ESHRE PGT Consortium data collection XXI: PGT analyses in 2018.

STUDY QUESTION: What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years? SUMMARY ANSWER: The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail. WHAT IS KNOWN ALREADY: Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published. STUDY DESIGN SIZE DURATION: The data for PGT analyses performed between 1 January 2018 and 31 December 2018 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform, which is based on genetic analysis and has been in use since 2016. PARTICIPANTS/MATERIALS SETTING METHODS: Data on biopsy method, diagnostic technology, and clinical outcome were submitted by 44 centres. Records with analyses for more than one PGT for monogenic disorders (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR), or with inconsistent data regarding the PGT modality, were excluded. All transfers performed within 2 years after the analysis were included, enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors. MAIN RESULTS AND THE ROLE OF CHANCE: The current data collection from 2018 covers a total of 1388 analyses for PGT-M, 462 analyses for PGT-SR, 3003 analyses for PGT for aneuploidies (PGT-A), and 338 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 19% in 2016-2017 to 33% in 2018), is status quo for PGT-SR (from 30% in 2016-2017 to 33% in 2018) and has become the most used biopsy stage for PGT-A (from 87% in 2016-2017 to 98% in 2018) and for concurrent PGT-M/SR with PGT-A (96%). The use of comprehensive, whole-genome amplification (WGA)-based diagnostic technology showed a small decrease for PGT-M (from 15% in 2016-2017 to 12% in 2018) and for PGT-SR (from 50% in 2016-2017 to 44% in 2018). Comprehensive testing was, however, the main technology for PGT-A (from 93% in 2016-2017 to 98% in 2018). WGA-based testing was also widely used for concurrent PGT-M/SR with PGT-A, as a standalone technique (74%) or in combination with PCR or FISH (24%). Trophectoderm biopsy and comprehensive testing strategies are linked with higher diagnostic efficiencies and improved clinical outcomes per embryo transfer. LIMITATIONS REASONS FOR CAUTION: The findings apply to the data submitted by 44 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript. WIDER IMPLICATIONS OF THE FINDINGS: The Consortium datasets provide a valuable resource for following trends in PGT practice. STUDY FUNDING/COMPETING INTERESTS: The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared. TRIAL REGISTRATION NUMBER: N/A.

ESHRE PGT Consortium data collection XIX-XX: PGT analyses from 2016 to 2017†.

STUDY QUESTION: What are the trends and developments in pre-implantation genetic testing (PGT) in 2016-2017 as compared to previous years? SUMMARY ANSWER: The main trends observed in this 19th and 20th data set on PGT are that trophectoderm biopsy has become the main biopsy stage for PGT for aneuploidies (PGT-A) and that the implementation of comprehensive testing technologies is the most advanced with PGT-A. WHAT IS KNOWN ALREADY: Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 18 data sets and an overview of the first 10 years of data collections have been published. STUDY DESIGN SIZE DURATION: The data for PGT analyses performed between 1 January 2016 and 31 December 2017 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using a new online platform, which is based on genetic analysis as opposed to the former cycle-based format. PARTICIPANTS/MATERIALS SETTING METHODS: Data on biopsy method, diagnostic technology and clinical outcome were submitted by 61 centres. Records with analyses for more than one PGT for monogenic/single gene defects (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR) indication or with inconsistent data regarding the PGT modality were excluded. All transfers performed within 2 years after the analysis were included enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, figures and tables were made by expert co-authors. MAIN RESULTS AND THE ROLE OF CHANCE: The current data collection from 2016 to 2017 covers a total of 3098 analyses for PGT-M, 1018 analyses for PGT-SR, 4033 analyses for PGT-A and 654 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 8-12% in 2013-2015 to 19% in 2016-2017), is status quo for PGT-R (from 22-36% in 2013-2015 to 30% in 2016-2017) and has become the preferential biopsy stage for PGT-A (from 23-36% in 2013-2015 to 87% in 2016-2017). For concurrent PGT-M/SR with PGT-A, biopsy was primarily performed at the blastocyst stage (93%). The use of comprehensive diagnostic technology showed a similar trend with a small increased use for PGT-M (from 9-12% in 2013-2015 to 15% in 2016-2017) and a status quo for PGT-SR (from 36-58% in 2013-2015 to 50% in 2016-2017). Comprehensive testing was the main technology for PGT-A (from 66-75% in 2013-2015 to 93% in 2016-2017) and for concurrent PGT-M/SR with PGT-A (93%). LIMITATIONS REASONS FOR CAUTION: The findings apply to the data submitted by 61 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript. WIDER IMPLICATIONS OF THE FINDINGS: Being the largest data collection on PGT in Europe/worldwide, the data sets provide a valuable resource for following trends in PGT practice. STUDY FUNDING/COMPETING INTERESTS: The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared. TRIAL REGISTRATION NUMBER: N/A.

ESHRE PGT Consortium data collection XVI-XVIII: cycles from 2013 to 2015.

STUDY QUESTION: What are the trends and developments in preimplantation genetic testing (PGT) in 2013-2015 as compared to previous years? SUMMARY ANSWER: The main trends observed in the retrospective data collections 2013-2015, representing valuable data on PGT activity in (mainly) Europe, are the increased application of trophectoderm biopsy at the cost of cleavage stage biopsy and the continuing expansion of comprehensive testing technology in PGT for chromosomal structural rearrangements and for aneuploidies (PGT-SR and PGT-A). WHAT IS KNOWN ALREADY: Since it was established in 1997, the ESHRE PGT Consortium has been collecting data from international PGT centres. To date, 15 data sets and an overview of the first 10 years of data collections have been published. STUDY DESIGN SIZE DURATION: Collection of (mainly) European data by the PGT Consortium for ESHRE. The data for PGT cycles performed between 1 January 2013 and 31 December 2015 were provided by participating centres on a voluntary basis. For the collection of cycle, pregnancy and baby data, separate, pre-designed MS Excel tables were used. PARTICIPANTS/MATERIALS SETTING METHODS: Data were submitted by 59, 60 and 59 centres respectively for 2013, 2014 and 2015 (full PGT Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations, figures and tables were made by expert co-authors. MAIN RESULTS AND THE ROLE OF CHANCE: For data collection XVI/XVII/XVIII, 59/60/59 centres reported data on 8164/9769/11 120 cycles with oocyte retrieval: 5020/6278/7155 cycles for PGT-A, 2026/2243/2661 cycles for PGT for monogenic/single gene defects, 1039/1189/1231 cycles for PGT-SR and 79/59/73 cycles for sexing for X-linked diseases. From 2013 until 2015, the uptake of biopsy at the blastocyst stage was mainly observed in cycles for PGT-A (from 23% to 36%) and PGT-SR (from 22% to 36%), alongside the increased application of comprehensive testing technology (from 66% to 75% in PGT-A and from 36% to 58% in PGT-SR). LIMITATIONS REASONS FOR CAUTION: The findings apply to the 59/60/59 participating centres and may not represent worldwide trends in PGT. Data were collected retrospectively and no details of the follow-up on PGT pregnancies and babies born were provided. WIDER IMPLICATIONS OF THE FINDINGS: Being the largest data collection on PGT worldwide, detailed information about ongoing developments in the field is provided. STUDY FUNDING/COMPETING INTERESTS: The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared. TRIAL REGISTRATION NUMBER: N/A.

Erratum: Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

[This corrects the article DOI: 10.1093/hropen/hoz037.].

Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

STUDY QUESTION: What is the effect of growth velocity (height and weight) in early infancy on metabolic end-points and endothelial function in children born after ART? SUMMARY ANSWER: Neonatal, infant and childhood growth is positively related to blood pressure in 9-year-old IVF/ICSI offspring, while growth in childhood was negatively associated with endothelial function. WHAT IS KNOWN ALREADY: Offspring of pregnancies conceived after ART are at risk for later cardiometabolic risk factors. It is well established that early growth is related to numerous later cardiometabolic risk factors such as high blood pressure. This concept is known as the Developmental Origin of Health and Disease theory. STUDY DESIGN SIZE DURATION: The relation between early growth and later cardiometabolic risk profile was studied in the MEDIUM-KIDS study, a prospective observational cohort study in children born after an IVF/ICSI treatment. In 131 children (48.1% males) at the average age of 9.4 years, cardiometabolic outcomes were assessed and growth data from birth until age 9 years were collected from child welfare centers. PARTICIPANTS/MATERIALS SETTINGS METHODS: The following cardiometabolic outcomes were assessed: blood pressure, skinfolds, lipid spectrum, hair cortisone and glucose and insulin levels. Data on maximum skin perfusion after transdermal delivery of acetylcholine as a measure of endothelial function were collected.Growth charts were obtained electronically from child welfare centers, which offer free consultations and vaccinations to all Dutch children. At these centers, height and weight are recorded at predefined ages. Growth was defined as z-score difference in weight between two time points. Multivariable linear regression analysis was used to model the relation between growth and cardiometabolic outcomes. The following growth windows were -studied simultaneously in each model: 0-1 month, 1-3 months, 3-6 months, 6-11 months, 11-24 months and 2-6 years. The model was adjusted for height growth in all intervals except for 0-1 month. MAIN RESULTS AND THE ROLE OF CHANCE: In multivariable linear regression analyses, multiple growth windows were positively associated with blood pressure, for example growth from 2-6 years was significantly related to systolic blood pressure: B = 4.13, P = 0.005. Maximum skin perfusion after acetylcholine was negatively associated with height-adjusted weight gain from 2 to 6 years: B = -0.09 (log scale), P = 0.03. Several growth windows (weight 1-3 months, 3-6 months, 6-11 months, 11-24 months, 2-6 years) were positively linked with total adiposity. Lipids, glucose tolerance indices and cortisone were not related to growth. LIMITATIONS REASONS FOR CAUTION: This study is of modest size and of observational nature, and we did not include a control group. Therefore, we cannot assess whether the observed associations are causal. It is also not possible to analyze if our observations are specific for, or exacerbated in, the ART population. Ideally, a control group of naturally conceived siblings of IVF/ICSI children should simultaneously be studied to address this limitation and to assess the impact of the ART procedure without the influence of parental (subfertility) characteristics. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study contribute to our understanding of the reported increased risk for hypertension in ART offspring. We speculate that early, accelerated growth may be involved in the reported increased risk for hypertension in ART offspring, with endothelial dysfunction as a possible underlying mechanism. However, additional research into the mechanisms involved is required. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes, grant number #6-FY13-153. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the paper. The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Association of culture medium with growth, weight and cardiovascular development of IVF children at the age of 9 years.

STUDY QUESTION: Is embryo culture media used during an IVF/ICSI treatment associated with differences in growth, body composition and cardiovascular development as determined in 9-year-old singleton IVF children? SUMMARY ANSWER: The choice of in vitro culture medium for human embryos is associated with differences in body weight, BMI, truncal adiposity, waist circumference and waist/hip ratio at the age of 9, while no significant differences were observed in cardiovascular development. WHAT IS KNOWN ALREADY: Children born after IVF/ICSI have an increased risk of low birthweight, which is correlated with a higher risk of cardiovascular diseases. Some studies show that IVF children exhibit a significantly higher systolic and diastolic blood pressure and higher fasting glucose levels compared to naturally conceived children. After alternating assignment to G1™ Version 3 (Vitrolife) or K-SICM (Cook) embryo culture media, birthweight of the resulting children was significantly higher in the Vitrolife group and they remained heavier during the first 2 years of life. STUDY DESIGN, SIZE, DURATION: In this observational cohort study (MEDIUM-KIDS), parents of singletons from a previous study were approached for further follow-up after the ninth birthday of their child. The singletons were born after fresh embryo transfer of cleavage stage embryos resulting from an IVF/ICSI treatment performed between July 2003 and December 2006 in our clinic, when two different culture media were used alternately: either G1™ Version 3 (Vitrolife) or K-SICM (Cook). Follow-up measurements were performed between March 2014 and December 2016. PARTICIPANT/MATERIALS, SETTINGS, METHODS: Parents were invited to attend our clinic with their child for a single visit lasting ~2.5 h. Two experienced clinicians performed all measurements as part of the MEDIUM-KIDS study in a standardized way. Height and weight of the child was measured using calibrated scales, 4-point skinfold thickness measurements were measured in triplicate and waist and hip circumference were measured using a tape measure. The following cardiovascular parameters were measured in a standardized way: blood pressure, heart rate and endothelial function by skin laser-Doppler with iontophoresis using vasodilatory drugs. Cortisol and cortisone concentrations in hair were measured. A blood sample was taken after an overnight fast for insulin, glucose, TSH and lipid analysis. Blood samples of the IVF children were compared with a non-IVF control group. Differences between culture medium groups were analysed by Student's t-test and effects of confounders were analysed using multivariable regression analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 294 eligible children (168 Vitrolife and 126 Cook), 136 children (75 Vitrolife and 61 Cook) participated in the study. Baseline characteristics of the participating children from the Vitrolife and Cook group were similar. Birthweight was higher in the Vitrolife group, in keeping with the full cohort. After correction for confounders, the difference in weight and BMI attributable to culture medium was 1.58 kg (95% CI: 0.01-3.14) and 0.84 kg/m2 (95% CI: 0.02-1.67), respectively, with the Vitrolife children being heavier. Height and height corrected for age and gender (SDS scores) were similar in both groups. Furthermore, waist circumference was significantly higher in the Vitrolife group with a corrected difference of 3.21 cm (95%CI: 0.60-5.81) leading to a 0.03 increase (95% CI: 0.01-0.05) in waist/hip ratio. Subscapular skinfolds combined with suprailiacal skinfolds (defined as truncal adiposity), was also significantly higher in Vitrolife children (adjusted difference 3.44 cm [95% CI: 0.27-6.62]). Both systolic (adj. beta 0.364 [95% CI: -2.129 to 2.856],) and diastolic (adj. beta 0.275 [95% CI: -2.105 to 2.654]) blood pressures (mmHg) were comparable for the two groups. After an overnight fast, cholesterol, glucose, insulin, low and high-density lipoprotein, triglycerides and TSH were normal and similar in the two groups. Endothelial function in the microcirculation was compared by using maximum perfusion units corrected for the baseline value as a measure for vasodilatory capacity. There were no significant differences between the two groups. Cortisol and cortisone concentration in hair samples were comparable. LIMITATIONS, REASONS FOR CAUTION: A limitation of the original study was its pseudo-randomized design. This and the dwindling enthusiasm of families for participation (47.7% after 9 years) prevent us from drawing robust causal conclusions from the observed association. Nevertheless, to date this is oldest cohort of IVF/ICSI children where culture medium was allocated alternatingly and used in a blinded setting, to be studied. We believe that our participants are representative for the full cohort. The current number of participants was sufficient to rule out differences as little as 3 mmHg in systolic and diastolic blood pressures. WIDER IMPLICATIONS OF THE FINDINGS: This study underlines the importance of structured follow-up of IVF/ICSI children to further elucidate possible long-term health effects. Health professionals and culture medium manufacturers should be aware that small changes in culture conditions and culture medium composition for the early embryo can have long-term health effects. The similar cardiovascular results for the two groups are reassuring but the children may still be too young to detect differences in cardiovascular development. Prolonged follow-up and structured investigations up until adulthood are necessary to gain more insight and reassurance in the cardiovascular development of IVF offspring, although long-term follow-up will become more complicated by confounding life-style and environmental factors possibly influencing development. STUDY FUNDING/COMPETING INTEREST(S): The study was financially supported by the March of Dimes (Grant number #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

No effect of IVF culture medium on cognitive development of 9-year-old children.

STUDY QUESTION: Do embryo culture media used during an IVF/ICSI treatment have an effect on cognitive development of singleton IVF children at 9 years of age? SUMMARY ANSWER: Cognitive development of children born after culture in two different embryo culture media is comparable. WHAT IS KNOWN ALREADY: Previously, we have shown that the culture medium used in an IVF/ICSI treatment affects birthweight and weight at 2 years of age after alternating assignment to embryo culture in either K-SCICM (Cook) or G1™ Version 3 (Vitrolife). Children with low birthweight are known to have an increased risk for learning disabilities. Data on cognitive development in general of children born after ART are still conflicting, and the only study reporting on the effects of culture medium on cognitive development shows significant differences in cognitive development between two culture medium groups. STUDY DESIGN SIZE DURATION: In this observational cohort follow-up study (MEDIUM-KIDS), parents of all singletons from our abovementioned study were approached after the ninth birthday of their child to participate in an additional follow-up study. Of the 294 eligible children included in the original study, 119 children (70 Vitrolife and 49 Cook) participated in the current study. PARTICIPANTS/MATERIALS SETTING METHODS: All follow-up measurements were performed between March 2014 and December 2016. CITO (Dutch Central Institute for Test Development) developed the Dutch pupil monitoring system, which involves nationwide independent, standardized, academic achievement score tests to monitor the child's school performance twice a year at fixed time points from third grade onward. The tests include language skills (vocabulary and orthography), mathematics and reading capability and comprehension. Results from the tests performed between third and sixth grades, expressed as ability scores, were obtained from the school. To investigate school performance development over the years, we used a mixed effects multilevel model. The least complex model with the best fit was selected to analyze whether culture medium affects cognitive development in our cohort. The study had enough power to detect a difference in ability score that reflects at least one performance category between the two groups. MAIN RESULTS AND THE ROLE OF CHANCE: No differences were seen in baseline characteristics between participants and non-participants (both parental and children characteristics). For all domains, the random intercept model was used. All analyses showed comparable results for the two culture medium groups. No significant differences were observed for any of the cognitive development domains, even after correction for potential confounders. Parental level of education was higher in the IVF group (45%) if compared to the national average level of education (35%), which most likely explains the higher CITO scores for the IVF children if compared to the National ability scores. LIMITATIONS REASONS FOR CAUTION: A limitation of the study was its pseudo-randomized design and the relatively low participation rate of 40.5%. This and the number of missing data prevent us from drawing robust causal conclusions. However, as this is the first and therewith oldest cohort of children where culture medium was allocated alternatingly and used in a blinded setting, in the same period, with all other conditions identical this study gives up until now the best available evidence. WIDER IMPLICATIONS OF THE FINDINGS: Our study analyzes the effects of culture medium on school performance of children born after IVF/ICSI in a prospective cohort study. Although further research on long-term academic skills and also on behavior is essential, our results are reassuring and should make parents of children born after IVF/ICSI feel comfortable with their children's cognitive development. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes (Grant no. #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Recent developments in genetics and medically assisted reproduction: from research to clinical applications.

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

BRCA1 mutation carriers have a lower number of mature oocytes after ovarian stimulation for IVF/PGD.

PURPOSE: The aim of this study was to determine whether BRCA1/2 mutation carriers produce fewer mature oocytes after ovarian stimulation for in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD), in comparison to a PGD control group. METHODS: A retrospective, international, multicenter cohort study was performed on data of first PGD cycles performed between January 2006 and September 2015. Data were extracted from medical files. The study was performed in one PGD center and three affiliated IVF centers in the Netherlands and one PGD center in Belgium. Exposed couples underwent PGD because of a pathogenic BRCA1/2 mutation, controls for other monogenic conditions. Only couples treated in a long gonadotropin-releasing hormone (GnRH) agonist-suppressive protocol, stimulated with at least 150 IU follicle stimulating hormone (FSH), were included. Women suspected to have a diminished ovarian reserve status due to chemotherapy, auto-immune disorders, or genetic conditions (other than BRCA1/2 mutations) were excluded. A total of 106 BRCA1/2 mutation carriers underwent PGD in this period, of which 43 (20 BRCA1 and 23 BRCA2 mutation carriers) met the inclusion criteria. They were compared to 174 controls selected by frequency matching. RESULTS: Thirty-eight BRCA1/2 mutation carriers (18 BRCA1 and 20 BRCA2 mutation carriers) and 154 controls proceeded to oocyte pickup. The median number of mature oocytes was 7.0 (interquartile range (IQR) 4.0-9.0) in the BRCA group as a whole, 6.5 (IQR 4.0-8.0) in BRCA1 mutation carriers, 7.5 (IQR 5.5-9.0) in BRCA2 mutation carriers, and 8.0 (IQR 6.0-11.0) in controls. Multiple linear regression analysis with the number of mature oocytes as a dependent variable and adjustment for treatment center, female age, female body mass index (BMI), type of gonadotropin used, and the total dose of gonadotropins administered revealed a significantly lower yield of mature oocytes in the BRCA group as compared to controls (p = 0.04). This finding could be fully accounted for by the BRCA1 subgroup (BRCA1 mutation carriers versus controls p = 0.02, BRCA2 mutation carriers versus controls p = 0.50). CONCLUSIONS: Ovarian response to stimulation, expressed as the number of mature oocytes, was reduced in BRCA1 but not in BRCA2 mutation carriers. Although oocyte yield was in correspondence to a normal response in all subgroups, this finding points to a possible negative influence of the BRCA1 gene on ovarian reserve.

Recent developments in genetics and medically-assisted reproduction: from research to clinical applications†‡.

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively-parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Factors affecting the gene expression of in vitro cultured human preimplantation embryos.

STUDY QUESTION: What is the relative effect of common environmental and biological factors on transcriptome changes during human preimplantation development? SUMMARY ANSWER: Developmental stage and maternal age had a larger effect on the global gene expression profile of human preimplantation embryos than the culture medium or oxygen concentration used in in vitro culture. WHAT IS KNOWN ALREADY: Studies on mouse and bovine embryos have shown that different conditions in the in vitro culture of embryos can lead to changes in transcriptome profiles. For humans, an effect of developmental stage on the transcriptome profile of embryos has been demonstrated, but studies on the effect of maternal age or culture conditions are lacking. STUDY DESIGN, SIZE, DURATION: Donated, good quality, day 4 cryopreserved human preimplantation embryos (N = 89) were randomized to be cultured in one of two culture media (G5 medium or HTF medium) and one of two oxygen concentrations (5% or 20%), with stratification for maternal age. Next to these variables, developmental stage after culture was taken into account in the analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Embryos that developed to morula or blastocyst stage during these 2 days whose amplified mRNA passed our quality control criteria for microarray hybridization were individually examined for genome-wide gene expression (N = 37). MAIN RESULTS AND THE ROLE OF CHANCE: Based on the number of differentially expressed genes (DEGs), developmental stage (3519 DEGs) and maternal age (1258 DEGs) had a larger effect on the global gene expression profile of human preimplantation embryos than either tested culture medium (596 DEGs) or oxygen concentration (492 DEGs) used during in vitro culture. Interactions between the factors were found, indicating that culture conditions might have a different effect depending on the developmental stage or the maternal age of the embryos. Affected pathways included metabolism, cell cycle processes and oxidative phosphorylation. LIMITATIONS, REASONS FOR CAUTION: Culture of embryos for only 2 days might have limited the effect on global gene expression by the investigated culture conditions. Earlier stages of development (Day 0 until Day 4) were not analyzed and these embryos might respond differently to the experimental conditions. The freezing and thawing procedures might have had an effect on gene expression. RT-PCR validation was not performed due to scarcity of the material. WIDER IMPLICATIONS OF THE FINDINGS: Our results show that when studying gene expression in single human preimplantation embryos under various experimental conditions, one should take into account the confounding effect of biological variables, such as developmental stage and maternal age. This makes these experiments different from gene expression experiments where these variables can be tightly controlled, for example when using cell lines. STUDY FUNDING/COMPETING INTERESTS: This study received no external funding and there were no competing interests.

Presence of bile acids in human follicular fluid and their relation with embryo development in modified natural cycle IVF.

STUDY QUESTION: Are bile acids (BA) and their respective subspecies present in human follicular fluid (FF) and do they relate to embryo quality in modified natural cycle IVF (MNC-IVF)? SUMMARY ANSWER: BA concentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid (UDCA) derivatives were associated with development of top quality embryos on Day 3 after fertilization. WHAT IS KNOWN ALREADY: Granulosa cells are capable of synthesizing BA, but a potential correlation with oocyte and embryo quality as well as information on the presence and role of BA subspecies in follicular fluid have yet to be investigated. STUDY DESIGN, SIZE, DURATION: Between January 2001 and June 2004, follicular fluid and serum samples were collected from 303 patients treated in a single academic centre that was involved in a multicentre cohort study on the effectiveness of MNC-IVF. PARTICIPANTS/MATERIALS, SETTING, METHODS: Material from patients who underwent a first cycle of MNC-IVF was used. Serum was not stored from all patients, and the available material comprised 156 follicular fluid and 116 matching serum samples. Total BA and BA subspecies were measured in follicular fluid and in matching serum by enzymatic fluorimetric assay and liquid chromatography-mass spectrometry, respectively. The association of BA in follicular fluid with oocyte and embryo quality parameters, such as fertilization rate and cell number, presence of multinucleated blastomeres and percentage of fragmentation on Day 3, was analysed. MAIN RESULTS AND THE ROLE OF CHANCE: Embryos with eight cells on Day 3 after oocyte retrieval were more likely to originate from follicles with a higher level of UDCA derivatives than those with fewer than eight cells (P < 0.05). Furthermore, follicular fluid levels of chenodeoxycholic derivatives were higher and deoxycholic derivatives were lower in the group of embryos with fragmentation compared with those without (each P < 0.05). Levels of total BA were 2-fold higher in follicular fluid compared with serum (P < 0.001), but had no predictive value for oocyte and embryo quality. LIMITATIONS, REASONS FOR CAUTION: Only samples originating from first cycle MNC-IVF were used, which resulted in 14 samples only from women with an ongoing pregnancy, therefore further prospective studies are required to confirm the association of UDCA with IVF pregnancy outcomes. The inter-cycle variability of BA levels in follicular fluid within individuals has yet to be investigated. We checked for macroscopic signs of contamination of follicular fluid by blood but the possibility that small traces of blood were present within the follicular fluid remains. Finally, although BA are considered stable when stored at -20°C, there was a time lag of 10 years between the collection and analysis of follicular fluid and serum samples. WIDER IMPLICATIONS OF THE FINDINGS: The favourable relation between UDCA derivatives in follicular fluid and good embryo development and quality deserves further prospective research, with live birth rates as the end-point. STUDY FUNDING/COMPETING INTERESTS: This work was supported by a grant from the Netherlands Organisation for Scientific Research (VIDI Grant 917-56-358 to U.J.F.T.). No competing interests are reported.

Assisted reproduction treatment and epigenetic inheritance.

BACKGROUND: The subject of epigenetic risk of assisted reproduction treatment (ART), initiated by reports on an increase of children with the Beckwith-Wiedemann imprinting disorder, is very topical. Hence, there is a growing literature, including mouse studies. METHODS: In order to gain information on transgenerational epigenetic inheritance and epigenetic effects induced by ART, literature databases were searched for papers on this topic using relevant keywords. RESULTS: At the level of genomic imprinting involving CpG methylation, ART-induced epigenetic defects are convincingly observed in mice, especially for placenta, and seem more frequent than in humans. Data generally provide a warning as to the use of ovulation induction and in vitro culture. In human sperm from compromised spermatogenesis, sequence-specific DNA hypomethylation is observed repeatedly. Transmittance of sperm and oocyte DNA methylation defects is possible but, as deduced from the limited data available, largely prevented by selection of gametes for ART and/or non-viability of the resulting embryos. Some evidence indicates that subfertility itself is a risk factor for imprinting diseases. As in mouse, physiological effects from ART are observed in humans. In the human, indications for a broader target for changes in CpG methylation than imprinted DNA sequences alone have been found. In the mouse, a broader range of CpG sequences has not yet been studied. Also, a multigeneration study of systematic ART on epigenetic parameters is lacking. CONCLUSIONS: The field of epigenetic inheritance within the lifespan of an individual and between generations (via mitosis and meiosis, respectively) is growing, driven by the expansion of chromatin research. ART can induce epigenetic variation that might be transmitted to the next generation.

Clinical effectiveness of elective single versus double embryo transfer: meta-analysis of individual patient data from randomised trials.

OBJECTIVE: To compare the effectiveness of elective single embryo transfer versus double embryo transfer on the outcomes of live birth, multiple live birth, miscarriage, preterm birth, term singleton birth, and low birth weight after fresh embryo transfer, and on the outcomes of cumulative live birth and multiple live birth after fresh and frozen embryo transfers. DESIGN: One stage meta-analysis of individual patient data. DATA SOURCES: A systematic review of English and non-English articles from Medline, Embase, and the Cochrane Central Register of Controlled Trials (up to 2008). Additional studies were identified by contact with clinical experts and searches of bibliographies of all relevant primary articles. Search terms included embryo transfer, randomised controlled trial, controlled clinical trial, single embryo transfer, and double embryo transfer. Review methods Comparisons of the clinical effectiveness of cleavage stage (day 2 or 3) elective single versus double embryo transfer after fresh or frozen in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatments were included. Trials were included if the intervention differed only in terms of the intended number of embryos to be transferred. Trials that involved only blastocyst (day five) transfers were excluded. RESULTS: Individual patient data were received for every patient recruited to all eight eligible trials (n=1367). A total of 683 and 684 women randomised to the single and double embryo transfer arms, respectively, were included in the analysis. Baseline characteristics in the two groups were comparable. The overall live birth rate in a fresh IVF cycle was lower after single (181/683, 27%) than double embryo transfer (285/683, 42%) (adjusted odds ratio 0.50, 95% confidence interval 0.39 to 0.63), as was the multiple birth rate (3/181 (2%) v 84/285 (29%)) (0.04, 0.01 to 0.12). An additional frozen single embryo transfer, however, resulted in a cumulative live birth rate not significantly lower than the rate after one fresh double embryo transfer (132/350 (38%) v 149/353 (42%) (0.85, 0.62 to 1.15), with a minimal cumulative risk of multiple birth (1/132 (1%) v 47/149 (32%)). The odds of a term singleton birth (that is, over 37 weeks) after elective single embryo transfer was almost five times higher than the odds after double embryo transfer (4.93, 2.98 to 8.18). CONCLUSIONS: Elective single embryo transfer results in a higher chance of delivering a term singleton live birth compared with double embryo transfer. Although this strategy yields a lower pregnancy rate than a double embryo transfer in a fresh IVF cycle, this difference is almost completely overcome by an additional frozen single embryo transfer cycle. The multiple pregnancy rate after elective single embryo transfer is comparable with that observed in spontaneous pregnancies.