Obstetrics and Gynaecology - Research Publications

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    Adverse metabolic phenotype of adolescent girls with non-alcoholic fatty liver disease plus polycystic ovary syndrome compared with other girls and boys
    Ayonrinde, OT ; Adams, LA ; Doherty, DA ; Mori, TA ; Beilin, LJ ; Oddy, WH ; Hickey, M ; Sloboda, DM ; Olynyk, JK ; Hart, R (WILEY-BLACKWELL, 2016-05)
    BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) share risk associations of adiposity and insulin resistance. We examined the impact of a PCOS diagnosis on the metabolic phenotype of adolescent girls with NAFLD and compared this to girls without PCOS or NAFLD and to age-matched boys. METHODS: Community-based adolescents from the Raine Cohort participated in assessments for NAFLD (572 girls and 592 boys) and PCOS (244 girls). One hundred and ninety-nine girls attended both assessments. RESULTS: Amongst the 199 girls, PCOS was diagnosed in 16.1% and NAFLD in 18.6%. NAFLD was diagnosed in 10.1% of the boys. NAFLD was more prevalent in girls with PCOS than girls without PCOS (37.5% vs 15.1%, P = 0.003). Girls with NAFLD plus PCOS had greater adiposity (waist circumference, body mass index, suprailiac skinfold thickness [SST], serum androgens, high-sensitivity C-reactive protein, ferritin, homeostasis model assessment for insulin resistance (HOMA-IR), and lower serum sex hormone binding globulin levels than girls with NAFLD without a PCOS diagnosis (all P < 0.05). Girls with NAFLD plus PCOS had similar adiposity, HOMA-IR, and adiponectin levels to boys with NAFLD, but more adiposity, serum leptin and HOMA-IR than both girls and boys without NAFLD. PCOS (odds ratios 2.99, 95% confidence intervals 1.01-8.82, P = 0.048) and SST (odds ratios 1.14, 95% confidence intervals 1.08-1.20, P < 0.001) independently predicted NAFLD in adolescent girls, however, serum androgens and HOMA-IR levels did not. CONCLUSIONS: Adolescent girls with NAFLD plus PCOS have a similar metabolic phenotype to boys with NAFLD. Increasing SST and pre-existing PCOS independently predict NAFLD in adolescent girls.
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    Why should the obstetrics and gynaecology community care about sex and gender issues in health?
    Carcel, C ; Wainer, Z ; Henry, A ; Hickey, M (WILEY, 2019-04)
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    Exploring knowledge, attitudes and experience of genitourinary symptoms in women with early breast cancer on adjuvant endocrine therapy
    Sousa, M ; Peate, M ; Lewis, C ; Jarvis, S ; Willis, A ; Hickey, M ; Friedlander, M (WILEY, 2018-03)
    Clinical trials of adjuvant endocrine therapy in women with early breast cancer have consistently reported that genitourinary symptoms are common. However, little is known about women's experiences of genitourinary symptoms, their views about the symptoms and how they impact on their lives. The aim of this study was to explore knowledge, attitudes and experiences of genitourinary symptoms among women receiving adjuvant endocrine therapy for early breast cancer. Thirty-two semi-structured interviews were conducted and subjected to a rigorous qualitative analysis. Genitourinary symptoms were commonly reported to negatively impact on personal, social and physical activities, were often attributed to anxiety and stress and were a source of embarrassment. Women also commented on the limited information available or provided regarding the potential genitourinary adverse effects of adjuvant endocrine therapy. There was a general lack of awareness that their symptoms could be associated with or exacerbated by adjuvant endocrine therapy. Women indicated a preference to receive information and advice about potential management options from either their general practitioner or specialist. These findings underscore the importance of improving communication and increasing awareness among both clinicians and patients about the potential impact of adjuvant endocrine therapy on genitourinary symptoms.
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    Sex Differences in Infant Mortality: A Population Data Linkage Study of Brazilian Male-Female Twin Pairs
    Calais-Ferreira, L ; Mendonça, E ; Barreto, ME ; Dite, GM ; Hickey, M ; Ferreira, PH ; Scurrah, KJ ; Hopper, JL (Swansea University, 2020-12-07)
    IntroductionEpidemiological studies of twin pairs provide researchers with the opportunity to better understand the roles of genetics and the environment on human traits and health conditions. Twin births are also of interest for public health, given they are five times more likely to be of low birth weight and preterm compared to singletons. Male twin newborns are at high risk of mortality, although the causes of such disadvantage are still largely unknown. Objectives and ApproachWe deterministically linked population birth to death records of twins born in Brazil from 2012–2016, and probabilistically linked twins within pairs through a bespoke algorithm. We studied male-female twin pairs to investigate sex differences in infant mortality stratified by early neonatal (0–6 days), late neonatal (7–27 days) and late infant (28–365 days) deaths. We used conditional logistic regression to estimate odds ratios (OR) for male sex, adjusting for birth weight and matching for familial factors by design. ResultsOur algorithm successfully matched 101,382 twin pairs, 28,558 were male-female pairs included in the study. Average birthweight was 100g greater for males compared with females. We found that males were at higher risk of infant mortality than their female co-twins even after adjusting for birth weight and familial factors (aOR = 1.42, 95% CI: 1.22–1.66). The aORs for neonatal death increased from those born at less than 28 weeks to those born at 28–31, 32–26 and 37+ weeks: 1.47 (1.02–2.13), 1.73 (1.17–2.57), 1.99 (1.17–3.38), and 3.35 (1.29–8.73), respectively. Conclusion / ImplicationsMale twins have greater risk of infant and neonatal mortality compared with female co-twins, more so the higher the gestational age. Unmeasured familial and maternal factors may influence the role of birth weight in the association between sex and poor early life outcomes.
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    A core outcome set for future endometriosis research: an international consensus development study
    Duffy, JMN ; Hirsch, M ; Vercoe, M ; Abbott, J ; Barker, C ; Collura, B ; Drake, R ; Evers, JLH ; Hickey, M ; Horne, AW ; Hull, ML ; Kolekar, S ; Lensen, S ; Johnson, NP ; Mahajan, V ; Mol, BW ; Otter, A-S ; Puscasiu, L ; Rodriguez, MB ; Rombauts, L ; Vail, A ; Wang, R ; Farquhar, CM (WILEY, 2020-07)
    OBJECTIVE: To develop a core outcome set for endometriosis. DESIGN: Consensus development study. SETTING: International. POPULATION: One hundred and sixteen healthcare professionals, 31 researchers and 206 patient representatives. METHODS: Modified Delphi method and modified nominal group technique. RESULTS: The final core outcome set includes three core outcomes for trials evaluating potential treatments for pain and other symptoms associated with endometriosis: overall pain; improvement in the most troublesome symptom; and quality of life. In addition, eight core outcomes for trials evaluating potential treatments for infertility associated with endometriosis were identified: viable intrauterine pregnancy confirmed by ultrasound; pregnancy loss, including ectopic pregnancy, miscarriage, stillbirth and termination of pregnancy; live birth; time to pregnancy leading to live birth; gestational age at delivery; birthweight; neonatal mortality; and major congenital abnormalities. Two core outcomes applicable to all trials were also identified: adverse events and patient satisfaction with treatment. CONCLUSIONS: Using robust consensus science methods, healthcare professionals, researchers and women with endometriosis have developed a core outcome set to standardise outcome selection, collection and reporting across future randomised controlled trials and systematic reviews evaluating potential treatments for endometriosis. TWEETABLE ABSTRACT: @coreoutcomes for future #endometriosis research have been developed @jamesmnduffy.
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    Developing a core outcome set for future infertility research: an international consensus development study
    Duffy, JMN ; AlAhwany, H ; Bhattacharya, S ; Collura, B ; Curtis, C ; Evers, JLH ; Farquharson, RG ; Franik, S ; Giudice, LC ; Khalaf, Y ; Knijnenburg, JML ; Leeners, B ; Legro, RS ; Lensen, S ; Vazquez-Niebla, JC ; Mavrelos, D ; Mol, BWJ ; Niederberger, C ; Ng, EHY ; Otter, AS ; Puscasiu, L ; Rautakallio-Hokkanen, S ; Repping, S ; Sarris, I ; Simpson, JL ; Strandell, A ; Strawbridge, C ; Torrance, HL ; Vail, A ; van Wely, M ; Vercoe, MA ; Vuong, NL ; Wang, AY ; Wang, R ; Wilkinson, J ; Youssef, MA ; Farquhar, CM (OXFORD UNIV PRESS, 2020-12)
    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 (RCTs) 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, Fertility 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. The funder had no role in the design and conduct of the study, the collection, management, analysis or interpretation of data, or manuscript preparation. B.W.J.M. is supported by a National Health and Medical Research Council Practitioner Fellowship (GNT1082548). S.B. was supported by University of Auckland Foundation Seelye Travelling Fellowship. S.B. reports being the Editor-in-Chief of Human Reproduction Open and an editor of the Cochrane Gynaecology and Fertility group. J.L.H.E. reports being the Editor Emeritus of Human Reproduction. J.M.L.K. reports research sponsorship from Ferring and Theramex. R.S.L. reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. B.W.J.M. reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. C.N. 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. A.S. reports consultancy fees from Guerbet. E.H.Y.N. reports research sponsorship from Merck. N.L.V. 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.
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    Updated adolescent diagnostic criteria for polycystic ovary syndrome: impact on prevalence and longitudinal body mass index trajectories from birth to adulthood
    Tay, CT ; Hart, RJ ; Hickey, M ; Moran, LJ ; Earnest, A ; Doherty, DA ; Teede, HJ ; Joham, AE (BMC, 2020-12-11)
    BACKGROUND: Polycystic ovary syndrome (PCOS) is challenging to diagnose. While the 2003 Rotterdam criteria are widely used for adults, the 2018 international PCOS guideline recommended updated Rotterdam criteria with both hyperandrogenism and oligo-anovulation for adolescents based on evidence-informed expert consensus. This study compared the prevalence of PCOS using updated and original Rotterdam criteria in community-based adolescents and explored long-term body mass index (BMI) trajectories across different diagnostic phenotypes. METHODS: Overall, 227 postmenarchal adolescent females from the prospective cohort Raine Study undertook comprehensive PCOS assessment at age 14-16 years. Detailed anthropometric measurements were collected from birth until age 22 years. Cross-sectional and longitudinal BMI were analyzed using t tests and generalized estimating equations. RESULTS: PCOS was diagnosed in 66 (29.1%) participants using original criteria versus 37 (16.3%) participants using updated Rotterdam criteria. Using updated criteria, participants with PCOS had higher BMI than participants without PCOS from prepubertal. Only the phenotype meeting the updated criteria was significantly associated with higher long-term BMI gain whereas other PCOS phenotypes had similar BMI trajectories to participants without PCOS (p < 0.001). CONCLUSIONS: The use of the 2018 updated Rotterdam criteria reduces over-diagnosis of PCOS in adolescents and identifies those at the greatest risk of long-term weight gain, a key contributor to disease severity and long-term health implications. The BMI trajectories of females with PCOS on updated criteria diverge prepubertally compared to those without PCOS. This work supports targeting adolescents diagnosed with PCOS on the 2018 updated criteria for early lifestyle interventions to prevent long-term health complications.
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    Standardizing definitions and reporting guidelines for the infertility core outcome set: an international consensus development study
    Duffy, JMN ; Bhattacharya, S ; Bofill, M ; Collura, B ; Curtis, C ; Evers, JLH ; Giudice, LC ; Farquharson, RG ; Franik, S ; Hickey, M ; Hull, ML ; Jordan, V ; Khalaf, Y ; Legro, RS ; Lensen, S ; Mavrelos, D ; Mol, BW ; Niederberger, C ; Ng, EHY ; Puscasiu, L ; Repping, S ; Sarris, I ; Showell, M ; Strandell, A ; Vail, A ; van Wely, M ; Vercoe, M ; Vuong, NL ; Wang, AY ; Wang, R ; Wilkinson, J ; Youssef, MA ; Farquhar, CM (OXFORD UNIV PRESS, 2020-12)
    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. J.L.H.E. reports being the Editor Emeritus of Human Reproduction. R.S.L. reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. B.W.M. reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. C.N. 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. E.H.Y.N. reports research sponsorship from Merck. A.S. reports consultancy fees from Guerbet. J.W. reports being a statistical editor for the Cochrane Gynaecology and Fertility Group. A.V. 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 Human Fertilisation and Embryology Authority for his advice on review of research evidence to inform their 'traffic light' system for infertility treatment 'add-ons'. N.L.V. 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.
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    Top 10 priorities for future infertility research: an international consensus development study
    Duffy, JMN ; Adamson, GD ; Benson, E ; Bhattacharya, S ; Bofill, M ; Brian, K ; Collura, B ; Curtis, C ; Evers, JLH ; Farquharson, RG ; Fincham, A ; Franik, S ; Giudice, LC ; Glanville, E ; Hickey, M ; Horne, AW ; Hull, ML ; Johnson, NP ; Jordan, V ; Khalaf, Y ; Knijnenburg, JML ; Legro, RS ; Lensen, S ; MacKenzie, J ; Mavrelos, D ; Mol, BW ; Morbeck, DE ; Nagels, H ; Ng, EHY ; Niederberger, C ; Otter, AS ; Puscasiu, L ; Rautakallio-Hokkanen, S ; Sadler, L ; Sarris, I ; Showell, M ; Stewart, J ; Strandell, A ; Strawbridge, C ; Vail, A ; van Wely, M ; Vercoe, M ; Vuong, NL ; Wang, AY ; Wang, R ; Wilkinson, J ; Wong, K ; Wong, TY ; Farquhar, CM (OXFORD UNIV PRESS, 2020-12)
    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 was 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 judgment 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. G.D.A. 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. J.L.H.E. reports being the Editor Emeritus of Human Reproduction. A.W.H. 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.L.H. reports grants from Merck, grants from Myovant, grants from Bayer, outside the submitted work and ownership in Embrace Fertility, a private fertility company. N.P.J. reports research sponsorship from AbbVie and Myovant Sciences and consultancy fees from Guerbet, Myovant Sciences, Roche Diagnostics and Vifor Pharma. J.M.L.K. reports research sponsorship from Ferring and Theramex. R.S.L. reports consultancy fees from AbbVie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. B.W.M. reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. E.H.Y.N. reports research sponsorship from Merck. C.N. 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. J.S. 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. A.S. reports consultancy fees from Guerbet. J.W. reports being a statistical editor for the Cochrane Gynaecology and Fertility Group. A.V. reports that he is a Statistical Editor of the Cochrane Gynaecology & Fertility Review Group and the journal Reproduction. His employing institution has received payment from Human Fertilisation and Embryology Authority for his advice on review of research evidence to inform their 'traffic light' system for infertility treatment 'add-ons'. N.L.V. 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: N/A.