Intravenous iron versus blood transfusion for postpartum anemia: a systematic review and meta-analysis

BACKGROUND

Intravenous iron (IV-iron) is used as an alternative to, or alongside, red blood cell transfusion (RBC-T) to treat more severe postpartum anemia (PPA), although optimal treatment options remain unclear. No previous systematic reviews have examined IV-iron and RBC-T, including patient-reported outcomes and hematological responses.

METHODS

A systematic review and meta-analysis of randomized trials comparing IV-iron and RBC-T with each other, oral iron, no treatment, and placebo for the treatment of PPA. Key inclusion criteria were PPA (hemoglobin < 12 g/dL) and IV-iron or RBC-T as interventions. Key exclusion criteria were antenatal IV-iron or RBC-T. Fatigue was the primary outcome. Secondary outcomes included hemoglobin and ferritin concentrations, and adverse events. From 27th August 2020 to 26th September 2022, databases, registries, and hand searches identified studies. A fixed-effect meta-analysis was undertaken using RevMan (5.4) software. The quality of the studies and the evidence was assessed using the Cochrane Risk of Bias table, and Grading of Recommendations, Assessment, Development, and Evaluation. This review is registered with the Prospective Register of Systematic Reviews (CRD42020201115).

RESULTS

Twenty studies and 4196 participants were included: 1834 assigned IV-iron, 1771 assigned oral iron, 330 assigned RBC-T, and 261 assigned non-intervention. Six studies reported the primary outcome of fatigue (1251 participants). Only studies of IV-iron vs. oral iron (15 studies) were available for meta-analysis. Of these, three reported on fatigue using different scales; two were available for meta-analysis. There was a significant reduction in fatigue with IV-iron compared to oral iron (standardized mean difference - 0.40, 95% confidence interval (CI) - 0.62, - 0.18, I2 = 0%). The direction of effect also favored IV-iron for hemoglobin (mean difference (MD) 0.54 g/dL, 95% confidence interval (CI) 0.47, 0.61, I2 = 91%), ferritin, (MD 58.07 mcg/L, 95% CI 55.74, 60.41, I2 = 99%), and total adverse events (risk-ratio 0.63, 95% CI 0.52, 0.77, I2 = 84%). The overall quality of the evidence was low-moderate.

DISCUSSION

For all outcomes, the evidence for RBC-T, compared to IV-iron, non-intervention, or dose effects of RBC-T is very limited. Further research is needed to determine whether RBC-T or IV-iron for the treatment of PPA is superior for fatigue and hematological outcomes.

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. 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.

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.

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 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.

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.

Non-publication and publication bias in reproductive medicine: a cohort analysis

STUDY QUESTION

Does publication bias or non-publication exist in fertility trials presented as conference abstracts?

SUMMARY ANSWER

This study did not detect any publication bias; however, it did identify a high level of non-publication, with only 49% of abstracts reaching full-text publication four or more years after abstract presentation.

WHAT IS KNOWN ALREADY

Systematic reviews of randomized controlled trials (RCTs) are the foundation of evidence based medicine. Non-publication or publication deficit refer to the failure to publish trial results. A publication bias exists when there is any tendency on the parts of the investigators or editors to fail to publish study results on the basis or strength of the study findings. Both present a serious problem for researchers, clinicians and policymakers alike, and ultimately impact on patient care.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study identified 337 fertility RCTs presented as conference abstracts between 2007 and 2010, as captured by an electronic search of the Cochrane Gynaecology and Fertility Database. After excluding ineligible trials and duplicates, 224 abstracts remained.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A search for the full-text papers of each abstract was undertaken in Pubmed, MEDLINE, Embase, CINAHL and Google in May 2015 using a probabilistic approach. Trial authors were contacted to query the publication status of abstracts when no full-text was identified. The association between individual variables and the probability of publication, and time to publication, was assessed using logistic regression and Cox regression, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 224 included abstracts, only 110 (49%; 95% CI: 42.6, 55.6) were found to be published as full-text articles. Publication bias was not identified in this cohort; studies with positive results had a similar probability of reaching full-text publication 52/113 (46%; 95% CI: 37.0, 55.3) as studies with non-positive (negative or null) results 58/111 (52%; 95% CI: 17.8, 33.9) (adjusted odds ratio (AOR): 1.02; 95% CI: 0.53, 1.97). Similarly, the time from abstract presentation to full-text publication was similar in studies with positive and non-positive results. Oral presentations were more likely to be published, and to be published sooner, than poster presentations (poster presentation AOR: 0.31; 95% CI: 0.15, 0.61 and adjusted hazard ratio (AHR): 0.57; 95% CI: 0.38, 0.86). Studies that were not registered were less likely to be published and to have delayed publication, than studies which were registered either prospectively or retrospectively (AOR: 0.14; 95% CI: 0.04, 0.44 and AHR: 0.43; 95% CI: 0.25, 0.72). Abstracts which were presented a longer time ago also had a higher probability of reaching full-text publication (P  = 0.01).

LIMITATIONS, REASONS FOR CAUTION

Commencing with a cohort of RCTs from ethics committee registers may provide a better picture of the extent of non-publication and publication bias, as not all trials reach the stage of abstract presentation. It is also possible that the search did not identify all published trials, as some may have been published after the follow-up period.

WIDER IMPLICATIONS OF THE FINDINGS

This study did not identify any publication bias. However, only half of the abstracts in this cohort have been published as full-text articles, four or more years after their presentation at a conference. This is similar to publication rates reported previously for fertility trials, and is despite increasing awareness of the importance of publishing trial results, and subsequent requirements for all RCTs to be registered prior to trial initiation. A better understanding of the reasons for non-publication should assist in facilitating the prompt full-text publication of RCTs in the future.

STUDY FUNDING/COMPETING INTEREST(S)

Funding provided from the University of Auckland. All authors declare they have no conflicts of interest in relation to this article.

TRIAL REGISTRATION NUMBER

Not applicable.

Time-lapse in the IVF-lab: how should we assess potential benefit?

Time-lapse imaging of embryos has been widely introduced to fertility laboratories worldwide with the aim of identifying the best quality embryos to transfer that will ultimately improve IVF success rates. In this opinion paper, we explore the lack of evidence of benefit of this novel intervention, analyse the methodological flaws of current studies, offer ideal study designs that assess the various features of time-lapse imaging, and discuss forthcoming studies. In particular, we emphasize the ethical aspects of hastily adopting a costly technology without current high level evidence of improved live birth rates, safety and cost effectiveness.

Distance as a risk factor for amputation in patients with diabetes: a case-control study

We studied the association between amputation and distance of patients' residences to a diabetes care centre. We performed a case-control study matching each case (amputation) with 5 controls (no amputation) by age and sex. We compared the distance of residence to the diabetes centre, duration and type of diabetes, haemoglobin-A1c levels and foot examination findings for cases and controls. We analysed the association between distance and the strongest predictors of amputation. Sixty-six cases of amputation and 313 controls were identified. Distance of residence was 12.1km greater for cases (p = 0.028). In multivariate analysis, only diabetes duration (OR/year 1.07, 1.03 to 1.11) and neuropathy (OR 10.73, 4.55 to 25.74) were significantly associated with amputation. Patients with neuropathy resided 97 km further than those without neuropathy (p = 0.01). Patients requiring amputation reside at greater distances from the diabetes centre, possibly due to higher rates of neuropathy.

Methodological quality of systematic reviews in subfertility: a comparison of Cochrane and non-Cochrane systematic reviews in assisted reproductive technologies

STUDY QUESTION

Are there differences in the methodological quality of Cochrane systematic reviews (CRs) and non-Cochrane systematic reviews (NCRs) of assisted reproductive technologies?

SUMMARY ANSWER

CRs on assisted reproduction are of higher methodological quality than similar reviews published in other journals.

WHAT IS KNOWN ALREADY

The quality of systematic reviews varies.

STUDY DESIGN, SIZE AND DURATION

This was a cross-sectional study of 30 CR and 30 NCR systematic reviews that were randomly selected from the eligible reviews identified from a literature search for the years 2007-2011.

MATERIALS, SETTING AND METHODS

We extracted data on the reporting and methodological characteristics of the included systematic reviews. We assessed the methodological quality of the reviews using the 11-domain Measurement Tool to Assess the Methodological Quality of Systematic Reviews (AMSTAR) tool and subsequently compared CR and NCR systematic reviews.

MAIN RESULTS AND THE ROLE OF CHANCE

The AMSTAR quality assessment found that CRs were superior to NCRs. For 10 of 11 AMSTAR domains, the requirements were met in >50% of CRs, but only 4 of 11 domains showed requirements being met in >50% of NCRs. The strengths of CRs are the a priori study design, comprehensive literature search, explicit lists of included and excluded studies and assessments of internal validity. Significant failings in the CRs were found in duplicate study selection and data extraction (67% meeting requirements), assessment for publication bias (53% meeting requirements) and reporting of conflicts of interest (47% meeting requirements). NCRs were more likely to contain methodological weaknesses as the majority of the domains showed <40% of reviews meeting requirements, e.g. a priori study design (17%), duplicate study selection and data extraction (17%), assessment of study quality (27%), study quality in the formulation of conclusions (23%) and reporting of conflict of interests (10%).

LIMITATIONS, REASONS FOR CAUTION

The AMSTAR assessment can only judge what is reported by authors. Although two of the five authors are involved in the production of CRs, the risk of bias was reduced by not involving these authors in the assessment of the systematic review quality.

WIDER IMPLICATIONS OF THE FINDINGS

Not all systematic reviews are equal. The reader needs to consider the quality of the systematic review when they consider the results and the conclusions of a systematic review.

STUDY FUNDING/COMPETING INTEREST(S)

There are no conflicts with any commercial organization. Funding was provided for the students by the summer studentship programme of the Faculty of Medical and Health Sciences of the University of Auckland.

Morphology and Microtopology of Cation-Exchange Polymers and the Origin of the Overlimiting Current

In electrodialysis desalination processes, the operating current density is limited by concentration polarization. In contrast to other membrane processes such as ultrafiltration, in electrodialysis, current transport above the limiting current is possible. In this work, the origin of the overlimiting current at cation-exchange polymers is investigated. We show that, under certain experimental conditions, electroconvection is the origin of the overlimiting conductance. The theory concerning electroconvection predicts a shortening of the plateau length of membranes with increased conductive or geometrical heterogeneity. We investigate the influence of these two parameters and show that the creation of line undulations on the membrane surface normal to the flow direction, having distances in the range of approximately 50-200% of the boundary-layer thickness, lead to an earlier onset of the overlimiting current. The plateau length of the undulated membranes is reduced by up to 60% compared to that of a flat membrane. These results verify the existence of electroconvection as a mechanism destabilizing the laminar boundary layer at the liquid-membrane interface and causing ionic transport above the limiting current density.

The C-terminal C1 cassette of the N -methyl-D-aspartate receptor 1 subunit contains a bi-partite nuclear localization sequence

The N -methyl-D-aspartate receptor (NMDAR) is a multimeric transmembrane protein composed of at least two subunits. One subunit, NR1, is derived from a single gene and can be subdivided into three regions: the N-terminal extracellular domain, the transmembrane regions, and the C-terminal intracellular domain. The N-terminal domain is responsible for Mg2+ metal ion binding and channel activity, while the transmembrane domains are important for ion channel formation. The intracellular C-terminal domain is involved in regulating receptor activity and subcellular localization. Our recent experiments indicated that the intracellular C-terminal domain, when expressed independently, localizes almost exclusively in the nucleus. An examination of the amino acid sequence reveals the presence of a putative nuclear localization sequence (NLS) in the C1 cassette of the NR1 intracellular C-terminus. Using an expression vector designed to test whether a putative NLS sequence is a valid, functional NLS, we have demonstrated that a bi-partite NLS does in fact exist within the NR1-1 C-terminus. Computer algorithms identified a putative helix-loop-helix motif that spanned the C0C1 cassettes of the C-terminus. These data suggest that the NR1 subunit may represent another member of a family of transmembrane proteins that undergo intramembrane proteolysis, releasing a cytosolic peptide that is actively translocated to the nucleus leading to alterations in gene regulation.

Development of an environmentally benign process for the production of fatty acid methyl esters

The production of fatty acid methyl esters (FAME) is an important intermediate step in oleochemistry. The oleochemical production route starts with the renewable raw materials fat and oil and ends at fatty alcohols and different special products. Fatty acid methyl esters can be formed at mild reaction temperatures by transesterification of natural triglycerides (fats and oils). This contribution will show the development of a continuous process which is considering the main principles of production integrated environmental protection. The main advantages of this process are low energy consumption and minimal waste production. The process alternatives are shown and a scope on future problems which have to be solved to reach a real additional improvement of the fatty acid methyl esters production is given.

Molecular mechanism of action at estrogen receptor alpha of a new clinically relevant antiestrogen (GW7604) related to tamoxifen

Tamoxifen is the endocrine treatment of choice for all stages of estrogen receptor (ER)-positive breast cancer, and it is the first drug approved to reduce the incidence of breast cancer in high-risk women. Unfortunately, tamoxifen also possesses some estrogen-like effects in the uterus that cause a modest increase in the risk of endometrial cancer. GW5638 is a tamoxifen derivative with a novel carboxylic acid side chain with no uterotropic activity in the rat (Willson et al., J Med Chem, 1994, 37:1550-1552). We have compared and contrasted the actions of 4-hydroxytamoxifen (4-OHT, the active metabolite of tamoxifen) with GW7604 [the presumed metabolite of GW5638 in breast (MCF-7) and endometrial (ECC-1) cell lines in vitro]. GW7604 did not cause the growth of ECC-1 cells at any concentration (10(-11)-10(-6) M), but 4-OHT was weakly estrogen-like at low concentrations (10(-11)-10(-10) M). Compounds (10(-7) M) blocked the growth promoting action of estradiol (10(-10) M) in both ECC-1 and MCF-7 cells. Western blotting was used to show that GW7604 and raloxifene did not affect ER levels significantly, compared with controls, in MCF-7 cells; whereas the pure antiestrogen ICI182,780 decreased ER levels (P < 0.05). An assay system was used that can classify compounds into tamoxifen-like, raloxifene-like, or pure antiestrogens. The assay depends on the activation of the transforming growth factor alpha (TGFalpha) gene in situ by wild-type or D351Y mutant ER stably transfected into MDA-MB-231 cells (MacGregor-Schafer et al., Cancer Res, 1999, 59:4308-4313). GW7604 inhibited both estradiol (10(-9) M) and 4-OHT (10(-8), 10(-7) M) induction of TGFalpha in a concentration related manner (10(-9)-10(-6) M). GW7604 and raloxifene stimulated TGFalpha with the D351Y ER. In contrast, ICI 182,780 (10(-6) M) did not initiate TGFalpha and blocked the induction of TGFalpha with GW7604, raloxifene, and 4-OHT in D351Y-transfected cells. Using computer-assisted molecular models of ER complexes, we found that the antiestrogenic side chain of 4-OHT weakly interacted with the surface amino acid 351 (aspartate), but the carboxylic acid of GW7604 caused a strong repulsion of aspartate 351. We propose that GW7604 is less estrogen-like than 4-OHT, because it disrupts the surface charge around aa351 required for coactivator docking in the 4-OHT:ER complex. This charge is restored in the D351Y ER, thus converting GW7604 from an antiestrogen to an estrogen-like molecule.

Renal dysfunction associated with the perioperative use of diclofenac

Postoperative renal dysfunction in rats is induced by ketorolac dosed concurrently with gentamicin. Herein, we report the renal effects of diclofenac in four groups of rats: control (C = anesthesia, surgery); diclofenac (D = anesthesia, surgery, diclofenac 18 mg x kg(-1) x d(-1)); gentamicin (G = anesthesia, surgery, gentamicin 20 mg x kg(-1) x d(-1)); and diclofenac and gentamicin (DG = anesthesia, surgery, diclofenac, gentamicin). Renal function, after three treatment days, was assessed using histology, p-aminohippurate (PAH), and iothalamate (IOT) clearances, serum and urine electrolytes, osmolality, urea, and creatinine. Urine output was increased (from 5.2 to 12.5 mL/24 h), and urine osmolality was decreased (from 2121 to 883 mOsm/kg) in the DG group. PAH and IOT clearances were decreased in the G and DG groups (PAH by 18%, IOT by 22%; PAH by 38%, IOT by 43%, respectively); there were no changes in the C and D groups. Urea and creatinine clearances were decreased by 61% and 43%, respectively, in the DG group. Kidney sections showed the most severe pathologic changes in the DG group. Our data indicate that the perioperative combination of diclofenac and gentamicin was deleterious to renal function.

IMPLICATIONS

Diclofenac alone does not result in significant perioperative renal dysfunction, but the combination of gentamicin and diclofenac is deleterious to renal function. Considering this and previous findings, the evidence suggests that treatment with aminoglycosides may be a significant risk factor for inducing perioperative renal failure during treatment with nonsteroidal antiinflammatory drugs.

Acidic isoforms of chorionic gonadotrophin in European and Samoan women are associated with hyperemesis gravidarum and may be thyrotrophic

OBJECTIVE

There is conflicting evidence concerning the role of human chorionic gonadotrophin (hCG) in the aetiology of hyperemesis gravidarum (HG); particular isoforms of hCG may be the critical factor. Ethnic differences in HG prevalence and putative thyrotrophic effects of hCG may also relate to differences in hCG isoform profiles. To address these issues we examined the relationship of hCG isoforms to HG and thyroid function tests in two groups of women from ethnic backgrounds with significantly different HG prevalence rates.

PATIENTS AND DESIGN

We enrolled 10 European and 10 Samoan women with HG and an equally sized non-hyperemetic, gestational stage matched control group.

MEASUREMENTS

We administered a questionnaire, generated serum hCG charge-isoform profiles by chromatofocusing and measured the serum concentrations of total hCG, oestradiol (E2), thyrotrophin (TSH) and free thyroxine (FT4).

RESULTS

The mean serum total hCG levels were highest in the Samoan hyperemetics (176,268 IU/l), and overall higher in hyperemetics compared with controls (159,770 IU/l vs. 86,420 IU/l, P < 0.001). When compared with controls, hyperemetics displayed increased hCG concentrations in the more acidic half (pH < 4) of the chromatofocusing pH range (89,843 IU/l vs. 41,146 IU/l, P < 0.003). Serum E2 levels did not differ between the four groups, but correlated with the hCG concentration between pH 5.2 and 4.01. Mean serum TSH levels were significantly lower in hyperemetics than in controls (0.33 mIU/l vs. 1.19 mIU/l, P < 0.001) and correlated with the hCG concentration between pH 4.6 and 2.8, while serum FT4 correlated with the hCG concentration below pH 4.0.

CONCLUSIONS

Acidic isoforms of hCG may play a role in the aetiology of HG and gestational thyrotoxicosis. Minor ethnic differences in hCG isoform profiles were observed, but the relationship of acidic hCG isoforms to HG and serum thyroid hormone levels was largely independent of the patients' ethnicity. The mechanisms by which acidic isoforms might provoke nausea remain uncertain, but do not seem to involve E2, while the longer half-life of acidic hCG isoforms may result in increased in vivo TSH receptor cross-talk with resultant thyrotrophic effects.

Factors influencing ketorolac-associated perioperative renal dysfunction

Nonsteroidal antiinflammatory drugs (NSAIDs) are useful for the treatment of postoperative pain, but there is continuing concern about adverse effects on renal function. We studied the renal effects of ketorolac in an animal model using Fischer 344 rats undergoing isoflurane anesthesia and laparotomy. Treatment groups--control (C), ketorolac (5 mg x kg(-1) x d(-1)) (K), large-dose ketorolac (15 mg x kg(-1) x d(-1)) (KH), dehydration-ketorolac (5 mg x kg(-1) x d(-1)) (DK), gentamicin (20 mg x kg(-1) x d(-1)) (G), and gentamicin (20 mg x kg(-1) x d(-1)) with ketorolac (5 mg x kg(-1) x d(-1)) (GK)--each comprised 10 animals. Renal function was assessed before laparotomy and after 3 treatment days using concurrent paraaminohippurate and iothalamate clearances, respectively, to estimate renal plasma flow and glomerular filtration rate, and by measuring serum and urine electrolytes, osmolality, urea, and creatinine. A significant increase in serum potassium was found in the GK and DK groups. There were no major changes in renal function in the C, K, KH, and DK groups. Mild renal dysfunction was found in the G group. We found severe and consistent changes in renal function, accompanied by severe, widespread histological changes of acute tubular necrosis, in the GK group. In this postoperative rat model, the combination of ketorolac and gentamicin was deleterious to renal function.

IMPLICATIONS

We examined the renal effects of the nonsteroidal antiinflammatory drug ketorolac. Renal function was measured in rats before and after surgery and 3 days' drug administration; the kidneys studied by using microscopy. Only ketorolac plus the antibiotic gentamicin produced marked changes in kidney function and structure.

The incidence of hyperemesis gravidarum is increased among Pacific Islanders living in Wellington

AIMS

To compare the incidence of hyperemesis gravidarum among Pacific Islanders living in Wellington with nonPacific Islanders and to investigate some properties of the disorder.

METHODS

Data were collected on all first time admissions to Wellington Women's Hospital for hyperemesis gravidarum over a 5-year period. Women were classified as having severe hyperemesis gravidarum if abnormalities of serum electrolytes and liver function tests results were present and as less severe if these abnormalities were absent. Almost all women had ketonuria. Mantel-Haenszel odds ratios, chi 2 analysis and Fisher's 2-tailed exact test were used for statistical analysis.

RESULTS

The proportion of hyperemesis gravidarum patients who were Pacific Islanders was significantly increased when compared to their proportion in a control group (p < 0.01). The difference remained significant when the hyperemesis patients were divided into less and more severe. Abnormal thyroid function test results were more common among Pacific Island patients than among nonPacific Island patients. This difference was significant (p < 0.01) only in the less severe group.

CONCLUSION

The incidence of hyperemesis gravidarum is significantly increased among Pacific Island women (especially Samoans) living in Wellington and is often associated with abnormalities of thyroid function test results.

Growth hormone responses to GRF 1-29 in patients with primary hypothyroidism before and during replacement therapy with thyroxine

It is well known that hypothyroidism is frequently associated with impaired GH responses to different stimuli. In the present study we have evaluated GH responses to GH-releasing factor (GRF) in patients with primary hypothyroidism before and during T4 replacement therapy. Fourteen patients (age range 26-60 years) underwent two GRF tests (1 microgram/kg) before and during replacement therapy (150 micrograms/d). Administration of T4 increased peak GH responses to GRF in 9 patients and in the group as a whole (mean +/- SEM, 17.0 +/- 2.8 vs 32.6 +/- 5.7 mU/l, P less than 0.02). When the data are analysed by means of area under the curve (AUC), the GH response to GRF was increased by T4 in 10 patients and in the group as a whole (mean +/- SEM, 51.7 +/- 14.3 vs 101.5 +/- 28.1, P less than 0.02). These data indicate that thyroid hormone replacement therapy enhances the responsiveness of the somatotroph to GRF 1-29 in patients with primary hypothyroidism.

Lack of effect of muscarinic cholinergic blockade on the GH responses to GRF 1-29 and TRH in acromegalic subjects

It is well known that muscarinic cholinergic blockade either reduces or abolishes stimulated GH release in normal subjects. In this study we have investigated whether cholinergic muscarinic blockade could reduce the GH responses to GRF 1-29 and TRH in acromegalic subjects. Eight acromegalic subjects underwent two GRF tests (GRF 1-29, 1 microgram/kg i.v.) with and without pirenzepine (0.6 mg/kg, i.v.). A further four of these patients received TRH (200 micrograms/kg, i.v.) on separate occasions with and without pirenzepine (0.6 mg/kg, i.v.). Cholinergic muscarinic blockade did not alter the GH responses to GRF and TRH in patients with acromegaly. These findings are in contrast with previous data reported on the effects of cholinergic blockade on stimulated GH levels in normal subjects and in patients with type I diabetes mellitus and are compatible with the view that somatotroph adenomas are functionally disconnected from hypothalamic control mechanisms.

Growth hormone responses to growth hormone-releasing factor (1-29) in euthyroid, hypothyroid and hyperthyroid rats

In order to investigate whether the impaired GH secretion associated with hypothyroidism and hyperthyroidism is due to a hypothalamic or a pituitary disorder, we have studied plasma GH responses to GH-releasing factor (1-29) (GRF) in euthyroid, hypothyroid and hyperthyroid rats. Hypothyroid rats showed a significant (P less than 0.001) reduction in GH responses to GRF (5 micrograms/kg) at 5 min (350 +/- 35 vs 1950 +/- 260 micrograms/l), 10 min (366 +/- 66 vs 2320 +/- 270 micrograms/l) and 15 min after GRF injection (395 +/- 72 vs 1420 +/- 183 micrograms/l; mean +/- S.E.M.) compared with euthyroid rats. Hyperthyroid rats showed a significant (P less than 0.05) decrease in GH responses to 5 micrograms GRF/kg after 30 min (200 +/- 14 vs 325 +/- 35 micrograms/l) but not at other time-points, or after the administration of 1 microgram GRF/kg. These data indicate that in hypothyroidism and perhaps hyperthyroidism there is an alteration in the responsiveness of the somatotroph to GRF administration.

Influence of dopaminergic, adrenergic and cholinergic blockade and TRH administration on GH responses to GRF 1-29

In order to establish the influence of dopaminergic, alpha-adrenergic and cholinergic pathways on GRF-mediated GH release we have studied the GH responses to GRF 1-29 (100 or 50 micrograms as i.v. bolus) alone and in combination with metoclopramide (MCP, 10 mg, i.v.), thymoxamine (THYM, 210 micrograms/min, 150 min infusion), and atropine (1.2 mg, i.v.). We have also investigated any possible interaction between TRH and GRF in view of the reported inhibitory effects of TRH infusion on stimulated GH release. Dopaminergic and alpha-adrenergic blockade with MCP and THYM respectively, did not have any effect on the GH responses to GRF. This lack of effect strongly suggests that any action which these neurotransmitters may exert on GH secretion is not at a pituitary level. TRH did not modify the GH response to GRF suggesting that the inhibitory effect on stimulated GH secretion is exerted at a hypothalamic level. In contrast, GH responses to GRF were significantly reduced by prior administration of atropine. These data support the view that cholinergic pathways play an important role in the regulation of GH secretion and such control may be exerted at both hypothalamic and pituitary levels.