Siladitya Bhattacharya

University of Aberdeen, Aberdeen, Scotland, United Kingdom

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Publications (133)789.68 Total impact

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    ABSTRACT: BACKGROUND A substantial minority of women undergoing IVF will under-respond to controlled ovarian hyperstimulation. These women—so-called ‘poor responders’—suffer persistently reduced success rates after IVF. Currently, no single intervention is unanimously accepted as beneficial in overcoming poor ovarian response (POR). This has been supported by the available research on POR, which consists mainly of randomized controlled trials (RCTs ) with an inherent high-risk of bias. The aim of this review was to critically appraise the available experimental trials on POR and provide guidance towards more useful—less wasteful—future research. METHODS A comprehensive review was undertaken of RCTs on ‘poor responders’ published in the last 15 years. Data on various methodological traits as well as important clinical characteristics were extracted from the included studies and summarized, with a view to identifying deficiencies from which lessons can be learned. Based on this analysis, recommendations were provided for further research in this field of assisted conception. RESULTS We selected and analysed 75 RCTs. A valid, ‘low-risk’ randomization method was reported in three out of four RCTs. An improving trend in reporting concealment of patient allocation was also evident over the 15-year period. In contrast
    No preview · Article · Feb 2016 · Human Reproduction Update
  • Sohinee Bhattacharya · Siladitya Bhattacharya

    No preview · Article · Jan 2016 · Nature Reviews Endocrinology
  • David J. McLernon · Abha Maheshwari · Amanda J. Lee · Siladitya Bhattacharya
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    ABSTRACT: Study question: What is the chance of a live birth following one or more linked complete cycles of IVF (including ICSI)? Summary answer: The chance of a live birth after three complete cycles of IVF was 42.3% for treatment commencing from 1999 to 2007. What is known already: IVF success has generally been reported on the basis of live birth rates after a single episode of treatment resulting in the transfer of a fresh embryo. This fails to capture the real chance of having a baby after a number of complete cycles-each involving the replacement of fresh as well as frozen-thawed embryos. Study design, size and duration: Population-based observational cohort study of 178 898 women between 1992 and 2007. Participants/materials, setting, methods: Participants included all women who commenced IVF treatment at a licenced clinic in the UK as recorded in the Human Fertilisation and Embryology Authority (HFEA) national database. Exclusion criteria included women whose treatment involved donor insemination, egg donation, surrogacy and the transfer of more than three embryos. Cumulative rates of live birth, term (>37 weeks) singleton live birth, and multiple pregnancy were estimated for two time-periods, 1992-1998 and 1999-2007. Conservative estimates assumed that women who did not return for IVF would not have the outcome of interest while optimal estimates assumed that these women would have similar outcome rates to those who continued IVF. Main results and the role of chance: A total of 71 551 women commenced IVF treatment during 1992-1998 and an additional 107 347 during 1999-2007. After the third complete IVF cycle (defined as three fresh IVF treatments-including replacement of any surplus frozen-thawed embryos), the conservative CLBR in women who commenced IVF during 1992-1998 was 30.8% increasing to 42.3% during 1999-2007. The optimal CLBRs were 44.6 and 57.1%, respectively. After eight complete cycles the optimal CLBR was 82.4% in the latter time period. The conservative rate for multiple pregnancy per pregnant woman fell from 31.9% during the earlier time period to 26.2% during the latter. Limitations and reason for caution: Linkage of all IVF treatments to individual women was conducted. However, it was not possible to identify with certainty in all cases the episode of ovarian stimulation which generated some of the frozen embryos. Cumulative live birth rates could not be calculated for women who started treatment beyond 2007 as follow-up data were incomplete in some of them. Following a change in legislation in 2008, linked data were only made available for research in women who gave formal consent for this purpose. BMI and ethnicity could not be reported: these demographics are not recorded in the HFEA database. Wider implications of the findings: Our results demonstrate, at a national level, the chances of live birth in couples undergoing a number of complete (fresh and frozen) IVF cycles. They reflect improvements in reproductive technology and a more conservative embryo transfer policy. Although most couples in the UK still do not receive three complete IVF cycles; assuming no barriers to continuation of IVF treatment, around 83% of women receiving IVF would achieve a live birth by the eighth complete cycle, similar to the natural live birth rate in a non-contraception practising population. Our results support the call from NICE to develop consistent IVF policies based on three complete cycles. Study funding/competing interests: This work was funded by a Chief Scientist Office Postdoctoral Training Fellowship in Health Services Research and Health of the Public Research (Ref PDF/12/06). The views expressed here are those of the authors and not necessarily those of the Chief Scientist Office. S.B. reports grants from Chief Scientist Office Scotland during the conduct of the study. His institution has received support from Pharmaceutical companies (for educational seminars), which is not related to the submitted work. D.J.M., A.M. and A.J.L. have no conflicts of interest to declare.
    No preview · Article · Jan 2016 · Human Reproduction
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    Mairead Black · Vikki A Entwistle · Siladitya Bhattacharya · Katie Gillies
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    ABSTRACT: Objective To identify what women report influences their preferred mode of birth after caesarean section. Design Systematic review of qualitative literature using meta-ethnography. Data sources Medline, EMBASE, ASSIA, CINAHL and PsycINFO (1996 until April 2013; updated September 2015). Hand-searched journals, reference lists and abstract authors. Study selection Primary qualitative studies reporting women's accounts of what influenced their preferred mode of birth after caesarean section. Data extraction and synthesis Primary data (quotations from study participants) and authors’ interpretations of these were extracted, compared and contrasted between studies, and grouped into themes to support the development of a ‘line of argument’ synthesis. Results 20 papers reporting the views of 507 women from four countries were included. Distinctive clusters of influences were identified for each of three groups of women. Women who confidently sought vaginal birth after a caesarean section were typically driven by a long-standing anticipation of vaginal birth. Women who sought a repeat caesarean section were strongly influenced by distressing previous birth experiences, and at times, by encouragement from social contacts. Women who were more open to information and professional guidance had fewer strong preconceptions and concerns, and viewed a range of considerations as potentially important. Conclusions Women's attitudes towards birth after caesarean section appear to be shaped by distinct clusters of influences, suggesting that opportunities exist for clinicians to stratify and personalise decision support by addressing relevant ideas, concerns and experiences from the first caesarean section birth onwards.
    Full-text · Article · Jan 2016 · BMJ Open
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    ABSTRACT: STUDY QUESTION Do sex and maternal smoking effects on human fetal anogenital distance (AGD) persist in a larger study and how do these data integrate with the wider literature on perinatal human AGD, especially with respect to sex differences?
    Full-text · Article · Jan 2016 · Human Reproduction
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    ABSTRACT: Maternal smoking is one of the most important modifiable risk factors for low birthweight, which is strongly associated with increased cardiometabolic disease risk in adulthood. Maternal smoking reduces the levels of the methyl donor vitamin B12 and is associated with altered DNA methylation at birth. Altered DNA methylation may be an important mechanism underlying increased disease susceptibility; however, the extent to which this can be induced in the developing fetus is unknown. In this retrospective study, we measured concentrations of cobalt, vitamin B12, and mRNA transcripts encoding key enzymes in the 1-carbon cycle in 55 fetal human livers obtained from 11 to 21 weeks of gestation elective terminations and matched for gestation and maternal smoking. DNA methylation was measured at critical regions known to be susceptible to the in utero environment. Homocysteine concentrations were analyzed in plasma from 60 fetuses. In addition to identifying baseline sex differences, we found that maternal smoking was associated with sex-specific alterations of fetal liver vitamin B12, plasma homocysteine and expression of enzymes in the 1-carbon cycle in fetal liver. In the majority of the measured parameters which showed a sex difference, maternal smoking reduced the magnitude of that difference. Maternal smoking also altered DNA methylation at the imprinted gene IGF2 and the glucocorticoid receptor (GR/NR3C1). Our unique data strengthen studies linking in utero exposures to altered DNA methylation by showing, for the first time, that such changes are present in fetal life and in a key metabolic target tissue, human fetal liver. Furthermore, these data propose a novel mechanism by which such changes are induced, namely through alterations in methyl donor availability and changes in 1-carbon metabolism.
    Full-text · Article · Dec 2015 · BMC Medicine
  • Mairead Black · Siladitya Bhattacharya · Sam Philip · Jane E Norman · David J McLernon
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    ABSTRACT: Importance Planned cesarean delivery comprises a significant proportion of births globally, with combined rates of planned and unscheduled cesarean delivery in a number of regions approaching 50%. Observational studies have shown that offspring born by cesarean delivery are at increased risk of ill health in childhood, but these studies have been unable to adjust for some key confounding variables. Additionally, risk of death beyond the neonatal period has not yet been reported for offspring born by planned cesarean delivery.Objective To investigate the relationship between planned cesarean delivery and offspring health problems or death in childhood.Design, Setting, and Participants Population-based data-linkage study of 321 287 term singleton first-born offspring born in Scotland, United Kingdom, between 1993 and 2007, with follow-up until February 2015.Exposures Offspring born by planned cesarean delivery in a first pregnancy were compared with offspring born by unscheduled cesarean delivery and with offspring delivered vaginally.Main Outcomes and Measures The primary outcome was asthma requiring hospital admission; secondary outcomes were salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, cancer, and death.Results Compared with offspring born by unscheduled cesarean delivery (n = 56 015 [17.4%]), those born by planned cesarean delivery (12 355 [3.8%]) were at no significantly different risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, cancer, or death but were at increased risk of type 1 diabetes (0.66% vs 0.44%; difference, 0.22% [95% CI, 0.13%-0.31%]; adjusted hazard ratio [HR], 1.35 [95% CI, 1.05-1.75]). In comparison with children born vaginally (n = 252 917 [78.7%]), offspring born by planned cesarean delivery were at increased risk of asthma requiring hospital admission (3.73% vs 3.41%; difference, 0.32% [95% CI, 0.21%-0.42%]; adjusted HR, 1.22 [95% CI, 1.11-1.34]), salbutamol inhaler prescription at age 5 years (10.34% vs 9.62%; difference, 0.72% [95% CI, 0.36%-1.07%]; adjusted HR, 1.13 [95% CI, 1.01-1.26]), and death (0.40% vs 0.32%; difference, 0.08% [95% CI, 0.02%-1.00%]; adjusted HR, 1.41 [95% CI, 1.05-1.90]), whereas there were no significant differences in risk of obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, or cancer.Conclusions and Relevance Among offspring of women with first births in Scotland between 1993 and 2007, planned cesarean delivery compared with vaginal delivery (but not compared with unscheduled cesarean delivery) was associated with a small absolute increased risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, and all-cause death by age 21 years. Further investigation is needed to understand whether the observed associations are causal.
    No preview · Article · Dec 2015 · JAMA The Journal of the American Medical Association
  • Abha Maheshwari · Mark Hamilton · Siladitya Bhattacharya

    No preview · Article · Nov 2015 · Reproductive biomedicine online
  • Abha Maheshwari · David McLernon · Siladitya Bhattacharya
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    ABSTRACT: Traditionally, IVF success rates have been reported in terms of live birth per fresh cycle or embryo transfer. With the increasing use of embryo freezing and thawing it is essential that we report not only outcomes following fresh but also those after frozen embryo transfer as a complete measure of success of an IVF treatment. Most people agree that an individual's chance of having a baby following fresh and frozen embryo transfer should be described as cumulative live birth rate. However, views on the most appropriate parameters required to calculate such an outcome have been inconsistent. There is an additional dimension—time for all frozen embryos to be used up by a couple, which can influence the outcome. Given that cumulative live birth rate is generally perceived to be the preferred reporting system in IVF, it is time to have an international consensus on how this statistic is calculated, reported and interpreted by stakeholders across the world.
    No preview · Article · Oct 2015 · Human Reproduction
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    Abha Maheshwari · Mark Hamilton · Siladitya Bhattacharya
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    ABSTRACT: Improved laboratory standards and better culture media have made extended culture to blastocyst stage a reality to identify embryos with maximum implantation potential. The strategy of extended culture has become more popular across the world at a time when regulatory bodies have emphasized the need to increase the uptake of elective single embryo transfer, minimize complications associated with multiple births and aim for a healthy singleton live-birth as the preferred outcome in IVF. New data on perinatal outcomes suggest that pregnancies after embryo transfer at blastocyst stage are associated with a higher risk of preterm delivery, large for gestational age babies, monozygotic twins and altered sex ratio compared with those following embryo transfers at cleavage stage. In addition, concerns have been raised of increased congenital anomalies and epigenetic modifications with embryo transfer at blastocyst stage. Twenty-four years on from the first embryo transfer at blastocyst stage, we examine the reasons for extended embryo culture, evaluate the risks and benefits of this strategy and suggest the need to reconsider this policy in the interests of fetal safety.
    Preview · Article · Oct 2015 · Reproductive biomedicine online
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    ABSTRACT: One in 5 pregnant women is obese but the impact on later health is unknown. We aimed to determine whether maternal obesity during pregnancy associates with increased premature mortality and later life major cardiovascular events. Maternity records of women who gave birth to their first child between 1950 and 1976 (n=18 873) from the Aberdeen Maternity and Neonatal databank were linked to the National Register of Deaths, Scotland and Scottish Morbidity Record. The effect of maternal obesity at first antenatal visit on death and hospital admissions for cardiovascular events was tested using time-to-event analysis with Cox proportional hazard regression to compare outcomes of mothers in underweight, overweight, or obese body mass index (BMI) categories compared with normal BMI. Median follow-up was at 73 years. All-cause mortality was increased in women who were obese during pregnancy (BMI>30 kg/m(2)) versus normal BMI after adjustment for socioeconomic status, smoking, gestation at BMI measurement, preeclampsia, and low birth weight (hazard ratio, 1.35; 95% confidence interval, 1.02-1.77). In adjusted models, overweight and obese mothers had increased risk of hospital admission for a cardiovascular event (1.16; 1.06-1.27 and 1.26; 1.01-1.57) compared with normal BMI mothers. Adjustment for parity largely unchanged the hazard ratios (mortality: 1.43, 1.09-1.88; cardiovascular events overweight: 1.17, 1.07-1.29; and obese: 1.30, 1.04-1.62). In conclusion, maternal obesity is associated with increased risk of premature death and cardiovascular disease. Pregnancy and early postpartum could represent an opportunity for interventions to identify obesity and reduce its adverse consequences.
    No preview · Article · Sep 2015 · Hypertension
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    Valerie L Peddie · Natalie Whitelaw · Grant P Cumming · Siladitya Bhattacharya · Mairead Black
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    ABSTRACT: The United Kingdom (UK) caesarean section (CS) rate is largely determined by reluctance to augment trial of labour and vaginal birth. Choice between repeat CS and attempting vaginal birth after CS (VBAC) in the next pregnancy is challenging, with neither offering clear safety advantages. Women may access online information during the decision-making process. Such information is known to vary in its support for either mode of birth when assessed quantitatively. Therefore, we sought to explore qualitatively, the content and presentation of web-based health care information on birth after caesarean section (CS) in order to identify the dominant messages being conveyed. The search engine Google™ was used to conduct an internet search using terms relating to birth after CS. The ten most frequently returned websites meeting relevant purposive sampling criteria were analysed. Sampling criteria were based upon funding source, authorship and intended audience. Images and written textual content together with presence of links to additional media or external web content were analysed using descriptive and thematic analyses respectively. Ten websites were analysed: five funded by Government bodies or professional membership; one via charitable donations, and four funded commercially. All sites compared the advantages and disadvantages of both repeat CS and VBAC. Commercially funded websites favoured a question and answer format alongside images, 'pop-ups', social media forum links and hyperlinks to third-party sites. The relationship between the parent sites and those being linked to may not be readily apparent to users, risking perception of endorsement of either VBAC or repeat CS whether intended or otherwise. Websites affiliated with Government or health services presented referenced clinical information in a factual manner with podcasts of real life experiences. Many imply greater support for VBAC than repeat CS although this was predominantly conveyed through subtle use of words rather than overt messages, with the exception of the latter being apparent in one site. Websites providing information on birth after CS appear to vary in nature of content according to their funding source. The most user-friendly, balanced and informative websites appear to be those funded by government agencies.
    Full-text · Article · Aug 2015 · BMC Pregnancy and Childbirth

  • No preview · Article · Apr 2015 · Human Reproduction Update
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    Athanasios Papathanasiou · Siladitya Bhattacharya
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    ABSTRACT: Numerous tests and interventions have been proposed for optimizing performance in preparation for in vitro fertilization (IVF) treatment. We critically appraised the available evidence underpinning some of the popular investigations and treatments, including the role of hysteroscopy, laparoscopy, ovarian reserve tests, sperm function tests, as well as the role of lifestyle modifications or surgery for endometriosis, fibroids, and endometrial polyps. We also reviewed the evidence behind novel techniques, such as the use of endometrial injury before IVF. Only a few of the aforementioned modalities are justified based on the available research evidence. Other factors may affect the uptake of a test or intervention before IVF, namely the complexity of the proposed modality, its potential for harm, and its cost-effectiveness. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
    Full-text · Article · Mar 2015 · Seminars in Reproductive Medicine
  • Andrea M. F. Woolner · Siladitya Bhattacharya
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    ABSTRACT: Recent years have witnessed a rise in maternal obesity, which is independently associated with an increased risk of stillbirth. The pathophysiology is unclear, but it is likely related to abnormal placental function, and inflammatory, metabolic and hormonal imbalances in the mother. Obesity is associated with conditions such as diabetes, which can also cause stillbirth. In order to reduce the risk of obesity-associated stillbirth, women of reproductive age should be actively encouraged to optimise their pre-pregnancy weight as the safety of weight loss interventions during pregnancy is unproven. Obese and extremely obese women should be treated as high-risk obstetric patients, with increased antenatal surveillance and specialist input. The postnatal period may be a useful time to provide weight management advice to women to prevent interpregnancy weight gain and reduce the risk of stillbirth in subsequent pregnancies. Copyright © 2014 Elsevier Ltd. All rights reserved.
    No preview · Article · Oct 2014 · Best practice & research. Clinical obstetrics & gynaecology
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    Natalie Whitelaw · Siladitya Bhattacharya · David McLernon · Mairead Black
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    ABSTRACT: Background Repeat caesarean sections make a substantial contribution to the overall caesarean section rate. It is important to understand what influences women to choose this option when the alternative of attempting vaginal birth after caesarean section is available. As many such women use the internet while seeking information on their options, the aim of this study was to assess content of websites on birth after previous caesarean and identify website characteristics which predict content. Methods An internet survey of the forty eight most frequently encountered websites retrieved from a search using various terms relating to birth after caesarean section via a popular search engine was performed. Websites were assessed for their content supportive of either vaginal birth after caesarean (VBAC) or elective repeat caesarean section (ERCS), using the RCOG patient information document, ‘Birth after previous caesarean; Information for You’ as a ‘gold standard’. A simple scoring method which categorised information into either supportive of VBAC (14 facts available) or ERCS (10 facts available) was employed and mean scores compared. Poisson regression analysis was used to assess the extent to which the score was predicted by website funding source, country of origin, author status and intended audience. Results A mean of 42.4% (SD 23.8) of facts supportive of VBAC and 44.8% (SD 25.0) of facts supportive of ERCS were featured across the 48 websites, with corresponding scores in the five most frequently encountered websites being 40.0% (SD 13.9) and 66.0% (SD 20.7). Extent of featured information supportive of ERCS was related to country of origin with the UK having higher scores on average than the US. Conclusions Women searching for internet information on birth after previous caesarean are exposed to incomplete information. Origin of website has a significant effect on website content.
    Full-text · Article · Oct 2014 · BMC Pregnancy and Childbirth
  • Shilpi Pandey · Maureen Porter · Siladitya Bhattacharya
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    ABSTRACT: Background Researchers are being urged to involve patients in the design and conduct of studies in health care with limited insight at present into their needs, abilities or interests. This is particularly true in the field of reproductive health care where many conditions such as pregnancy, menopause and fertility problems involve women who are otherwise healthy.Objective To ascertain the feasibility of involving patients and members of the public in research on women's reproductive health care (WRH).SettingUniversity and tertiary care hospital in north-east Scotland; 37 women aged 18–57.Method Four focus groups and one individual interview were audio-recorded and verbatim transcripts analysed thematically by two researchers using a grounded theory approach.Results and discussionMost participants were interested in WRH, but some participated to promote a health issue of special concern to them. Priorities for research reflected women's personal concerns: endometriosis, polycystic ovary syndrome, menopause, fertility risks of delaying parenthood and early post-natal discharge from hospital. Women were initially enthusiastic about getting involved in research on WRH at the design or delivery stage, but after discussion in focus groups, some questioned their ability to do so or the time available to commit to research. None of the respondents expected payment for any involvement, believing that the experience would be rewarding enough in itself.Conclusions Involving patients and public in research would include different perspectives and priorities; however, recruiting for this purpose would be challenging.
    No preview · Article · Sep 2014 · Health expectations: an international journal of public participation in health care and health policy
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    Irene Kwan · Siladitya Bhattacharya · Angela Kang · Andrea Woolner
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    ABSTRACT: Traditional monitoring of ovarian hyperstimulation during in vitro fertilisation (IVF) and intra-cytoplasmic sperm injection (ICSI) treatment has included transvaginal ultrasonography (TVUS) plus serum estradiol levels to ensure safe practice by reducing the incidence and severity of ovarian hyperstimulation syndrome (OHSS) whilst achieving the good ovarian response needed for assisted reproduction treatment. The need for combined monitoring (using TVUS and serum estradiol) during ovarian stimulation in assisted reproduction is controversial. It has been suggested that combined monitoring is time consuming, expensive and inconvenient for women and that simplification of IVF and ICSI therapy by using TVUS only should be considered.
    Full-text · Article · Aug 2014 · Cochrane database of systematic reviews (Online)
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    ABSTRACT: STUDY QUESTION What is the impact of different age and BMI groups on total investigation and treatment costs in women attending a secondary/tertiary care fertility clinic?
    Full-text · Article · Jul 2014 · Human Reproduction
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    ABSTRACT: BACKGROUND Increasing numbers of children are being conceived by assisted reproductive technology (ART). A number of studies have highlighted an altered epigenetic status in gametes from infertile couples and the possibility of an increased risk of imprinting defects and somatic epigenetic changes in ART conceived children, but the results have been heterogeneous. We performed a systematic review of existing studies to compare the incidence of imprinting disorders and levels of DNA methylation in key imprinted genes in children conceived through in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with those in children conceived spontaneously.
    Full-text · Article · Jun 2014 · Human Reproduction Update

Publication Stats

3k Citations
789.68 Total Impact Points


  • 2000-2016
    • University of Aberdeen
      • • Division of Applied Health Sciences
      • • Obstetrics and Gynaecology
      • • Division of Medical and Dental Education
      • • Institute of Medical Sciences
      Aberdeen, Scotland, United Kingdom
  • 2014
    • University of Oslo
      Kristiania (historical), Oslo, Norway
  • 2008-2014
    • NHS Grampian
      Aberdeen, Scotland, United Kingdom
  • 2013
    • University of London
      Londinium, England, United Kingdom
  • 2012
    • Mansoura University
      • Department of Obstetrics and Gynecology
      Ṭalkha, Muhafazat ad Daqahliyah, Egypt
    • University of São Paulo
      • Department of Obstetrics and Gynecology
      San Paulo, São Paulo, Brazil