NobleBlocks

MRC Centre for Reproductive Health

facilityEdinburgh, United Kingdom

Research output, citation impact, and the most-cited recent papers from MRC Centre for Reproductive Health (United Kingdom). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
5.5K
Citations
667.4K
h-index
309
i10-index
7.8K
Also known as
MRC Centre for Reproductive Health

Top-cited papers from MRC Centre for Reproductive Health

ESHRE guideline: management of women with endometriosis
G.A.J. Dunselman, Nathalie Vermeulen, Christian M. Becker, Carlos Calhaz–Jorge +4 more
2014· Human Reproduction2.2Kdoi:10.1093/humrep/det457

STUDY QUESTION: What is the optimal management of women with endometriosis based on the best available evidence in the literature? SUMMARY ANSWER: Using the structured methodology of the Manual for ESHRE Guideline Development, 83 recommendations were formulated that answered the 22 key questions on optimal management of women with endometriosis. WHAT IS KNOWN ALREADY: The European Society of Human Reproduction and Embryology (ESHRE) guideline for the diagnosis and treatment of endometriosis (2005) has been a reference point for best clinical care in endometriosis for years, but this guideline was in need of updating. STUDY DESIGN, SIZE, DURATION: This guideline was produced by a group of experts in the field using the methodology of the Manual for ESHRE Guideline Development, including a thorough systematic search of the literature, quality assessment of the included papers up to January 2012 and consensus within the guideline group on all recommendations. To ensure input from women with endometriosis, a patient representative was part of the guideline development group. In addition, patient and additional clinical input was collected during the scoping and review phase of the guideline. PARTICIPANTS/MATERIALS, SETTING, METHODS: NA. MAIN RESULTS AND THE ROLE OF CHANCE: The guideline provides 83 recommendations on diagnosis of endometriosis and on the treatment of endometriosis-associated pain and infertility, on the management of women in whom the disease is found incidentally (without pain or infertility), on prevention of recurrence of disease and/or painful symptoms, on treatment of menopausal symptoms in patients with a history of endometriosis and on the possible association of endometriosis and malignancy. LIMITATIONS, REASONS FOR CAUTION: We identified several areas in care of women with endometriosis for which robust evidence is lacking. These areas were addressed by formulating good practice points (GPP), based on the expert opinion of the guideline group members. WIDER IMPLICATIONS OF THE FINDINGS: Since 32 out of the 83 recommendations for the management of women with endometriosis could not be based on high level evidence and therefore were GPP, the guideline group formulated research recommendations to guide future research with the aim of increasing the body of evidence. STUDY FUNDING/COMPETING INTEREST(S): The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the implementation of the guideline. The guideline group members did not receive payment. All guideline group members disclosed any relevant conflicts of interest (see Conflicts of interest). TRIAL REGISTRATION NUMBER: NA.

Brain charts for the human lifespan
Richard A. I. Bethlehem, Jakob Seidlitz, Simon R. White, Jacob W. Vogel +4 more
2022· Nature1.7Kdoi:10.1038/s41586-022-04554-y

Abstract Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight 1 . Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories 2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones 3 , showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

ESHRE Guideline: management of women with premature ovarian insufficiency
L Webber, Lisa Webber, Melanie Davies, Richard A. Anderson +4 more
2016· Human Reproduction1.5Kdoi:10.1093/humrep/dew027

STUDY QUESTION: What is the optimal management of women with premature ovarian insufficiency (POI) based on the best available evidence in the literature? SUMMARY ANSWER: The guideline development group (GDG) formulated 99 recommendations answering 31 key questions on the diagnosis and treatment of women with POI. WHAT IS KNOWN ALREADY: NA. STUDY DESIGN, SIZE, DURATION: This guideline was produced by a multidisciplinary group of experts in the field using the methodology of the Manual for ESHRE Guideline Development, including a thorough systematic search of the literature, quality assessment of the included papers up to September 2014 and consensus within the guideline group on all recommendations. The GDG included a patient representative to ensure input from women with POI. After finalization of the draft, the European Society for Human Reproduction and Embryology (ESHRE) members and professional organizations were asked to review the guideline. PARTICIPANTS/MATERIALS, SETTING, METHODS: NA. MAIN RESULTS AND THE ROLE OF CHANCE: The guideline provides 17 recommendations on diagnosis and assessment of POI and 46 recommendations on the different sequelae of POI and their consequences for monitoring and treatment. Furthermore, 24 recommendations were formulated on hormone replacement therapy in women with POI, and two on alternative and complementary treatment. A chapter on puberty induction resulted in five recommendations. LIMITATIONS, REASONS FOR CAUTION: The main limitation of the guideline is that, due to the lack of data, many of the recommendations are based on expert opinion or indirect evidence from studies on post-menopausal women or women with Turner Syndrome. WIDER IMPLICATIONS OF THE FINDINGS: Despite the limitations, the guideline group is confident that this document will be able to guide health care professionals in providing the best practice for managing women with POI given current evidence. Furthermore, the guideline group has formulated research recommendations on the gaps in knowledge identified in the literature searches, in an attempt to stimulate research on the key issues in POI. STUDY FUNDING/COMPETING INTERESTS: The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the implementation of the guideline. The guideline group members did not receive payment. Dr Davies reports non-financial support from Novo Nordisk, outside the submitted work; the other authors had nothing to disclose. TRIAL REGISTRATION NUMBER: NA.

ESHRE guideline: endometriosis
Christian M. Becker, Attila Bokor, Oskari Heikinheimo, Andrew W. Horne +4 more
2022· Human Reproduction Open1.4Kdoi:10.1093/hropen/hoac009

STUDY QUESTION: How should endometriosis be diagnosed and managed based on the best available evidence from published literature? SUMMARY ANSWER: The current guideline provides 109 recommendations on diagnosis, treatments for pain and infertility, management of disease recurrence, asymptomatic or extrapelvic disease, endometriosis in adolescents and postmenopausal women, prevention and the association with cancer. WHAT IS KNOWN ALREADY: Endometriosis is a chronic condition with a plethora of presentations in terms of not only the occurrence of lesions, but also the presence of signs and symptoms. The most important symptoms include pain and infertility. STUDY DESIGN SIZE DURATION: The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 1 December 2020 and written in English were included in the literature review. PARTICIPANTS/MATERIALS SETTING METHODS: Based on the collected evidence, recommendations were formulated and discussed within specialist subgroups and then presented to the core guideline development group (GDG) until consensus was reached. A stakeholder review was organized after finalization of the draft. The final version was approved by the GDG and the ESHRE Executive Committee. MAIN RESULTS AND THE ROLE OF CHANCE: This guideline aims to help clinicians to apply best care for women with endometriosis. Although studies mostly focus on women of reproductive age, the guideline also addresses endometriosis in adolescents and postmenopausal women. The guideline outlines the diagnostic process for endometriosis, which challenges laparoscopy and histology as gold standard diagnostic tests. The options for treatment of endometriosis-associated pain symptoms include analgesics, medical treatments and surgery. Non-pharmacological treatments are also discussed. For management of endometriosis-associated infertility, surgical treatment and/or medically assisted reproduction are feasible. While most of the more recent studies confirm previous ESHRE recommendations, there are five topics in which significant changes to recommendations were required and changes in clinical practice are to be expected. LIMITATIONS REASONS FOR CAUTION: The guideline describes different management options but, based on existing evidence, no firm recommendations could be formulated on the most appropriate treatments. Also, for specific clinical issues, such as asymptomatic endometriosis or extrapelvic endometriosis, the evidence is too scarce to make evidence-based recommendations. WIDER IMPLICATIONS OF THE FINDINGS: The guideline provides clinicians with clear advice on best practice in endometriosis care, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in endometriosis. STUDY FUNDING/COMPETING INTERESTS: The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payments. C.M.B. reports grants from Bayer Healthcare and the European Commission; Participation on a Data Safety Monitoring Board or Advisory Board with ObsEva (Data Safety Monitoring Group) and Myovant (Scientific Advisory Group). A.B. reports grants from FEMaLE executive board member and European Commission Horizon 2020 grant; consulting fees from Ethicon Endo Surgery, Medtronic; honoraria for lectures from Ethicon; and support for meeting attendance from Gedeon Richter; A.H. reports grants from MRC, NIHR, CSO, Roche Diagnostics, Astra Zeneca, Ferring; Consulting fees from Roche Diagnostics, Nordic Pharma, Chugai and Benevolent Al Bio Limited all paid to the institution; a pending patent on Serum endometriosis biomarker; he is also Chair of TSC for STOP-OHSS and CERM trials. O.H. reports consulting fees and speaker's fees from Gedeon Richter and Bayer AG; support for attending meetings from Gedeon-Richter, and leadership roles at the Finnish Society for Obstetrics and Gynecology and the Nordic federation of the societies of obstetrics and gynecology. L.K. reports consulting fees from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; honoraria for lectures from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; support for attending meetings from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; he also has a leadership role in the German Society of Gynecological Endocrinology (DGGEF). M.K. reports grants from French Foundation for Medical Research (FRM), Australian Ministry of Health, Medical Research Future Fund and French National Cancer Institute; support for meeting attendance from European Society for Gynaecological Endoscopy (ESGE), European Congress on Endometriosis (EEC) and ESHRE; She is an advisory Board Member, FEMaLe Project (Finding Endometriosis Using Machine Learning), Scientific Committee Chair for the French Foundation for Research on Endometriosis and Scientific Committee Chair for the ComPaRe-Endometriosis cohort. A.N. reports grants from Merck SA and Ferring; speaker fees from Merck SA and Ferring; support for meeting attendance from Merck SA; Participation on a Data Safety Monitoring Board or Advisory Board with Nordic Pharma and Merck SA; she also is a board member of medical advisory board, Endometriosis Society, the Netherlands (patients advocacy group) and an executive board member of the World Endometriosis Society. E.S. reports grants from National Institute for Health Research UK, Rosetrees Trust, Barts and the London Charity; Royalties from De Gruyter (book editor); consulting fees from Hologic; speakers fees from Hologic, Johnson & Johnson, Medtronic, Intuitive, Olympus and Karl Storz; Participation in the Medicines for Women's Health Expert Advisory Group with Medicines and Healthcare Products Regulatory Agency (MHRA); he is also Ambassador for the World Endometriosis Society. C.T. reports grants from Merck SA; Consulting fees from Gedeon Richter, Nordic Pharma and Merck SA; speaker fees from Merck SA, all paid to the institution; and support for meeting attendance from Ferring, Gedeon Richter and Merck SA. The other authors have no conflicts of interest to declare. DISCLAIMER: www.eshre.eu/guidelines.).

Generation of Reactive Oxygen Species, Lipid Peroxidation, and Human Sperm Function
R. John Aitken, J. S. Clarkson, Simon Fishel
1989· Biology of Reproduction1.2Kdoi:10.1095/biolreprod41.1.183

Recent studies have demonstrated that human spermatozoa are capable of generating reactive oxygen species and that this activity is significantly accelerated in cases of defective sperm function. In view of the pivotal role played by lipid peroxidation in mediating free radical damage to cells, we have examined the relationships between reactive oxygen species production, lipid peroxidation, and the functional competence of human spermatozoa. Using malondialdehyde production in the presence of ferrous ion promoter as an index of lipid peroxidation, we have shown that lipid peroxidation is significantly accelerated in populations of defective spermatozoa exhibiting high levels of reactive oxygen species production or in normal cells stimulated to produce oxygen radicals by the ionophore, A23187. The functional consequences of lipid peroxidation included a dose-dependent reduction in the ability of human spermatozoa to exhibit sperm oocyte-fusion, which could be reversed by the inclusion of a chain-breaking antioxidant, alpha-tocopherol. Low levels of lipid peroxidation also had a slight enhancing effect on the generation of reactive oxygen species in response to ionophore, without influencing the steady-state activity. At higher levels of lipid peroxidation, both the basal level of reactive oxygen species production and the response to A23187 were significantly diminished. In contrast, lipid peroxidation had a highly significant, enhancing effect on the ability of human spermatozoa to bind to both homologous and heterologous zonae pellucidae via mechanisms that could again be reversed by alpha-tocopherol. These results are consistent with a causative role for lipid peroxidation in the etiology of defective sperm function and also suggest a possible physiological role for the reactive oxygen species generated by human spermatozoa in mediating sperm-zona interaction.

Proliferation and functional maturation of Sertoli cells, and their relevance to disorders of testis function in adulthood
RM Sharpe, Chris McKinnell, C Kivlin, JS Fisher
2003· Reproduction1.2Kdoi:10.1530/rep.0.1250769

Abstract Disorders of testicular function may have their origins in fetal or early life as a result of abnormal development or proliferation of Sertoli cells. Failure of Sertoli cells to mature, with consequent inability to express functions capable of supporting spermatogenesis, is a prime example. In a similar way, failure of Sertoli cells to proliferate normally at the appropriate period in life will result in reduced production of spermatozoa in adulthood. This review focuses on the control of proliferation of Sertoli cells and functional maturation, and is motivated by concerns about 'testicular dysgenesis syndrome' in humans, a collection of common disorders (testicular germ-cell cancer, cryptorchidism, hypospadias and low sperm counts) which are hypothesized to have a common origin in fetal life and to reflect abnormal function of Sertoli (and Leydig) cells. The timing of proliferation of Sertoli cells in different species is reviewed, and the factors that govern the conversion of an immature, proliferating Sertoli cell to a mature, non-proliferating cell are discussed. Protein markers of maturity and immaturity of Sertoli cells in various species are reviewed and their usefulness in studies of human testicular pathology are discussed. These markers include anti-Mullerian hormone, aromatase, cytokeratin-18, GATA-1, laminin alpha5, M2A antigen, p27(kip1), sulphated glycoprotein 2, androgen receptor and Wilms' tumour gene. A scheme is presented for characterization of Sertoli-cell only tubules in the adult testis according to whether or not there is inherent failure of maturation of Sertoli cells or in which the Sertoli cells have matured but there is absence, or acquired loss, of germ cells. Functional 'de-differentiation' of Sertoli cells is considered. It is concluded that there is considerable evidence to indicate that disorders of maturation of Sertoli cells may be a common underlying cause of human male reproductive disorders that manifest at various life stages. This recognition emphasizes the important role that animal models must play to enable identification of the mechanisms via which failure of proliferation and maturation of Sertoli cells can arise, as this failure probably occurs in fetal life.

Medical Complications After Stroke
Peter Langhorne, David J. Stott, Laura Robertson, Joel MacDonald +4 more
2000· Stroke1.2Kdoi:10.1161/01.str.31.6.1223

BACKGROUND AND PURPOSE: This prospective, multicenter study was performed to determine the frequency of symptomatic complications up to 30 months after stroke using prespecified definitions of complications. METHODS: We recruited 311 consecutive stroke patients admitted to hospital. Research nurses reviewed their progress on a weekly basis until hospital discharge and again at 6, 18, and 30 months after stroke. RESULTS: Complications during hospital admission were recorded in 265 (85%) of stroke patients. Specific complications were as follows: neurological-recurrent stroke (9% of patients), epileptic seizure (3%); infections-urinary tract infection (24%), chest infection (22%), others (19%); mobility related-falls (25%), falls with serious injury (5%), pressure sores (21%); thromboembolism-deep venous thrombosis (2%), pulmonary embolism (1%); pain-shoulder pain (9%), other pain (34%); and psychological-depression (16%), anxiety (14%), emotionalism (12%), and confusion (56%). During follow-up, infections, falls, "blackouts, " pain, and symptoms of depression and anxiety remained common. Complications were observed across all 3 hospital sites, and their frequency was related to patient dependency and duration after stroke. CONCLUSIONS: Our prospective cohort study has confirmed that poststroke complications, particularly infections and falls, are common. However, we have also identified complications relating to pain and cognitive or affective symptoms that are potentially preventable and may previously have been underestimated.

The physiology and clinical utility of anti-Müllerian hormone in women
Didier Dewailly, Claus Yding Andersen, Adam Balen, Frank J. Broekmans +4 more
2014· Human Reproduction Update1.1Kdoi:10.1093/humupd/dmt062

BACKGROUND The measurement of circulating anti-Müllerian hormone (AMH) has been applied to a wide array of clinical applications, mainly based on its ability to reflect the number of antral and pre-antral follicles present in the ovaries. AMH has been suggested to predict the ovarian response to hyperstimulation of the ovaries for IVF and the timing of menopause, and to indicate iatrogenic damage to the ovarian follicle reserve. It has also been proposed as a surrogate for antral follicle count (AFC) in the diagnosis of polycystic ovary syndrome (PCOS). METHODS This paper is a summary of presentations at a European Society of Human Reproduction and Embryology campus workshop on AMH, with literature cited until September 2013. Published peer-reviewed medical literature about AMH was searched through MEDLINE and was subjected to systematic review and critical assessment by the panel of authors. RESULTS Physiologically, recent data confirm that AMH is a follicular gatekeeper limiting follicle growth initiation, and subsequently estradiol production from small antral follicles prior to selection. AMH assays continue to evolve and technical issues remain; the absence of an international standard is a key issue. The dynamics of circulating AMH levels throughout life can be split into several distinct phases, with a peak in the early 20s before a decline to the menopause, with a strong and positive correlation with non-growing follicle recruitment. There is a more complex rise during childhood and adolescence, which is likely to be more reflective of different stages of follicle development. AMH shows limited short-term variability, but the influence of states such as prolonged oral contraceptive use need to be considered in clinical assessment. There are only very limited data on relationships between AMH and natural fertility at different stages of reproductive life, and while it has a relationship to age at menopause the marked variability in this needs further exploration. AMH may be useful in assessing the need for fertility preservation strategies and detecting post-chemotherapy or surgical damage to the ovarian reserve. Long-term follow-up of patients to ascertain fully the value of post-cancer serum AMH in predicting long-term ovarian function is required. There is a linear relationship between AMH and oocyte yield after ovarian stimulation, which is of value in predicting ovarian hyperstimulation. AMH can also identify 'poor responders', but it seems inappropriate at present to withhold IVF purely on this basis. Women with PCOS show markedly raised AMH levels, due to both the increased number of small antral follicles and intrinsic characteristics of those granulosa cells, and this may contribute to anovulation. The value of AMH in the diagnosis of PCOS remains controversial, but it may replace AFC in the future. CONCLUSIONS For the first time in female reproductive biology, it is possible to measure the submerged part of the iceberg of follicle growth, i.e. the intrinsic, so-called 'acyclic' ovarian activity. An international standard for AMH and improved assay validity are urgently needed to maximize the clinical utility of this very promising biomarker of ovarian function in a large array of clinical situations, both in childhood and adulthood.

Cellular basis of defective sperm function and its association with the genesis of reactive oxygen species by human spermatozoa
R. John Aitken, J. S. Clarkson
1987· Reproduction1.0Kdoi:10.1530/jrf.0.0810459

Addition of the divalent cation ionophore, A23187, to washed populations of human spermatozoa resulted in a sudden burst of production of reactive oxygen species which peaked within 3-5 min. This activity was dependent upon the presence of calcium in the external medium and was unaffected by the mitochondrial inhibitors, oligomycin, antimycin and rotenone. Studies with scavengers of reactive oxygen species revealed that, while reagents directed against singlet oxygen and the hydroxyl radical were without effect, cytochrome C reduced the response to A23187 by about 50%, suggesting that the superoxide anion radical is a major product of the activated human spermatozoon. The clinical implications of these studies stem from the considerable variation observed between individuals in the levels of reactive oxygen species produced by the spermatozoa. This variability was shown to be inversely related to the ability of the spermatozoa to exhibit sperm-oocyte fusion on exposure to A23187; defective samples exhibited a basal level of reactive oxygen species production which was 40 times that observed with normal functional cells.

The two FIGO systems for normal and abnormal uterine bleeding symptoms and classification of causes of abnormal uterine bleeding in the reproductive years: 2018 revisions
Malcolm G. Munro, Hilary Critchley, Ian S. Fraser
2018· International Journal of Gynecology & Obstetrics954doi:10.1002/ijgo.12666

BACKGROUND: The International Federation of Gynecology and Obstetrics (FIGO) systems for nomenclature of symptoms of normal and abnormal uterine bleeding (AUB) in the reproductive years (FIGO AUB System 1) and for classification of causes of AUB (FIGO AUB System 2; PALM-COEIN) were first published together in 2011. The purpose was to harmonize the definitions of normal and abnormal bleeding symptoms and to classify and subclassify underlying potential causes of AUB in the reproductive years to facilitate research, education, and clinical care. The systems were designed to be flexible and to be periodically reviewed and modified as appropriate. OBJECTIVES: To review, clarify, and, where appropriate, revise the previously published systems. METHODOLOGY AND OUTCOME: To a large extent, the process has been an iterative one involving the FIGO Menstrual Disorders Committee, as well as a number of invited contributions from epidemiologists, gynecologists, and other experts in the field from around the world between 2012 and 2017. Face-to-face meetings have been held in Rome, Vancouver, and Singapore, and have been augmented by a number of teleconferences and other communications designed to evaluate various aspects of the systems. Where substantial change was considered, anonymous voting, in some instances using a modified RAND Delphi technique, was utilized.

Human Tumor-Associated Macrophage and Monocyte Transcriptional Landscapes Reveal Cancer-Specific Reprogramming, Biomarkers, and Therapeutic Targets
Luca Cassetta, Stamatina Fragkogianni, Andrew H. Sims, Agnieszka Swierczak +4 more
2019· Cancer Cell948doi:10.1016/j.ccell.2019.02.009

The roles of tumor-associated macrophages (TAMs) and circulating monocytes in human cancer are poorly understood. Here, we show that monocyte subpopulation distribution and transcriptomes are significantly altered by the presence of endometrial and breast cancer. Furthermore, TAMs from endometrial and breast cancers are transcriptionally distinct from monocytes and their respective tissue-resident macrophages. We identified a breast TAM signature that is highly enriched in aggressive breast cancer subtypes and associated with shorter disease-specific survival. We also identified an auto-regulatory loop between TAMs and cancer cells driven by tumor necrosis factor alpha involving SIGLEC1 and CCL8, which is self-reinforcing through the production of CSF1. Together these data provide direct evidence that monocyte and macrophage transcriptional landscapes are perturbed by cancer, reflecting patient outcomes.

Long-term risks and benefits associated with cesarean delivery for mother, baby, and subsequent pregnancies: Systematic review and meta-analysis
Oonagh Keag, Jane E. Norman, Sarah J. Stock
2018· PLoS Medicine895doi:10.1371/journal.pmed.1002494

BACKGROUND: Cesarean birth rates continue to rise worldwide with recent (2016) reported rates of 24.5% in Western Europe, 32% in North America, and 41% in South America. The objective of this systematic review is to describe the long-term risks and benefits of cesarean delivery for mother, baby, and subsequent pregnancies. The primary maternal outcome was pelvic floor dysfunction, the primary baby outcome was asthma, and the primary subsequent pregnancy outcome was perinatal death. METHODS AND FINDINGS: Medline, Embase, Cochrane, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were systematically searched for published studies in human subjects (last search 25 May 2017), supplemented by manual searches. Included studies were randomized controlled trials (RCTs) and large (more than 1,000 participants) prospective cohort studies with greater than or equal to one-year follow-up comparing outcomes of women delivering by cesarean delivery and by vaginal delivery. Two assessors screened 30,327 abstracts. Studies were graded for risk of bias by two assessors using the Scottish Intercollegiate Guideline Network (SIGN) Methodology Checklist and the Risk of Bias Assessment tool for Non-Randomized Studies. Results were pooled in fixed effects meta-analyses or in random effects models when significant heterogeneity was present (I2 ≥ 40%). One RCT and 79 cohort studies (all from high income countries) were included, involving 29,928,274 participants. Compared to vaginal delivery, cesarean delivery was associated with decreased risk of urinary incontinence, odds ratio (OR) 0.56 (95% CI 0.47 to 0.66; n = 58,900; 8 studies) and pelvic organ prolapse (OR 0.29, 0.17 to 0.51; n = 39,208; 2 studies). Children delivered by cesarean delivery had increased risk of asthma up to the age of 12 years (OR 1.21, 1.11 to 1.32; n = 887,960; 13 studies) and obesity up to the age of 5 years (OR 1.59, 1.33 to 1.90; n = 64,113; 6 studies). Pregnancy after cesarean delivery was associated with increased risk of miscarriage (OR 1.17, 1.03 to 1.32; n = 151,412; 4 studies) and stillbirth (OR 1.27, 1.15 to 1.40; n = 703,562; 8 studies), but not perinatal mortality (OR 1.11, 0.89 to 1.39; n = 91,429; 2 studies). Pregnancy following cesarean delivery was associated with increased risk of placenta previa (OR 1.74, 1.62 to 1.87; n = 7,101,692; 10 studies), placenta accreta (OR 2.95, 1.32 to 6.60; n = 705,108; 3 studies), and placental abruption (OR 1.38, 1.27 to 1.49; n = 5,667,160; 6 studies). This is a comprehensive review adhering to a registered protocol, and guidelines for the Meta-analysis of Observational Studies in Epidemiology were followed, but it is based on predominantly observational data, and in some meta-analyses, between-study heterogeneity is high; therefore, causation cannot be inferred and the results should be interpreted with caution. CONCLUSIONS: When compared with vaginal delivery, cesarean delivery is associated with a reduced rate of urinary incontinence and pelvic organ prolapse, but this should be weighed against the association with increased risks for fertility, future pregnancy, and long-term childhood outcomes. This information could be valuable in counselling women on mode of delivery.

Human Ovarian Reserve from Conception to the Menopause
William H. Wallace, Tom Kelsey
2010· PLoS ONE856doi:10.1371/journal.pone.0008772

The human ovary contains a fixed number of non-growing follicles (NGFs) established before birth that decline with increasing age culminating in the menopause at 50-51 years. The objective of this study is to model the age-related population of NGFs in the human ovary from conception to menopause. Data were taken from eight separate quantitative histological studies (n = 325) in which NGF populations at known ages from seven weeks post conception to 51 years (median 32 years) were calculated. The data set was fitted to 20 peak function models, with the results ranked by obtained r2 correlation coefficient. The highest ranked model was chosen. Our model matches the log-adjusted NGF population from conception to menopause to a five-parameter asymmetric double Gaussian cumulative (ADC) curve (r2 = 0.81). When restricted to ages up to 25 years, the ADC curve has r2 = 0.95. We estimate that for 95% of women by the age of 30 years only 12% of their maximum pre-birth NGF population is present and by the age of 40 years only 3% remains. Furthermore, we found that the rate of NGF recruitment towards maturation for most women increases from birth until approximately age 14 years then decreases towards the menopause. To our knowledge, this is the first model of ovarian reserve from conception to menopause. This model allows us to estimate the number of NGFs present in the ovary at any given age, suggests that 81% of the variance in NGF populations is due to age alone, and shows for the first time, to our knowledge, that the rate of NGF recruitment increases from birth to age 14 years then declines with age until menopause. An increased understanding of the dynamics of human ovarian reserve will provide a more scientific basis for fertility counselling for both healthy women and those who have survived gonadotoxic cancer treatments.

Relative Impact of Oxidative Stress on the Functional Competence and Genomic Integrity of Human Spermatozoa1
R. John Aitken, Emma Gordon, Diana Harkiss, Jeremy Twigg +3 more
1998· Biology of Reproduction788doi:10.1095/biolreprod59.5.1037

Reactive oxygen metabolites are known to disrupt sperm-oocyte fusion, sperm movement, and DNA integrity; however, the relative sensitivities of these elements to oxidative stress are unknown. In this study these factors were assessed in human spermatozoa exposed to increasing levels of oxidative stress achieved through the stimulation of endogenous oxidant generation with NADPH or direct exposure to hydrogen peroxide. At low levels of oxidative stress, DNA fragmentation was significantly reduced while the rates of sperm-oocyte fusion were significantly enhanced. As the level of oxidative stress increased, the spermatozoa exhibited significantly elevated levels of DNA damage (p < 0.001) and yet continued to express an enhanced capacity for sperm-oocyte fusion. At the highest levels of oxidative stress, extremely high rates of DNA fragmentation were observed but the spermatozoa exhibited a parallel loss in their capacities for movement and oocyte fusion. These studies emphasize how redox mechanisms can either enhance or disrupt the functional and genomic integrity of human spermatozoa depending on the intensity of the oxidative stimulus. Because these qualities are affected at different rates, spermatozoa exhibiting significant DNA damage are still capable of fertilizing the oocyte. These results may have long-term implications for the safety of assisted conception procedures in cases associated with oxidative stress.

Restoration of fertility to oophorectomized sheep by ovarian autografts stored at-196°C
Roger G. Gosden, David T. Baird, J.C. Wade, R. Webb
1994· Human Reproduction787doi:10.1093/oxfordjournals.humrep.a138556

Cortical slices were prepared from the right ovaries of six lambs and either grafted directly to the ovarian pedicles of origin or cooled slowly to liquid nitrogen temperatures in medium containing dimethylsulphoxide. Three weeks later, the contra-lateral ovary was removed and replaced with frozen-thawed slices from the same animal. Two of the animals mated during their second oestrous cycle 3-4 months later and the remainder had at least one ovulatory cycle. The pregnancies reached full-term development, one lamb being derived from an ovulation in a fresh graft and the other from a frozen-thawed graft. None of the sheep had peripheral plasma concentrations of follicle stimulating hormone or luteinizing hormone consistently in the castrate range, and only one graft was devoid of follicles when the animals were slaughtered 9 months after the operations. Grafts with primordial follicles always contained developing follicles, which occasionally attained pre-ovulatory sizes of 7 mm in diameter. A corpus albicans was present in five grafts. Since all developing follicles had degenerated 1 week after grafting in an additional ewe, the large follicles in long-term grafts had presumably commenced growing after the operation. There were no obvious differences between fresh and frozen-thawed grafts in either appearance or weight, and all had apparently grown since implantation. Despite substantial depletion of primordial follicle numbers, the results indicated that frozen storage and replacement of a patient's own ovarian tissue might be practicable when fertility potential is threatened by chemotherapy/radiotherapy.

Gonadotropin-Releasing Hormone Receptors
Robert P. Millar, Zhi-Liang Lu, Adam J Pawson, Colleen A. Flanagan +2 more
2004· Endocrine Reviews781doi:10.1210/er.2003-0002

GnRH and its analogs are used extensively for the treatment of hormone-dependent diseases and assisted reproductive techniques. They also have potential as novel contraceptives in men and women. A thorough delineation of the molecular mechanisms involved in ligand binding, receptor activation, and intracellular signal transduction is kernel to understanding disease processes and the development of specific interventions. Twenty-three structural variants of GnRH have been identified in protochordates and vertebrates. In many vertebrates, three GnRHs and three cognate receptors have been identified with distinct distributions and functions. In man, the hypothalamic GnRH regulates gonadotropin secretion through the pituitary GnRH type I receptor via activation of G q . In-depth studies have identified amino acid residues in both the ligand and receptor involved in binding, receptor activation, and translation into intracellular signal transduction. Although the predominant coupling of the type I GnRH receptor in the gonadotrope is through productive G q stimulation, signal transduction can occur via other G proteins and potentially by G protein-independent means. The eventual selection of intracellular signaling may be specifically directed by variations in ligand structure. A second form of GnRH, GnRH II, conserved in all higher vertebrates, including man, is present in extrahypothalamic brain and many reproductive tissues. Its cognate receptor has been cloned from various vertebrate species, including New and Old World primates. The human gene homolog of this receptor, however, has a frame-shift and stop codon, and it appears that GnRH II signaling occurs through the type I GnRH receptor. There has been considerable plasticity in the use of different GnRHs, receptors, and signaling pathways for diverse functions. Delineation of the structural elements in GnRH and the receptor, which facilitate differential signaling, will contribute to the development of novel interventive GnRH analogs. (Endocrine Reviews 25: 235-275, 2004) I. Introduction II. Structure of GnRHs and Analogs A. Structural variants of GnRHs B. Structure of GnRH and peptide analogs C. The evolutionarily conserved GnRH II D. Nonpeptide GnRH antagonists III. Structure of GnRH Receptors A. Primary structures of GnRH receptors B. Tertiary structure of the mammalian type I GnRH receptor IV. Binding of GnRH to the Mammalian Type I GnRH Receptor A. Aspartate 2. 61(98) [D 2.61(98) ] B. Asparagine 2.65(102) [N 2.65(102) ] C. Lysine 3.32(121) [K 3.32(121) ] D. Asparagine 5.39(212) [N 5.39(212) ] E. Tyrosine 6.58(290) [Y 6.58(290) ] F. Aspartate 7.32(302) [D 7.32(302) ] G. Effects of mutations of other residues on the ligand binding pocket H. Ligand docking to the receptor V. Binding Interactions of Other GnRH Ligands and Other Receptors A. GnRH II B. Peptide agonists C. Peptide antagonists D. Nonpeptide antagonists E. Binding sites in nonmammalian type I GnRH receptors F. Binding sites in type II receptors G. Utilization of binding sites common to the rhodopsin family of GPCRs VI. Receptor Activation A. Interaction of Asn 2.50(87) /Asp 7.49(319) in TM 2/7 in GnRH receptor activation B. Disruption of TM3 Asp 3.49(138) /Arg 3.50(139) interaction in GnRH receptor activation C. The triad of Glu 2.53(90) -Lys 3.32(121) -Asp 2.61(98) D. Role of extracellular loop 2 E. Other residues possibly involved in receptor activation F. Integrated model of GnRH receptor activation VII. GnRH Receptor Mutations in Hypogonadotropic Hypogonadism VIII. Structural Correlates of GnRH Receptor Coupling and Internalization A. Coupling to multiple G proteins B. Regulators of G protein signaling (RGS) proteins C. GnRH receptor internalization IX.

Significance of Reactive Oxygen Species and Antioxidants in Defining the Efficacy of Sperm Preparation Techniques
R. John Aitken, J. S. Clarkson
1988· Journal of Andrology779doi:10.1002/j.1939-4640.1988.tb01067.x

The mechanisms responsible for mediating the influence of sperm preparation protocols on human sperm function have been investigated. Techniques that involved the separation of motile spermatozoa prior to centrifugation were found to yield sperm suspensions of highest quality. If the spermatozoa were centrifuged prior to isolation of the motile cells, sperm function was impaired. The detrimental effects of centrifugation were associated with a sudden burst of reactive oxygen species production by a discrete subpopulation of cells (characterized by significantly diminished motility and fertilizing capacity) that could be separated from normal functional spermatozoa on Percoll gradients. If unfractionated sperm suspensions were subjected to centrifugation, the reactive oxygen species generated by this subpopulation impaired the functional competence of normal spermatozoa in the same suspension. Assessment of the ability of the antioxidants, butylated hydroxytoluene, and vitamin E, to curtail the peroxidative damage inflicted by such cells in response to centrifugation revealed a significant improvement of sperm function in the presence of vitamin E.

Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism
Michelle Welsh, Philippa T. K. Saunders, M. Fisken, Hayley M Scott +3 more
2008· Journal of Clinical Investigation771doi:10.1172/jci34241

Becoming a phenotypic male is ultimately determined by androgen-induced masculinization. Disorders of fetal masculinization, resulting in hypospadias or cryptorchidism, are common, but their cause remains unclear. Together with the adult-onset disorders low sperm count and testicular cancer, they can constitute a testicular dysgenesis syndrome (TDS). Although masculinization is well studied, no unifying concept explains normal male reproductive development and its abnormalities, including TDS. We exposed rat fetuses to either anti-androgens or androgens and showed that masculinization of all reproductive tract tissues was programmed by androgen action during a common fetal programming window. This preceded morphological differentiation, when androgen action was, surprisingly, unnecessary. Only within the programming window did blocking androgen action induce hypospadias and cryptorchidism and altered penile length in male rats, all of which correlated with anogenital distance (AGD). Androgen-driven masculinization of females was also confined to the same programming window. This work has identified in rats a common programming window in which androgen action is essential for normal reproductive tract masculinization and has highlighted that measuring AGD in neonatal humans could provide a noninvasive method to predict neonatal and adult reproductive disorders. Based on the timings in rats, we believe the programming window in humans is likely to be 8-14 weeks of gestation.

DNA Integrity in Human Spermatozoa: Relationships With Semen Quality
D. Stewart Irvine, Jeremy Twigg, EMMA L. GORDON, Norma Fulton +2 more
2000· Journal of Andrology738doi:10.1002/j.1939-4640.2000.tb03273.x

The literature contains conflicting evidence regarding the existence of DNA damage in spermatozoa from infertile male patients. To examine this phenomenon, we have studied ejaculated spermatozoa from normozoospermic semen donors and from a group of the unselected male partners of couples attending an infertility clinic for initial investigation. Classical semen analysis according to World Health Organization (WHO) guidelines was undertaken with computer-assisted sperm analysis (CASA). Spermatozoa were prepared by sequential washing and centrifugation and were analyzed for DNA fragmentation using three assays: 1) a single-cell gel electrophoresis (comet) assay, 2) in situ nick translation with prior chemical decondensation (ISNT-decondensed), and 3) in situ nick translation without prior chemical decondensation (ISNT-condensed). In addition, reactive oxygen species (ROS) generation by spermatozoa was measured, and seminal plasma was analyzed for its total reactive antioxidant potential (TRAP). When the donor and patient groups were compared, the latter had lower levels of semen quality and higher levels of DNA damage, which was particularly apparent using the comet assay. Highly significant negative correlations were observed between DNA fragmentation, detected by all three assays, and semen quality, particularly sperm concentration. In addition, multiple regression analysis indicated that other attributes of semen quality, such as sperm movement and ROS generation, were also related to DNA damage. We conclude that a significant proportion of infertile men have elevated levels of DNA damage in their ejaculated spermatozoa.

Effect of Body Mass Index on pregnancy outcomes in nulliparous women delivering singleton babies
Sohinee Bhattacharya, Doris M. Campbell, William A. Liston, Siladitya Bhattacharya
2007· BMC Public Health689doi:10.1186/1471-2458-7-168

BACKGROUND: The increasing prevalence of obesity in young women is a major public health concern. These trends have a major impact on pregnancy outcomes in these women, which have been documented by several researchers. In a population based cohort study, using routinely collected data, this paper examines the effect of increasing Body Mass Index (BMI) on pregnancy outcomes in nulliparous women delivering singleton babies. METHODS: This was a retrospective cohort study, based on all nulliparous women delivering singleton babies in Aberdeen between 1976 and 2005. Women were categorized into five groups--underweight (BMI < 20 Kg/m2), normal (BMI 20-24.9 Kg/m2) overweight (BMI 25-29.9 Kg/m2), obese (BMI 30-34.9 Kg/m2) and morbidly obese (BMI > 35 Kg/m2). Obstetric and perinatal outcomes were compared by univariate and multivariate analyses. RESULTS: In comparison with women of BMI 20-24.9, morbidly obese women faced the highest risk of pre-eclampsia {OR 7.2 (95% CI 4.7, 11.2)} and underweight women the lowest {OR 0.6 (95% CI 0.5, 0.7)}. Induced labour was highest in the morbidly obese {OR 1.8 (95% CI 1.3, 2.5)} and lowest in underweight women {OR 0.8 (95% CI 0.8, 0.9)}. Emergency Caesarean section rates were highest in the morbidly obese {OR 2.8 (95% CI 2.0, 3.9)}, and comparable in women with normal and low BMI. Obese women were more likely to have postpartum haemorrhage {OR 1.5 (95% CI 1.3, 1.7)} and preterm delivery (< 33 weeks) {OR 2.0 (95% CI 1.3, 2.9)}. Birthweights less than 2,500 g were more common in underweight women {OR 1.7 (95% OR 1.2, 2.0)}. The highest risk of birth weights > 4,000 g was in the morbidly obese {OR 2.1 (95% CI 1.3, 3.2)} and the lowest in underweight women {OR 0.5 (95% CI 0.4, 0.6)}. CONCLUSION: Increasing BMI is associated with increased incidence of pre-eclampsia, gestational hypertension, macrosomia, induction of labour and caesarean delivery; while underweight women had better pregnancy outcomes than women with normal BMI.