, poor assisted reproduction outcomes are reported. However, the mechanisms underlying the repeated failures and the high miscarriage rates observed are not fully known. WIDER IMPLICATIONS: The so far 'neglected' members of the FA/BRCA family will likely emerge as a relevant focus of investigation in the genetics of reproduction. Several (rather than a single) non-BRCA genes might be implicated. State-of-the-art methods, such as whole-genome/exome sequencing, and further exploratory studies are required to understand the prevalence and mechanisms for occult FA mutations in infertility and recurrent miscarriage.

DNA damage in preimplantation embryos and gametes: specification, clinical relevance and repair strategies.

Musson R, Gąsior Ł, Bisogno S … +1 more , Ptak GE

Hum Reprod Update · 2022 May · PMID 35021196 · Full text

BACKGROUND: DNA damage is a hazard that affects all cells of the body. DNA-damage repair (DDR) mechanisms are in place to repair damage and restore cellular function, as are other damage-induced processes such as apoptos... BACKGROUND: DNA damage is a hazard that affects all cells of the body. DNA-damage repair (DDR) mechanisms are in place to repair damage and restore cellular function, as are other damage-induced processes such as apoptosis, autophagy and senescence. The resilience of germ cells and embryos in response to DNA damage is less well studied compared with other cell types. Given that recent studies have described links between embryonic handling techniques and an increased likelihood of disease in post-natal life, an update is needed to summarize the sources of DNA damage in embryos and their capacity to repair it. In addition, numerous recent publications have detailed novel techniques for detecting and repairing DNA damage in embryos. This information is of interest to medical or scientific personnel who wish to obtain undamaged embryos for use in offspring generation by ART. OBJECTIVE AND RATIONALE: This review aims to thoroughly discuss sources of DNA damage in male and female gametes and preimplantation embryos. Special consideration is given to current knowledge and limits in DNA damage detection and screening strategies. Finally, obstacles and future perspectives in clinical diagnosis and treatment (repair) of DNA damaged embryos are discussed. SEARCH METHODS: Using PubMed and Google Scholar until May 2021, a comprehensive search for peer-reviewed original English-language articles was carried out using keywords relevant to the topic with no limits placed on time. Keywords included 'DNA damage repair', 'gametes', 'sperm', 'oocyte', 'zygote', 'blastocyst' and 'embryo'. References from retrieved articles were also used to obtain additional articles. Literature on the sources and consequences of DNA damage on germ cells and embryos was also searched. Additional papers cited by primary references were included. Results from our own studies were included where relevant. OUTCOMES: DNA damage in gametes and embryos can differ greatly based on the source and severity. This damage affects the development of the embryo and can lead to long-term health effects on offspring. DDR mechanisms can repair damage to a certain extent, but the factors that play a role in this process are numerous and altogether not well characterized. In this review, we describe the multifactorial origin of DNA damage in male and female gametes and in the embryo, and suggest screening strategies for the selection of healthy gametes and embryos. Furthermore, possible therapeutic solutions to decrease the frequency of DNA damaged gametes and embryos and eventually to repair DNA and increase mitochondrial quality in embryos before their implantation is discussed. WIDER IMPLICATIONS: Understanding DNA damage in gametes and embryos is essential for the improvement of techniques that could enhance embryo implantation and pregnancy success. While our knowledge about DNA damage factors and regulatory mechanisms in cells has advanced greatly, the number of feasible practical techniques to avoid or repair damaged embryos remains scarce. Our intention is therefore to focus on strategies to obtain embryos with as little DNA damage as possible, which will impact reproductive biology research with particular significance for reproductive clinicians and embryologists.

The putative roles of FSH and AMH in the regulation of oocyte developmental competence: from fertility prognosis to mechanisms underlying age-related subfertility.

Buratini J, Dellaqua TT, Dal Canto M … +4 more , La Marca A, Carone D, Mignini Renzini M, Webb R

Hum Reprod Update · 2022 Feb · PMID 34969065 · Publisher ↗

BACKGROUND: Fertility loss during female ageing is associated with increasing basal FSH and decreasing anti-Müllerian hormone (AMH) concentrations, together with compromised oocyte quality, presumably due to increased ox... BACKGROUND: Fertility loss during female ageing is associated with increasing basal FSH and decreasing anti-Müllerian hormone (AMH) concentrations, together with compromised oocyte quality, presumably due to increased oxidative stress (OS) and DNA damage, as well as reduced metabolic and meiotic competences. Basal FSH and AMH circulatory concentrations have been broadly utilized as IVF success predictors, regardless of fluctuations in prognostic accuracy; basal FSH and AMH perform better in pre-advanced maternal age (AMA: >35 years) and AMA patients, respectively. The relationships between FSH and AMH intrafollicular levels and IVF outcomes suggest, nevertheless, that both hormones regulate oocyte competence, supporting the hypothesis that changes in FSH/AMH levels cause, at least in part, oocyte quality degradation during ageing. To understand the reasons behind the fluctuations in FSH and AMH prognostic accuracies and to clarify their participation in mechanisms determining oocyte competence and age-related subfertility, a deeper knowledge of the regulation of FSH and AMH intrafollicular signalling during the female reproductive lifespan, and of their effects on the cumulus-oocyte complex, is required. OBJECTIVE AND RATIONALE: An extensive body of information on the regulation of FSH and AMH intrafollicular availability and signalling, as well as on the control of folliculogenesis and oocyte metabolism, has been accumulated. However, these datasets have been explored within the relatively narrow boundaries of their specific subjects. Given the aforementioned gaps in knowledge and their clinical relevance, herein we integrate clinical and basic data, within a wide biological perspective, aiming to shed light on (i) the reasons for the variability in the accuracy of serum FSH and AMH as fertility markers, and on (ii) the potential roles of these hormones in mechanisms regulating oocyte quality, particularly those associated with ageing. SEARCH METHODS: The PubMed database encompassing the period between 1960 and 2021 was searched. Principal search terms were FSH, FSH receptor, AMH, oocyte, maternal age, cumulus, transzonal projections (TZPs), actin, OS, redox, reactive oxygen species, mitochondria, DNA damage, DNA repair, aneuploidy, spindle, meiosis, gene expression, transcription, translation, oocyte secreted factors (OSFs), cAMP, cyclic guanosine monophosphate, natriuretic peptide C, growth differentiation factor 9, bone morphogenetic protein 15 and fibroblast growth factor. OUTCOMES: Our analysis suggests that variations in the accuracy of fertility prognosis reflect a modest association between circulatory AMH levels and oocyte quality as well as increasing basal FSH inter-cycle variability with age. In addition, the basic and clinical data articulated herein support the hypothesis that increased intrafollicular FSH levels, as maternal age advances, may override the physiological protective influences of AMH and OSFs against excessive FSH signalling in cumulus cells. This would result in the disruption of oocyte homeostasis via reduced TZP-mediated transfer of cumulus-derived molecules essential for meiotic competence, gene expression, redox activity and DNA repair. WIDER IMPLICATIONS: In-depth data analysis, encompassing a wide biological perspective has revealed potential causative mechanisms of age-related subfertility triggered by alterations in FSH/AMH signalling during the female reproductive life. Insights from new mechanistic models arising from this analysis should contribute to advancing our comprehension of oocyte biology in humans and serve as a valuable reference for novel AMA subfertility treatments aimed at improving oocyte quality through the modulation of AMH/FSH action.

Obstetric and perinatal outcomes of singleton pregnancies after blastocyst-stage embryo transfer compared with those after cleavage-stage embryo transfer: a systematic review and cumulative meta-analysis.

Marconi N, Allen CP, Bhattacharya S … +1 more , Maheshwari A

Hum Reprod Update · 2022 Feb · PMID 34967896 · Publisher ↗

BACKGROUND: Extended embryo culture to blastocyst stage is widely used in IVF and is the default strategy in most clinics. The last decade has witnessed a growing interest in obstetric-perinatal outcomes following blasto... BACKGROUND: Extended embryo culture to blastocyst stage is widely used in IVF and is the default strategy in most clinics. The last decade has witnessed a growing interest in obstetric-perinatal outcomes following blastocyst transfer. Recent studies have challenged the conclusions of systematic reviews that associate risks of preterm birth (PTB) and large for gestational age (LGA) babies with blastocyst transfer. A higher proportion of blastocysts is transferred as frozen-thawed embryos, which may also have added implications. OBJECTIVE AND RATIONALE: The aim of this study was to conduct an updated systematic review of the obstetric-perinatal outcomes in singleton pregnancies following blastocyst-stage transfer compared to cleavage-stage transfer in IVF/ICSI cycles. Where deemed appropriate, data were combined in cumulative meta-analyses. SEARCH METHODS: Data sources from Medline, EMBASE, CINAHL, Web of Science, the Cochrane Central Register of Clinical Trials and the International Clinical Trials Registry Platform (ICTRP) (1980-2020) were searched using combinations of relevant keywords. Searches had no language restrictions and were limited to human studies. Observational studies and randomized controlled trials comparing obstetric-perinatal outcomes between singleton pregnancies after blastocyst-stage transfer and those after cleavage-stage transfer in IVF/ICSI cycles were sought. Two independent reviewers extracted data in 2 × 2 tables and assessed the methodological quality of the relevant studies using the Critical Appraisal Skills Programme scoring. Cumulative meta-analyses were carried out with independent analysis of pregnancies after fresh and frozen embryo transfers, using the Comprehensive Meta-Analysis software. If provided by included studies, adjusted effect sizes were combined in a sensitivity analysis. OUTCOMES: A total of 35 studies were included (n = 520 769 singleton pregnancies). Outcome data suggest singleton pregnancies following fresh blastocyst transfer were associated with higher risk of LGA (risk ratio (RR) 1.14; 95% CI 1.05-1.24) and very PTB (RR 1.17; 95% CI 1.08-1.26) compared to fresh cleavage-stage transfer. Singleton pregnancies following frozen blastocyst transfer were associated with higher risks of LGA (RR 1.17; 95% CI 1.08-1.27), PTB (RR 1.13; 95% CI 1.03-1.24) and caesarean section (RR 1.08; 95% CI 1.03-1.13) but lower risks of small for gestational age (RR 0.84, 95% CI 0.74-0.95) and perinatal mortality (RR 0.70; 95% CI 0.58-0.86). Increased risks of LGA and PTB after frozen blastocyst transfer persisted in the sensitivity analysis, which also showed a significantly increased risk of PTB after fresh blastocyst transfer. Cumulative meta-analyses revealed consistency in prevalence and magnitude of risks for a number of years. Data on other perinatal outcomes are still evolving. WIDER IMPLICATIONS: While the available evidence is predominantly reassuring in the context of blastocyst-stage embryo transfer, observational data suggest that blastocyst transfer is associated with a higher risk of LGA. This holds true irrespective of fresh or frozen transfer. Meta-analysis of adjusted data showed an increased risk of PTB with fresh and frozen blastocyst transfer. However, the quality of available evidence ranges from low to very low. Although blastocyst-stage embryo transfer remains the default position in most centres, based on individual risk profile we may need to consider cleavage-stage embryo transfer in some to mitigate the risk of LGA/PTB.

Autophagy: a multifaceted player in the fate of sperm.

Wang M, Zeng L, Su P … +3 more , Ma L, Zhang M, Zhang YZ

Hum Reprod Update · 2022 Feb · PMID 34967891 · Full text

BACKGROUND: Autophagy is an intracellular catabolic process of degrading and recycling proteins and organelles to modulate various physiological and pathological events, including cell differentiation and development. Em... BACKGROUND: Autophagy is an intracellular catabolic process of degrading and recycling proteins and organelles to modulate various physiological and pathological events, including cell differentiation and development. Emerging data indicate that autophagy is closely associated with male reproduction, especially the biosynthetic and catabolic processes of sperm. Throughout the fate of sperm, a series of highly specialized cellular events occur, involving pre-testicular, testicular and post-testicular events. Nonetheless, the most fundamental question of whether autophagy plays a protective or harmful role in male reproduction, especially in sperm, remains unclear. OBJECTIVE AND RATIONALE: We summarize the functional roles of autophagy in the pre-testicular (hypothalamic-pituitary-testis (HPG) axis), testicular (spermatocytogenesis, spermatidogenesis, spermiogenesis, spermiation) and post-testicular (sperm maturation and fertilization) processes according to the timeline of sperm fate. Additionally, critical mechanisms of the action and clinical impacts of autophagy on sperm are identified, laying the foundation for the treatment of male infertility. SEARCH METHODS: In this narrative review, the PubMed database was used to search peer-reviewed publications for summarizing the functional roles of autophagy in the fate of sperm using the following terms: 'autophagy', 'sperm', 'hypothalamic-pituitary-testis axis', 'spermatogenesis', 'spermatocytogenesis', 'spermatidogenesis', 'spermiogenesis', 'spermiation', 'sperm maturation', 'fertilization', 'capacitation' and 'acrosome' in combination with autophagy-related proteins. We also performed a bibliographic search for the clinical impact of the autophagy process using the keywords of autophagy inhibitors such as 'bafilomycin A1', 'chloroquine', 'hydroxychloroquine', '3-Methyl Adenine (3-MA)', 'lucanthone', 'wortmannin' and autophagy activators such as 'rapamycin', 'perifosine', 'metformin' in combination with 'disease', 'treatment', 'therapy', 'male infertility' and equivalent terms. In addition, reference lists of primary and review articles were reviewed for additional relevant publications. All relevant publications until August 2021 were critically evaluated and discussed on the basis of relevance, quality and timelines. OUTCOMES: (i) In pre-testicular processes, autophagy-related genes are involved in the regulation of the HPG axis; and (ii) in testicular processes, mTORC1, the main gate to autophagy, is crucial for spermatogonia stem cell (SCCs) proliferation, differentiation, meiotic progression, inactivation of sex chromosomes and spermiogenesis. During spermatidogenesis, autophagy maintains haploid round spermatid chromatoid body homeostasis for differentiation. During spermiogenesis, autophagy participates in acrosome biogenesis, flagella assembly, head shaping and the removal of cytoplasm from elongating spermatid. After spermatogenesis, through PDLIM1, autophagy orchestrates apical ectoplasmic specialization and basal ectoplasmic specialization to handle cytoskeleton assembly, governing spermatid movement and release during spermiation. In post-testicular processes, there is no direct evidence that autophagy participates in the process of capacitation. However, autophagy modulates the acrosome reaction, paternal mitochondria elimination and clearance of membranous organelles during fertilization. WIDER IMPLICATIONS: Deciphering the roles of autophagy in the entire fate of sperm will provide valuable insights into therapies for diseases, especially male infertility.

Chances of pregnancy and live birth among women undergoing conservative management of early-stage endometrial cancer: a systematic review and meta-analysis.

Herrera Cappelletti E, Humann J, Torrejón R … +1 more , Gambadauro P

Hum Reprod Update · 2022 Feb · PMID 34935045 · Full text

BACKGROUND: Endometrial cancer is common and usually occurs after menopause, but the number of women diagnosed during reproductive age is increasing. The standard treatment including hysterectomy is effective but causes... BACKGROUND: Endometrial cancer is common and usually occurs after menopause, but the number of women diagnosed during reproductive age is increasing. The standard treatment including hysterectomy is effective but causes absolute uterine factor infertility. In order to avoid or postpone surgery, conservative management of endometrial cancer (CMEC) has been proposed for younger women who want to retain their fertility. OBJECTIVE AND RATIONALE: The main objective of this study was to estimate the chances of pregnancy and live birth for women with early-stage endometrial cancer (EEC) who are managed conservatively for fertility preservation. SEARCH METHODS: The PRISMA recommendations for systematic reviews and meta-analyses were followed. Structured searches were performed in PubMed, Embase and the Cochrane Library, from inception until 13 June 2021. Inclusion was based on the following criteria: group or subgroup of women with Clinical Stage IA, well-differentiated, endometrioid endometrial cancer (from now on, EEC); CMEC for fertility preservation; and reported frequencies of women achieving pregnancy and/or live birth after CMEC. The following exclusion criteria applied: impossibility to isolate/extract outcome data of interest; second-line CMEC for persistent/recurrent disease; CMEC in the presence of synchronous tumours; case reports; non-original or duplicated data; and articles not in English. Qualitative synthesis was performed by means of tabulation and narrative review of the study characteristics. Study quality was assessed with an ad hoc instrument and several moderator and sensitivity analyses were performed. OUTCOMES: Out of 1275 unique records, 133 were assessed in full-text and 46 studies were included in the review. Data from 861 women with EEC undergoing CMEC were available. Progestin-based treatment was reported in all but three studies (93.5%; 836 women). Complete response to treatment was achieved in 79.7% of women, with 35.3% of them having a disease recurrence during follow-up. Of 286 pregnancies obtained after CMEC; 69.4% led to live birth (9% of them multiple births) and 66.7% were achieved through fertility treatment. Based on random-effects meta-analyses, women treated with progestin-based CMEC have a 26.7% chance of achieving pregnancy (95% CI 21.3-32.3; I2 = 53.7%; 42 studies, 826 women) and a 20.5% chance to achieve a live birth (95% CI 15.7-25.8; I2 = 40.2%; 39 studies, 650 women). Sample size, average age, publication year, study design and quality score were not associated with the outcomes of progestin-based CMEC in moderator analyses with meta-regression. However, mean follow-up length (in months) was positively associated with the chances of pregnancy (regression coefficient [B] = 0.003; 95% CI 0.001-0.005; P = 0.006) and live birth (B = 0.005; 95% CI 0.003-0.007; P < 0.001). In sensitivity analyses, the highest chances of live birth were estimated in subsets of studies including only women of age 35 or younger (30.7%), the combination of progestins with hysteroscopic resection (30.7%), or at least 3 years of follow-up (42.4%). WIDER IMPLICATIONS: Progestin-based CMEC is viable for women with well-differentiated, Clinical Stage 1A, endometrioid endometrial cancer who want to preserve their fertility, but there is room for improvement as only one-fifth of them are estimated to achieve live birth according to this meta-analysis. Further investigations on prognosis-driven selection, hysteroscopic resection and long-term surveillance are arguably needed to improve the reproductive outcomes of CMEC.

The role of cellular senescence in female reproductive aging and the potential for senotherapeutic interventions.

Secomandi L, Borghesan M, Velarde M … +1 more , Demaria M

Hum Reprod Update · 2022 Feb · PMID 34918084 · Full text

BACKGROUND: Advanced maternal age is associated with decreased oocyte quantity and quality as well as uterine and placental dysfunctions. These changes lead to infertility, pregnancy complications and birth defects in th... BACKGROUND: Advanced maternal age is associated with decreased oocyte quantity and quality as well as uterine and placental dysfunctions. These changes lead to infertility, pregnancy complications and birth defects in the offspring. As the mean age of giving birth is increasing worldwide, prevention of age-associated infertility and pregnancy complications, along with the more frequent use of ART, become extremely important. Currently, significant research is being conducted to unravel the mechanisms underlying female reproductive aging. Among the potential mechanisms involved, recent evidence has suggested a contributing role for cellular senescence, a cellular state of irreversible growth arrest characterized by a hypersecretory and pro-inflammatory phenotype. Elucidating the role of senescence in female reproductive aging holds the potential for developing novel and less invasive therapeutic measures to prevent or even reverse female reproductive aging and increase offspring wellbeing. OBJECTIVE AND RATIONALE: The review will summarize the positive and negative implications of cellular senescence in the pathophysiology of the female reproductive organs during aging and critically explore the use of novel senotherapeutics aiming to reverse and/or eliminate their detrimental effects. The focus will be on major senescence mechanisms of the ovaries, the uterus, and the placenta, as well as the potential and risks of using senotherapies that have been discovered in recent years. SEARCH METHODS: Data for this review were identified by searches of MEDLINE, PubMed and Google Scholar. References from relevant articles using the search terms 'Cellular Senescence', 'Aging', 'Gestational age', 'Maternal Age', 'Anti-aging', 'Uterus', 'Pregnancy', 'Fertility', 'Infertility', 'Reproduction', 'Implant', 'Senolytic', 'Senostatic', 'Senotherapy' and 'Senotherapeutic' where selected. A total of 182 articles published in English between 2005 and 2020 were included, 27 of which focus on potential senotherapies for reproductive aging. Exclusion criteria were inclusion of the terms 'male' and 'plants'. OUTCOMES: Aging is a major determinant of reproductive wellbeing. Cellular senescence is a basic aging mechanism, which can be exploited for therapeutic interventions. Within the last decade, several new strategies for the development and repurposing of drugs targeting senescent cells have emerged, such as modulators of the anti-inflammatory response, oxidative stress, DNA damage, and mitochondria and protein dysfunctions. Several studies of female reproductive aging and senotherapies have been discussed that show promising results for future interventions. WIDER IMPLICATIONS: In most countries of the Organization for Economic Co-operation and Development, the average age at which women give birth is above 30 years. Currently, in countries such as the Netherlands, Australia, Spain, Finland, Germany and the UK, birth rates among 30- to 34-year-olds are now higher than in any other age groups. This review will provide new knowledge and scientific advancement on the senescence mechanisms during female reproductive aging, and benefit fundamental and clinical scientists and professionals in the areas of reproduction, cancer, immunobiology and fibrosis.

Barriers and facilitators for the inclusion of fertility care in reproductive health policies in Africa: a qualitative evidence synthesis.

Afferri A, Allen H, Booth A … +3 more , Dierickx S, Pacey A, Balen J

Hum Reprod Update · 2022 Feb · PMID 34888683 · Publisher ↗

BACKGROUND: Infertility affects over 50 million couples worldwide and impacts people's social and emotional wellbeing. In low- and middle-income countries, particularly across Africa, the inclusion of fertility care into... BACKGROUND: Infertility affects over 50 million couples worldwide and impacts people's social and emotional wellbeing. In low- and middle-income countries, particularly across Africa, the inclusion of fertility care into reproductive health (RH) policies remains fragmented or non-existent. OBJECTIVE AND RATIONALE: This review aims to provide a framework for understanding the inclusion (or lack thereof) of fertility care in RH policies in African settings. It synthesizes the barriers and facilitators to such inclusion, with a view to uncovering the positioning of fertility care in broader health systems and on the agendas of key stakeholders such as health policymakers and practitioners. SEARCH METHODS: A qualitative evidence synthesis was performed, systematically searching papers and grey literature. Searches were conducted in MEDLINE, EMBASE, CINAHL, Web of Science and Scopus between February and April 2020. No date restrictions were applied. Language was limited to publications written in English and French. Two reviewers independently screened titles and abstracts, and extracted data, applying thematic coding. The quality of the included papers was evaluated using The Joanna Briggs Institute Checklist for Text and Opinion Papers. OUTCOMES: The search identified 744 papers, of which 20 were included. Findings were organized under four cross-cutting categories, namely: perceived importance of infertility; influence of policy context; resource availability and access; and perceived quality of care. Across these categories, key barriers to the inclusion of fertility care in RH policies were limited political commitment, under-recognition of the burden of infertility and high costs associated with ART. Conversely, facilitators comprised specialized training on infertility for healthcare providers, standard procedures for ART safety and guidelines and North-South/South-South collaborations. WIDER IMPLICATIONS: The inclusion of fertility care in African RH policies depends upon factors that include the recognition of infertility as a disease, strong political engagement and proactivity and affordability of ART through opportunities for partnership with the private sector, which ease costs on the public health system. Further qualitative and quantitative research, including context-specific analysis and in-depth comparative approaches across diverse African countries, will help to delineate differential impacts of local and global factors on fertility care to address this neglected RH issue.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies.

Tempest N, Hill CJ, Maclean A … +4 more , Marston K, Powell SG, Al-Lamee H, Hapangama DK

Hum Reprod Update · 2022 Feb · PMID 34875046 · Full text

BACKGROUND: Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the... BACKGROUND: Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement. OBJECTIVE AND RATIONALE: The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization. SEARCH METHODS: An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included. OUTCOMES: The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates. WIDER IMPLICATIONS: The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

Clinical application of aromatase inhibitors to treat male infertility.

Yang C, Li P, Li Z

Hum Reprod Update · 2021 Dec · PMID 34871401 · Publisher ↗

BACKGROUND: Infertility affects 15% of men and contributes to nearly half of all cases of infertility. Infertile men usually have impaired spermatogenesis, presenting as azoospermia or various degrees of asthenospermia a... BACKGROUND: Infertility affects 15% of men and contributes to nearly half of all cases of infertility. Infertile men usually have impaired spermatogenesis, presenting as azoospermia or various degrees of asthenospermia and oligozoospermia. Spermatogenesis is a complex and coordinated process, which is under precise modulation by the hypothalamic-pituitary-gonadal (HPG) axis. An aberrant hormone profile, especially an imbalance between testosterone (T) and estradiol (E2), plays an essential role in male infertility. In the male, E2 is produced mainly from the conversion of T by the aromatase enzyme. Theoretically, reducing an abnormally elevated T:E2 ratio using aromatase inhibitors (AIs) could restore the balance between T and E2 and optimize the HPG axis to support spermatogenesis. For decades, AIs have been used to treat male infertility empirically. However, owing to the lack of large-scale randomized controlled studies and basic research, the treatment efficacy and safety of AIs in male infertility remain controversial. Therefore, there is a need to summarize the clinical trials and relevant basic research on the application of AIs in the treatment of male infertility. OBJECTIVE AND RATIONALE: In this narrative review, we summarized the application of AIs in the treatment of male infertility, including the pharmacological mechanisms involved, clinical trials focused on patients with different types of infertility, factors affecting treatment efficacy and the side-effects. SEARCH METHODS: A literature search was performed using MEDLINE/PubMed and EMBASE, focusing on publications in the past four decades concerning the use of AIs for treating male infertility. The search terms included AI, male infertility, letrozole, anastrozole, testolactone, azoospermia, oligozoospermia, aromatase polymorphisms, obesity and antiestrogens, in various combinations. OUTCOMES: Clinical studies demonstrate that AIs, especially nonsteroidal letrozole and anastrozole, could significantly inhibit the production of E2 and its negative feedback on the HPG axis, resulting in increased T and FSH production as well as improved semen parameters in infertile men. Large-scale surveys suggest that obesity may result in symptoms of hypogonadism in both fertile and infertile males, such as decreased semen quality and attenuated sexual function, which can be improved by AIs treatment. Polymorphisms of the aromatase gene CYP19A1, including single nucleotide polymorphisms and tetranucleotide TTTA repeats polymorphism (TTTAn), also influence hormone profiles, semen quality and treatment efficacy of AIs in male hypogonadotropic hypogonadism and infertility. The side-effects of AIs in treating male infertility are various, but most are mild and well tolerated. WIDER IMPLICATIONS: The application of AIs in treating male infertility has been off-label and empirical for decades. This narrative review has summarized the target patients, dose, treatment duration and side-effects of AIs. Polymorphisms of CYP19A1 that may affect AIs treatment efficacy were also summarized, but a full understanding of the mechanisms involved in AIs action requires further study.

Effects of different frozen embryo transfer regimens on abnormalities of fetal weight: a systematic review and meta-analysis.

Rosalik K, Carson S, Pilgrim J … +4 more , Luizzi J, Levy G, Heitmann R, Pier B

Hum Reprod Update · 2021 Dec · PMID 34865039 · Publisher ↗

BACKGROUND: Reported increases in maternal and perinatal morbidity (including macrosomia, large for gestational age (LGA), cesarean section, hemorrhage and hypertensive disorders of pregnancy) following frozen embryo tra... BACKGROUND: Reported increases in maternal and perinatal morbidity (including macrosomia, large for gestational age (LGA), cesarean section, hemorrhage and hypertensive disorders of pregnancy) following frozen embryo transfer (FET) cycles may be associated with the lack of a corpus luteum seen in programmed FET. Given the growing number of studies comparing outcomes between natural FET and programmed FET cycles, a meta-analysis would prove useful to detect the presence of abnormalities in fetal birth weight in patients undergoing natural and programmed FET cycles. OBJECTIVE AND RATIONALE: The aim of this study was to provide a systematic review and meta-analysis of the effects of natural versus programmed methods of endometrial preparation for FET cycles on fetal weight and the risks of LGA and macrosomia. SEARCH METHODS: A literature search using MEDLINE, SCOPUS, EMBASE and clinicaltrials.gov was conducted for published research comparing neonatal outcomes in natural FET and programmed FET cycles. Primary outcomes of interest were fetal weight, macrosomia and LGA. Studies were included if the following criteria were met: study contained cohorts of NFET and programmed FET with outcome data of birth weight, large for gestational data and/or macrosomia. The data are presented as average weight and odds ratio (OR) with 95% confidence interval (CI) with fixed- or random-effects meta-analysis between cohorts of NFET and programmed FET cycles. Bias was assessed using Newcastle-Ottawa quality assessment scale for the 14 included studies. Multiple subgroup analyses were performed to assess for effect of the true natural cycle (defined as no ovulation trigger medication use) and the day of embryo transfer on fetal weight parameters compared with programmed cycle FET. OUTCOMES: A total of 879 studies were identified, with 15 meeting inclusion the criteria. The studies varied with respect to country of origin, definition of natural cycle FET and type of progesterone supplementation used. The included studies had similar gestational ages at the time of birth. Programmed FET cycles resulted in a higher fetal weight compared with natural FET cycles (mean difference 47.38 gp = 0.04). Programmed FET cycles were also at higher risk for macrosomia (OR 1.15, 95% CI 1.06-1.26) and LGA (OR 1.10, 95% CI 1.02-1.19) compared with natural FET cycles. Subgroup analyses demonstrated that programmed FET cycles resulted in a higher fetal weight compared with true natural FET (mean difference 62.18 gp = 0.0001) cycles. Cleavage stage embryo transfers had an increased risk of LGA (OR 1.27, 95% CI 1.00-1.62) and an increased risk of macrosomia (OR 1.25, 95% CI 1.08-1.44) in programmed FET cycles compared with natural FET cycles. Blastocyst transfer in programmed FET cycles resulted in no difference in risk of macrosomia but an increased risk of LGA (OR 1.13, 95% CI 1.06-1.21) compared with natural FET cycles. WIDER IMPLICATIONS: Programmed endometrial preparation for FET cycles had a significant effect, causing increased fetal birth weight and increased risks of LGA and macrosomia. The numbers of studies in the subgroup analyses were too low to determine reliable results. Further prospective randomized trials are needed to determine whether the changes seen in the observational trials are indeed accurate.

The role of gut and genital microbiota and the estrobolome in endometriosis, infertility and chronic pelvic pain.

Salliss ME, Farland LV, Mahnert ND … +1 more , Herbst-Kralovetz MM

Hum Reprod Update · 2021 Dec · PMID 34718567 · Publisher ↗

BACKGROUND: Endometriosis is a chronic, burdensome condition that is historically understudied. Consequently, there is a lack of understanding of the etiology of the disease and its associated symptoms, including inferti... BACKGROUND: Endometriosis is a chronic, burdensome condition that is historically understudied. Consequently, there is a lack of understanding of the etiology of the disease and its associated symptoms, including infertility and chronic pelvic pain (CPP). Endometriosis development is influenced by estrogen metabolism and inflammation, which are modulated by several factors including the microbiome and the estrobolome (the collection of genes encoding estrogen-metabolizing enzymes in the gut microbiome). Therefore, there is increasing interest in understanding the role of microbiota in endometriosis etiology. OBJECTIVE AND RATIONALE: To date, there is no cure for endometriosis and treatment options often are ineffective. This manuscript will review the potential relationship between the microbiome and endometriosis, infertility and CPP and highlight the available data on the microbiome in relation to endometriosis and its related symptoms. The overarching goal of this manuscript is to inform future microbiome research that will lead to a deeper understanding of the etiology of the disease and possible diagnostic modalities and treatments. The potential impact of the microbiome on estrogen regulation modulated by the estrobolome, as well as inflammation and other endometriosis-promoting mechanisms within the genital tract, will be reviewed. The methodological limitations of microbiome-related studies will be critically assessed to provide improved guidelines for future microbiome and clinical studies. SEARCH METHODS: PubMed databases were searched using the following keywords: endometriosis AND microbiome, infertility AND microbiome, pelvic pain AND microbiome, IVF (in-vitro fertilization) AND microbiome, endometriosis AND infertility. Clinical and preclinical animal trials that were eligible for review, and related to microbiome and endometriosis, infertility or CPP were included. All available manuscripts were published in 2002-2021. OUTCOMES: In total, 28 clinical and 6 animal studies were included in the review. In both human and animal studies, bacteria were enriched in endometriosis groups, although there was no clear consensus on specific microbiota compositions that were associated with endometriosis, and no studies included infertility or CPP with endometriosis. However, bacterial vaginosis-associated bacteria and Lactobacillus depletion in the cervicovaginal microbiome were associated with endometriosis and infertility in the majority (23/28) of studies. Interpretation of endometrial studies is limited owing to a variety of methodological factors, discussed in this review. In addition, metadata outlining antibiotic usage, age, race/ethnicity, menopausal status and timing of sample collection in relation to diagnosis of endometriosis was not consistently reported. Animal studies (6/6) support a bidirectional relationship between the gut microbiota and endometriosis onset and progression. WIDER IMPLICATIONS: There is evidence that a dysbiotic gut or genital microbiota is associated with multiple gynecologic conditions, with mounting data supporting an association between the microbiome and endometriosis and infertility. These microbiomes likely play a role in the gut-brain axis, which further supports a putative association with the spectrum of symptoms associated with endometriosis, including infertility and CPP. Collectively, this review highlights the demand for more rigorous and transparent methodology and controls, consistency across the field, and inclusion of key demographic and clinical characteristics of disease and comparison participants. Rigorous study designs will allow for a better understanding of the potential role of the microbiome in endometriosis etiology and the relationship to other disorders of the female reproductive tract.

Reply: The missing role of diagnosis of confined placental mosaicism in the management of fetal growth restriction.

Eggenhuizen GM, Go A, Galjaard RJ

Hum Reprod Update · 2021 Dec · PMID 34642759 · Full text

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