Multiple gestation associated with infertility therapy: a committee opinion.

This Committee Opinion provides practitioners with suggestions to reduce the likelihood of iatrogenic multiple gestation resulting from infertility treatment. This document replaces the document of the same name previously published in 2012 (Fertil Steril 2012;97:825-34 by the American Society for Reproductive Medicine).

Optimizing natural fertility: a committee opinion.

This committee opinion provides practitioners with suggestions for optimizing the likelihood of achieving pregnancy in couples or individuals attempting conception who have no evidence of infertility. This document replaces the document of the same name previously published in 2013 (Fertil Steril 2013;100:631-7).

Teaming for excellence: challenges and collaboration in the world of reproductive clinical and translational research.

To succeed in the conduct of clinical trials in reproductive medicine, teams must be trained and cultivated to collaborate and achieve a common goal. Here I share my personal experiences and lessons learned in teaming in the research setting by covering topics in time management, resource allocation, collaboration, publishing, and communication.

Guidance on the limits to the number of embryos to transfer: a committee opinion.

On the basis of American Society for Reproductive Medicine and Society for Assisted Reproductive Technology data, the American Society for Reproductive Medicine's guidelines for the limits on the number of embryos to be transferred during in vitro fertilization cycles have been further refined in continuing efforts to promote singleton gestation and reduce the number of multiple pregnancies. This version replaces the document titled "Criteria for number of embryos to transfer: a committee opinion" that was published most recently in August of 2017 (Fertil Steril 2017;107:901-3).

Evidence-based outcomes after oocyte cryopreservation for donor oocyte in vitro fertilization and planned oocyte cryopreservation: a guideline.

OBJECTIVE: To provide evidence-based recommendations to practicing physicians and others regarding the efficacy of oocyte cryopreservation (OC) for donor oocyte in vitro fertilization and planned OC. METHODS: The American Society for Reproductive Medicine conducted a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1986 to 2018. The American Society for Reproductive Medicine Practice Committee and a task force of experts used available evidence and through consensus developed evidence-based guideline recommendations. MAIN OUTCOME MEASURE(S): Outcomes of interest included live birth rate, clinical pregnancy rate, obstetrical and neonatal outcomes, and factors predicting reproductive outcomes. RESULT(S): The literature search identified 30 relevant studies to inform the evidence base for this guideline. RECOMMENDATION(S): Evidence-based recommendations were developed for predicting the likelihood of live births after planned OC, autologous OC in infertile women, and donor OC, as well as factors that may impact live birth rates. Recommendations were developed regarding neonatal outcomes after using fresh vs. cryopreserved oocytes in cases of autologous or donor oocytes. CONCLUSION(S): There is insufficient evidence to predict live birth rates after planned OC. On the basis of limited data, ongoing and live birth rates appear to be improved for women who undergo planned OC at a younger vs. older age. Although there are no significant differences in per transfer pregnancy rates with cryopreserved vs. fresh donor oocytes, there is insufficient evidence that the live birth rate is the same with vitrified vs. fresh donor oocytes. Neonatal outcomes appear similar with cryopreserved oocytes compared with fresh oocytes. Future studies that compare cumulative live birth rates are needed.

Guidance for using text, email, and video communication in practices devoted to reproductive medicine.

The prevalence and ease of electronic communication, specifically email through patient portals associated with electronic medical records or via traditional enterprise email clients (e.g., Outlook) and video, have resulted in increased use for rapid communication between practitioners and their patients. Concerns regarding patient privacy and compliance with the regulations of the Health Insurance Portability and Accountability Act (HIPAA) remain a barrier to routine incorporation of electronic communication into practice. Furthermore, capital investment, implementation, and maintenance costs may provide additional barriers. These long-standing concerns have been heightened and tested by the COVID-19 pandemic. Best-practice guidelines for the secure and safe use of electronic communication with reproductive care patients are provided.

Diagnosis and treatment of luteal phase deficiency: a committee opinion.

Luteal phase deficiency (LPD) is a clinical diagnosis associated with an abnormal luteal phase length of ≤10 days. Potential etiologies of LPD include inadequate progesterone duration, inadequate progesterone levels, or endometrial progesterone resistance. LPD has not only been described in association with medical conditions but also in fertile, normally menstruating women. Although progesterone is important for the process of implantation and early embryonic development, LPD has not been proven to be an independent entity causing infertility or recurrent pregnancy loss. Controversy exists regarding the multiple proposed measures for diagnosing LPD and, assuming it can be diagnosed accurately, whether treatment improves outcomes. This document replaces the document entitled "Current clinical irrelevance of luteal phase deficiency: a committee opinion," last published in 2015 (Fertil Steril 2015;103:e27-e32).

Guidance regarding gamete and embryo donation.

This document provides the latest recommendations for the evaluation of potential sperm, oocyte, and embryo donors as well as their recipients, incorporating recent information about optimal screening and testing for sexually transmitted infections, genetic diseases, and psychological assessments. This revised document incorporates recent information from the US Centers for Disease Control and Prevention, US Food and Drug Administration, and American Association of Tissue Banks, which all programs offering gamete and embryo donation services must be thoroughly familiar with, and replaces the document titled "Recommendations for gamete and embryo donation: a committee opinion," last published in 2013.

Guidance on qualifications for fertility counselors: a committee opinion.

This guidance document was developed by the Mental Health Professional Group (MHPG) in partnership with the Practice Committee of the American Society for Reproductive Medicine (ASRM) to help determine the qualifications and training of mental health professionals working in reproductive medicine. This document replaces the document titled "ASRM Qualification Guidelines for Infertility," last published in March 2015 and originally developed in 1995.

We are here for you: infertility clinic communication during the first wave of the COVID-19 pandemic.

PURPOSE: To study how SART-member fertility clinics communicated via clinic websites during the first wave of the COVID-19 pandemic following publication of ASRM COVID-19 Task Force recommendations. METHODS: SART-member fertility clinic websites were systematically surveyed for the presence of an REI-specific COVID-19 message (REI-CM) and analyzed for their adherence to ASRM guidance. RESULTS: Of the 381 active clinic websites, 249 (65.3%) had REI-specific COVID messaging. The presence of REI-CM was more common in private than in academic practices (73% vs 38%, p < 0.001) and with increasing practice volume: 38% of clinics with < 200 annual cycles vs 91% of clinics with > 1000 cycles (p < 0.001). Adherence to ASRM guidance was more common in academic than in private practices (54% vs 31%, p = 0.02). Additionally, 9% of REI-CM (n = 23) announced continued treatment regardless of a patient's clinical urgency. This messaging was more common in groups doing > 1000 cycles a year (18%, p = 0.009). Clinics treating all-comers were less likely to cite ASRM than other clinics (41% vs 62%, p = 0.045). However, 75% (n = 14) cited COVID-19 guidance from WHO, CDC, and state and local governments. CONCLUSIONS: Clinic response to ASRM recommendations during the first wave of COVID-19 pandemic was heterogeneous. Although academic practices were more likely to follow ASRM guidance, there was a lower extent of patient-facing messaging among academic practices than private clinics. In event of further escalations of this and future pandemics, clinics can learn from experiences to provide clear messaging to patients.

Scanning Probe Microscopies: Imaging and Biomechanics in Reproductive Medicine Research.

Basic and translational research in reproductive medicine can provide new insights with the application of scanning probe microscopies, such as atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM). These microscopies, which provide images with spatial resolution well beyond the optical resolution limit, enable users to achieve detailed descriptions of cell topography, inner cellular structure organization, and arrangements of single or cluster membrane proteins. A peculiar characteristic of AFM operating in force spectroscopy mode is its inherent ability to measure the interaction forces between single proteins or cells, and to quantify the mechanical properties (i.e., elasticity, viscoelasticity, and viscosity) of cells and tissues. The knowledge of the cell ultrastructure, the macromolecule organization, the protein dynamics, the investigation of biological interaction forces, and the quantification of biomechanical features can be essential clues for identifying the molecular mechanisms that govern responses in living cells. This review highlights the main findings achieved by the use of AFM and SNOM in assisted reproductive research, such as the description of gamete morphology; the quantification of mechanical properties of gametes; the role of forces in embryo development; the significance of investigating single-molecule interaction forces; the characterization of disorders of the reproductive system; and the visualization of molecular organization. New perspectives of analysis opened up by applying these techniques and the translational impacts on reproductive medicine are discussed.

Guidance on the use of social media in reproductive medicine practice.

The term "social media" refers to computer-mediated technologies that enable individuals and communities to gather, communicate, network, and share information. These technologies represent useful tools for enabling individual providers and their clinics to broadcast content that educates, informs, advertises, and narrates content to a larger audience. There are multiple benefits to maintaining a presence on social media, either as an individual physician or as a clinic, but several pitfalls deserve consideration as well. This guidance document does not endorse any specific cloud-based platform or service, though some are mentioned for the purposes of illustration.

Simulation training for embryo transfer: findings from the American Society for Reproductive Medicine Embryo Transfer Certificate Course.

OBJECTIVE: To assess the value of the American Society for Reproductive Medicine Embryo Transfer Certificate Course in confidence and skill building for performing a live embryo transfer (ET). DESIGN: Prospective cohort study. SETTING: Two-day simulation workshops of reproductive endocrine and infertility (REI) fellows from American Board of Obstetrics and Gynecology-approved training programs, using four different uterine models (A-D). PATIENT(S): None. INTERVENTION(S): Didactic and hands-on simulation training program. MAIN OUTCOME MEASURE(S): Primary outcomes included ET simulation scores of all exercises analyzed at various points of the training and self-assessed confidence before and after the completion of the Embryo Transfer Certificate Course based on a 6-point Likert scale and association of both with extent of prior live ET experience and year of fellowship. RESULT(S): Data were collected for 78 REI fellows who completed the Embryo Transfer Certificate Course and demonstrated significant improvements in both skill and confidence. The data for a subset of 58 fellows who performed five direct transfers on both Embryo Transfer Certificate Course uterine models A and B demonstrated significant overall improvement in ET simulation scores between the first and fifth direct transfers. A separate data subset of 57 fellows who performed five afterload transfers for each exercise on all four uterine models demonstrated differences in difficulty among them. Embryo transfer simulation using the uterine A model was consistently the easiest. The ET simulation scores for fellows using the uterine B and C models showed a progressive and significant increase across the five afterload ETs. When using the uterine D model, ET simulation scores increased significantly between the first and second transfers but remained at the same level for the remaining three transfers. Except for uterus A, a significant increase in ET simulation scores between the first and last transfers was observed for fellows overall in all afterload transfers and for those fellows with <50 prior live transfers. Data for all 78 fellows demonstrate a significant gain of self-confidence for all parameters, with the highest overall increase (78%) observed for first-year fellows as well as for fellows of any year with no prior live transfer experience (109%). Fellows with the largest number of prior live ET experience started with higher confidence, which also increased significantly, although they had a lower gain in confidence compared with fellows with less experience. CONCLUSION(S): The American Society for Reproductive Medicine Embryo Transfer Certificate Course data analysis demonstrates the effectiveness of simulator-based ET training for REI fellows across the 3 years of training, regardless of prior experience with live ET.

Update on PCOS: Consequences, Challenges, and Guiding Treatment.

Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine disorders in women and despite this, diagnostic challenges, delayed diagnosis, and less-than-optimal treatment regimens plague the condition. The International PCOS network, consisting of geographically diverse international experts in PCOS as well as consumers, engaged in a multi-year international evidence-based guideline development process that was jointly sponsored by the European Society for Human Reproduction and Embryology (ESHRE) and the American Society of Reproductive Medicine (ASRM). The guideline was published in 2018 and endorsed by more than 40 international societies involved in PCOS. Translation of this evidence-based guideline to medical practice and consumer groups remains a priority. However, there remain many challenges to both understanding the diagnosis and treatment of PCOS. Evidence suggests that both clinicians and consumers are not satisfied with the timeliness of diagnosis and treatment options. This review summarizes the important findings for diagnosis and treatment from the guidelines and expands on recent developments in the literature since its publication. Special attention to diagnosis at the ends of the reproductive spectrum are discussed and remaining areas of controversy are noted. Additionally, the review highlights some of the remaining challenges in the understanding and management of PCOS to help guide clinicians and investigators in this perplexing condition.

Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline Part I.

PURPOSE: The summary presented herein represents Part I of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part I outlines the appropriate evaluation of the male in an infertile couple. Recommendations proceed from obtaining an appropriate history and physical exam (Appendix I), as well as diagnostic testing, where indicated. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January, 2000 through May, 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table 1[Table: see text]). This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding evaluation of male infertility as well as the association of male infertility with other important health conditions. The detection of male infertility increases the risk of subsequent development of health problems for men. In addition, specific medical conditions are associated with some causes for male infertility. Evaluation and treatment recommendations are summarized in the associated algorithm (figure[Figure: see text]). CONCLUSION: The presence of male infertility is crucial to the health of patients and its effects must be considered for the welfare of society. This document will undergo updating as the knowledge regarding current treatments and future treatment options continues to expand.

Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline PART II.

PURPOSE: The summary presented herein represents Part II of the two-part series dedicated to the Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline. Part II outlines the appropriate management of the male in an infertile couple. Medical therapies, surgical techniques, as well as use of intrauterine insemination (IUI)/in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) are covered to allow for optimal patient management. Please refer to Part I for discussion on evaluation of the infertile male and discussion of relevant health conditions that are associated with male infertility. MATERIALS/METHODS: The Emergency Care Research Institute Evidence-based Practice Center team searched PubMed®, Embase®, and Medline from January 2000 through May 2019. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table[Table: see text]). This summary is being simultaneously published in Fertility and Sterility and The Journal of Urology. RESULTS: This Guideline provides updated, evidence-based recommendations regarding management of male infertility. Such recommendations are summarized in the associated algorithm (figure[Figure: see text]). CONCLUSION: Male contributions to infertility are prevalent, and specific treatment as well as assisted reproductive techniques are effective at managing male infertility. This document will undergo additional literature reviews and updating as the knowledge regarding current treatments and future treatment options continues to expand.

Top 10 priorities for future infertility research: an international consensus development study.

STUDY QUESTION: Can the priorities for future research in infertility be identified? SUMMARY ANSWER: The top 10 research priorities for the four areas of male infertility, female and unexplained infertility, medically assisted reproduction, and ethics, access, and organization of care for people with fertility problems were identified. WHAT IS KNOWN ALREADY: Many fundamental questions regarding the prevention, management, and consequences of infertility remain unanswered. This is a barrier to improving the care received by those people with fertility problems. STUDY DESIGN, SIZE, DURATION: Potential research questions were collated from an initial international survey, a systematic review of clinical practice guidelines, and Cochrane systematic reviews. A rationalized list of confirmed research uncertainties was prioritized in an interim international survey. Prioritized research uncertainties were discussed during a consensus development meeting. Using a formal consensus development method, the modified nominal group technique, diverse stakeholders identified the top 10 research priorities for each of the categories male infertility, female and unexplained infertility, medically assisted reproduction, and ethics, access, and organization of care. PARTICIPANTS/MATERIALS, SETTING, METHODS: Healthcare professionals, people with fertility problems, and others (healthcare funders, healthcare providers, healthcare regulators, research funding bodies and researchers) were brought together in an open and transparent process using formal consensus methods advocated by the James Lind Alliance. MAIN RESULTS AND THE ROLE OF CHANCE: The initial survey was completed by 388 participants from 40 countries, and 423 potential research questions were submitted. Fourteen clinical practice guidelines and 162 Cochrane systematic reviews identified a further 236 potential research questions. A rationalized list of 231 confirmed research uncertainties were entered into an interim prioritization survey completed by 317 respondents from 43 countries. The top 10 research priorities for each of the four categories male infertility, female and unexplained infertility (including age-related infertility, ovarian cysts, uterine cavity abnormalities, and tubal factor infertility), medically assisted reproduction (including ovarian stimulation, IUI, and IVF), and ethics, access, and organization of care, were identified during a consensus development meeting involving 41 participants from 11 countries. These research priorities were diverse and seek answers to questions regarding prevention, treatment, and the longer-term impact of infertility. They highlight the importance of pursuing research which has often been overlooked, including addressing the emotional and psychological impact of infertility, improving access to fertility treatment, particularly in lower resource settings, and securing appropriate regulation. Addressing these priorities will require diverse research methodologies, including laboratory-based science, qualitative and quantitative research, and population science. LIMITATIONS, REASONS FOR CAUTION: We used consensus development methods, which have inherent limitations, including the representativeness of the participant sample, methodological decisions informed by professional judgement, and arbitrary consensus definitions. WIDER IMPLICATIONS OF THE FINDINGS: We anticipate that identified research priorities, developed to specifically highlight the most pressing clinical needs as perceived by healthcare professionals, people with fertility problems, and others, will help research funding organizations and researchers to develop their future research agenda. STUDY FUNDING/ COMPETING INTEREST(S): The study was funded by the Auckland Medical Research Foundation, Catalyst Fund, Royal Society of New Zealand, and Maurice and Phyllis Paykel Trust. Geoffrey Adamson reports research sponsorship from Abbott, personal fees from Abbott and LabCorp, a financial interest in Advanced Reproductive Care, committee membership of the FIGO Committee on Reproductive Medicine, International Committee for Monitoring Assisted Reproductive Technologies, International Federation of Fertility Societies, and World Endometriosis Research Foundation, and research sponsorship of the International Committee for Monitoring Assisted Reproductive Technologies from Abbott and Ferring. Siladitya Bhattacharya reports being the Editor-in-Chief of Human Reproduction Open and editor for the Cochrane Gynaecology and Fertility Group. Hans Evers reports being the Editor Emeritus of Human Reproduction. Andrew Horne reports research sponsorship from the Chief Scientist's Office, Ferring, Medical Research Council, National Institute for Health Research, and Wellbeing of Women and consultancy fees from Abbvie, Ferring, Nordic Pharma, and Roche Diagnostics. M. Louise Hull reports grants from Merck, grants from Myovant, grants from Bayer, outside the submitted work and ownership in Embrace Fertility, a private fertility company. Neil Johnson reports research sponsorship from Abb-Vie and Myovant Sciences and consultancy fees from Guerbet, Myovant Sciences, Roche Diagnostics, and Vifor Pharma. José Knijnenburg reports research sponsorship from Ferring and Theramex. Richard Legro reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. Ben Mol reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. Ernest Ng reports research sponsorship from Merck. Craig Niederberger reports being the Co Editor-in-Chief of Fertility and Sterility and Section Editor of the Journal of Urology, research sponsorship from Ferring, and retains a financial interest in NexHand. Jane Stewart reports being employed by a National Health Service fertility clinic, consultancy fees from Merck for educational events, sponsorship to attend a fertility conference from Ferring, and being a clinical subeditor of Human Fertility. Annika Strandell reports consultancy fees from Guerbet. Jack Wilkinson reports being a statistical editor for the Cochrane Gynaecology and Fertility Group. Andy Vail reports that he is a Statistical Editor of the Cochrane Gynaecology & Fertility Review Group and of the journal Reproduction. His employing institution has received payment from HFEA for his advice on review of research evidence to inform their 'traffic light' system for infertility treatment 'add-ons'. Lan Vuong reports consultancy and conference fees from Ferring, Merck and Merck Sharp and Dohme. The remaining authors declare no competing interests in relation to the present work. All authors have completed the disclosure form. TRIAL REGISTRATION NUMBER: Not applicable.

Developing a core outcome set for future infertility research: an international consensus development study.

STUDY QUESTION: Can a core outcome set to standardize outcome selection, collection, and reporting across future infertility research be developed? SUMMARY ANSWER: A minimum data set, known as a core outcome set, has been developed for randomized controlled trials (RCT) and systematic reviews evaluating potential treatments for infertility. WHAT IS KNOWN ALREADY: Complex issues, including a failure to consider the perspectives of people with fertility problems when selecting outcomes, variations in outcome definitions, and the selective reporting of outcomes on the basis of statistical analysis, make the results of infertility research difficult to interpret. STUDY DESIGN, SIZE, DURATION: A three-round Delphi survey (372 participants from 41 countries) and consensus development workshop (30 participants from 27 countries). PARTICIPANTS/MATERIALS, SETTING, METHODS: Healthcare professionals, researchers, and people with fertility problems were brought together in an open and transparent process using formal consensus science methods. MAIN RESULTS AND THE ROLE OF CHANCE: The core outcome set consists of: viable intrauterine pregnancy confirmed by ultrasound (accounting for singleton, twin, and higher multiple pregnancy); pregnancy loss (accounting for ectopic pregnancy, miscarriage, stillbirth, and termination of pregnancy); live birth; gestational age at delivery; birthweight; neonatal mortality; and major congenital anomaly. Time to pregnancy leading to live birth should be reported when applicable. LIMITATIONS, REASONS FOR CAUTION: We used consensus development methods which have inherent limitations, including the representativeness of the participant sample, Delphi survey attrition, and an arbitrary consensus threshold. WIDER IMPLICATIONS OF THE FINDINGS: Embedding the core outcome set within RCTs and systematic reviews should ensure the comprehensive selection, collection, and reporting of core outcomes. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement, and over 80 specialty journals, including the Cochrane Gynaecology and Fertility Group, Ferility and Sterility, and Human Reproduction, have committed to implementing this core outcome set. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by the Catalyst Fund, Royal Society of New Zealand, Auckland Medical Research Fund, and Maurice and Phyllis Paykel Trust. Siladitya Bhattacharya reports being the Editor-in-Chief of Human Reproduction Open and an editor of the Cochrane Gynaecology and Fertility group. Hans Evers reports being the Editor Emeritus of Human Reproduction. José Knijnenburg reports research sponsorship from Ferring and Theramex. Richard Legro reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. Ben Mol reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. Craig Niederberger reports being the Co Editor-in-Chief of Fertility and Sterility and Section Editor of the Journal of Urology, research sponsorship from Ferring, and retains a financial interest in NexHand. Annika Strandell reports consultancy fees from Guerbet. Ernest Ng reports research sponsorship from Merck. Lan Vuong reports consultancy and conference fees from Ferring, Merck and Merck Sharp and Dohme. The remaining authors declare no competing interests in relation to the work presented. All authors have completed the disclosure form. TRIAL REGISTRATION NUMBER: Core Outcome Measures in Effectiveness Trials Initiative: 1023.

Standardizing definitions and reporting guidelines for the infertility core outcome set: an international consensus development study.

STUDY QUESTION: Can consensus definitions for the core outcome set for infertility be identified in order to recommend a standardized approach to reporting? SUMMARY ANSWER: Consensus definitions for individual core outcomes, contextual statements, and a standardized reporting table have been developed. WHAT IS KNOWN ALREADY: Different definitions exist for individual core outcomes for infertility. This variation increases the opportunities for researchers to engage with selective outcome reporting, which undermines secondary research and compromises clinical practice guideline development. STUDY DESIGN, SIZE, DURATION: Potential definitions were identified by a systematic review of definition development initiatives and clinical practice guidelines and by reviewing Cochrane Gynaecology and Fertility Group guidelines. These definitions were discussed in a face-to-face consensus development meeting, which agreed consensus definitions. A standardized approach to reporting was also developed as part of the process. PARTICIPANTS/MATERIALS, SETTING, METHODS: Healthcare professionals, researchers, and people with fertility problems were brought together in an open and transparent process using formal consensus development methods. MAIN RESULTS AND THE ROLE OF CHANCE: Forty-four potential definitions were inventoried across four definition development initiatives, including the Harbin Consensus Conference Workshop Group and International Committee for Monitoring Assisted Reproductive Technologies, 12 clinical practice guidelines, and Cochrane Gynaecology and Fertility Group guidelines. Twenty-seven participants, from 11 countries, contributed to the consensus development meeting. Consensus definitions were successfully developed for all core outcomes. Specific recommendations were made to improve reporting. LIMITATIONS, REASONS FOR CAUTION: We used consensus development methods, which have inherent limitations. There was limited representation from low- and middle-income countries. WIDER IMPLICATIONS OF THE FINDINGS: A minimum data set should assist researchers in populating protocols, case report forms, and other data collection tools. The generic reporting table should provide clear guidance to researchers and improve the reporting of their results within journal publications and conference presentations. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials statement, and over 80 specialty journals have committed to implementing this core outcome set. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by the Catalyst Fund, Royal Society of New Zealand, Auckland Medical Research Fund, and Maurice and Phyllis Paykel Trust. Siladitya Bhattacharya reports being the Editor-in-Chief of Human Reproduction Open and an editor of the Cochrane Gynaecology and Fertility group. Hans Evers reports being the Editor Emeritus of Human Reproduction. Richard Legro reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. Ben Mol reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. Craig Niederberger reports being the Editor-in-Chief of Fertility and Sterility and Section Editor of the Journal of Urology, research sponsorship from Ferring, and a financial interest in NexHand. Ernest Ng reports research sponsorship from Merck. Annika Strandell reports consultancy fees from Guerbet. Jack Wilkinson reports being a statistical editor for the Cochrane Gynaecology and Fertility group. Andy Vail reports that he is a Statistical Editor of the Cochrane Gynaecology & Fertility Review Group and of the journal Reproduction. His employing institution has received payment from HFEA for his advice on review of research evidence to inform their 'traffic light' system for infertility treatment 'add-ons'. Lan Vuong reports consultancy and conference fees from Ferring, Merck and Merck Sharp and Dohme. The remaining authors declare no competing interests in relation to the work presented. All authors have completed the disclosure form. TRIAL REGISTRATION NUMBER: Core Outcome Measures in Effectiveness Trials Initiative: 1023.