First babies conceived with Automated Intracytoplasmic Sperm Injection.

RESEARCH QUESTION: Can an automated sperm injection robot perform Automated Intracytoplasmic Sperm Injection (ICSIA) for use in human IVF? DESIGN: The ICSIA robot automated the sperm injection procedure, including injection pipette advancement, zona pellucida and oolemma penetration with piezo pulses, and pipette removal after sperm release. The robot was first tested in mouse, hamster and rabbit oocytes, and subsequently using discarded human oocytes injected with microbeads. A small clinical pilot trial was conducted with donor oocytes to study the feasibility of the robot in a clinical setting. The ICSIA robot was controlled by engineers with no micromanipulation experience. Results were compared with those obtained with manual ICSI conducted by experienced embryologists. RESULTS: The ICSIA robot demonstrated similar results to the manual procedure in the different animal models tested as well as in the pre-clinical validations conducted in discarded human oocytes. In the clinical validation, 13 out of 14 oocytes injected with ICSIA fertilized correctly versus 16 out of 18 in the manual control; eight developed into good-quality blastocysts versus 12 in the manual control; and four were diagnosed as chromosomally normal versus 10 euploid in the manual control. Three euploid blastocysts from the ICSIA robot group have been transferred into two recipients, which resulted in two singleton pregnancies and two babies born. CONCLUSIONS: The ICSIA robot showed high proficiency in injecting animal and human oocytes when operated by inexperienced personnel. The preliminary results obtained in this first clinical pilot trial are within key performance indicators.

Embryologist agreement when assessing blastocyst implantation probability: is data-driven prediction the solution to embryo assessment subjectivity?

STUDY QUESTION: What is the accuracy and agreement of embryologists when assessing the implantation probability of blastocysts using time-lapse imaging (TLI), and can it be improved with a data-driven algorithm? SUMMARY ANSWER: The overall interobserver agreement of a large panel of embryologists was moderate and prediction accuracy was modest, while the purpose-built artificial intelligence model generally resulted in higher performance metrics. WHAT IS KNOWN ALREADY: Previous studies have demonstrated significant interobserver variability amongst embryologists when assessing embryo quality. However, data concerning embryologists' ability to predict implantation probability using TLI is still lacking. Emerging technologies based on data-driven tools have shown great promise for improving embryo selection and predicting clinical outcomes. STUDY DESIGN, SIZE, DURATION: TLI video files of 136 embryos with known implantation data were retrospectively collected from two clinical sites between 2018 and 2019 for the performance assessment of 36 embryologists and comparison with a deep neural network (DNN). PARTICIPANTS/MATERIALS, SETTING, METHODS: We recruited 39 embryologists from 13 different countries. All participants were blinded to clinical outcomes. A total of 136 TLI videos of embryos that reached the blastocyst stage were used for this experiment. Each embryo's likelihood of successfully implanting was assessed by 36 embryologists, providing implantation probability grades (IPGs) from 1 to 5, where 1 indicates a very low likelihood of implantation and 5 indicates a very high likelihood. Subsequently, three embryologists with over 5 years of experience provided Gardner scores. All 136 blastocysts were categorized into three quality groups based on their Gardner scores. Embryologist predictions were then converted into predictions of implantation (IPG ≥ 3) and no implantation (IPG ≤ 2). Embryologists' performance and agreement were assessed using Fleiss kappa coefficient. A 10-fold cross-validation DNN was developed to provide IPGs for TLI video files. The model's performance was compared to that of the embryologists. MAIN RESULTS AND THE ROLE OF CHANCE: Logistic regression was employed for the following confounding variables: country of residence, academic level, embryo scoring system, log years of experience and experience using TLI. None were found to have a statistically significant impact on embryologist performance at α = 0.05. The average implantation prediction accuracy for the embryologists was 51.9% for all embryos (N = 136). The average accuracy of the embryologists when assessing top quality and poor quality embryos (according to the Gardner score categorizations) was 57.5% and 57.4%, respectively, and 44.6% for fair quality embryos. Overall interobserver agreement was moderate (κ = 0.56, N = 136). The best agreement was achieved in the poor + top quality group (κ = 0.65, N = 77), while the agreement in the fair quality group was lower (κ = 0.25, N = 59). The DNN showed an overall accuracy rate of 62.5%, with accuracies of 62.2%, 61% and 65.6% for the poor, fair and top quality groups, respectively. The AUC for the DNN was higher than that of the embryologists overall (0.70 DNN vs 0.61 embryologists) as well as in all of the Gardner groups (DNN vs embryologists-Poor: 0.69 vs 0.62; Fair: 0.67 vs 0.53; Top: 0.77 vs 0.54). LIMITATIONS, REASONS FOR CAUTION: Blastocyst assessment was performed using video files acquired from time-lapse incubators, where each video contained data from a single focal plane. Clinical data regarding the underlying cause of infertility and endometrial thickness before the transfer was not available, yet may explain implantation failure and lower accuracy of IPGs. Implantation was defined as the presence of a gestational sac, whereas the detection of fetal heartbeat is a more robust marker of embryo viability. The raw data were anonymized to the extent that it was not possible to quantify the number of unique patients and cycles included in the study, potentially masking the effect of bias from a limited patient pool. Furthermore, the lack of demographic data makes it difficult to draw conclusions on how representative the dataset was of the wider population. Finally, embryologists were required to assess the implantation potential, not embryo quality. Although this is not the traditional approach to embryo evaluation, morphology/morphokinetics as a means of assessing embryo quality is believed to be strongly correlated with viability and, for some methods, implantation potential. WIDER IMPLICATIONS OF THE FINDINGS: Embryo selection is a key element in IVF success and continues to be a challenge. Improving the predictive ability could assist in optimizing implantation success rates and other clinical outcomes and could minimize the financial and emotional burden on the patient. This study demonstrates moderate agreement rates between embryologists, likely due to the subjective nature of embryo assessment. In particular, we found that average embryologist accuracy and agreement were significantly lower for fair quality embryos when compared with that for top and poor quality embryos. Using data-driven algorithms as an assistive tool may help IVF professionals increase success rates and promote much needed standardization in the IVF clinic. Our results indicate a need for further research regarding technological advancement in this field. STUDY FUNDING/COMPETING INTEREST(S): Embryonics Ltd is an Israel-based company. Funding for the study was partially provided by the Israeli Innovation Authority, grant #74556. TRIAL REGISTRATION NUMBER: N/A.

Follicle size indicates oocyte maturity and blastocyst formation but not blastocyst euploidy following controlled ovarian hyperstimulation of oocyte donors.

STUDY QUESTION: Is there is an association between follicle size and the quality of oocytes retrieved from them as judged by ability to achieve the blastocyst stage, blastocyst grades and blastocyst ploidy? SUMMARY ANSWER: Although follicle size is a valuable predictor of oocyte maturity and is a significant predictor of the ability of a fertilized oocyte to become a quality blastocyst, the ploidy of each quality blastocyst is not related to the size of the follicle from which its oocyte was retrieved. WHAT IS KNOWN ALREADY: It is unclear whether the oocytes within larger follicles are the best oocytes of the cohort. Although there have been studies examining follicle size in relation to embryo quality, there has been no study relating the incidence of euploidy in embryos to follicle size. STUDY DESIGN, SIZE, DURATION: The purpose of this study was to examine follicle sizes and the oocytes from those follicles (and the embryos that result from those oocytes) to see if there is an association between follicle size and the quality of oocytes as judged by ability to achieve the blastocyst stage, blastocyst grades and blastocyst ploidy. Follicle sizes for oocytes were assessed both as diameters (mm) and as Z values (expressed as their size relative to the mean and standard deviation of that donor's follicular cohort). Comparisons were made using cumulative histograms, rolling averages and receiver operator characteristic (ROC) curves and its AUC. PARTICIPANTS/MATERIALS, SETTING, METHODS: Twenty-two oocyte donors (ages: 24.5 ± 3.5 years) whose recipients would use ICSI for insemination were enrolled in this study. Follicles were aspirated one-at-a-time to be certain that the aspirated oocyte was from the same follicle measured. The follicle measurement (size) was noted in the embryology records. Oocytes were cultured individually throughout their time in the embryology laboratory so that follicle sizes could be uniquely associated with each oocyte. Oocytes and embryos were analyzed according to the size of the follicle from which the oocyte was retrieved. MAIN RESULTS AND THE ROLE OF CHANCE: Three hundred seventeen oocytes (96.1%) had an associated follicle size. Of the oocytes with follicle sizes, 255 (80.4%) had a polar body (MII), and 60 (18.9%) were immature: 31 (9.8%) with a visible germinal vesicle (GV stage) and 29 (9.1%) with neither a polar body nor a visible germinal vesicle (MI). The incidence of MII oocytes was significantly associated with larger follicle size using either mm (ROC's AUC = 0.87; P < 0.0001) or Z values (ROC's AUC = 0.86; P < 0.0001). Among MII oocytes there was no association with follicle size for the appearance of 228 oocytes with two pronuclei (2 PN). Among 2 PN's, the development of 94 quality blastocysts that underwent trophectoderm biopsy (TE Bx) exhibited a significant association with larger follicles using either mm (ROC's AUC = 0.59; P = 0.01) or Z values (ROC's AUC = 0.57; P = 0.01). The use of follicle diameter as a feature to distinguish between fertilized oocytes that would ultimately become blastocysts versus those that would not become blastocysts resulted in an enrichment for blastocyst formation from 20 to 40%. Of the 94 quality blastocysts, 51 were determined by next generation sequencing (NGS) to be euploid.Although oocyte maturity and the incidence of blastocyst formation were associated with follicle size, the incidence of euploidy among biopsied blastocysts was not. Follicles measured by two different methods (mm or Z values) led to predominantly the same conclusions. LIMITATIONS, REASONS FOR CAUTION: This study investigated the relationship between follicle size and measures of oocyte/embryo quality when donors were treated similarly. Therefore, this study does not investigate the effects of triggering and retrieving oocytes when the follicle cohorts are of different sizes or lead follicles are of different sizes. Although no association was found between follicle size and euploid blastocysts, the fact that blastocyst ploidy is not entirely dependent upon oocyte ploidy (e.g. aneuploidies derived from mitotic errors or from the fertilizing sperm) makes it difficult to infer the relationship between follicle diameter and oocyte ploidy. WIDER IMPLICATIONS OF THE FINDINGS: It is confirmed that follicle diameter is predictive of oocyte maturity. However, once oocyte maturity is known, the diameter of the follicle from which the oocyte was retrieved is not instructive. Embryos generated through fertilization and development of the mature oocytes from any observed follicle diameter were equally likely to become euploid blastocysts. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by ReproART: Georgian American Center for Reproductive Medicine. None of the authors declare any actual conflicts of interest. D.H.M. received compensation from ReproART, Biogenetics Corporation and the Sperm and Embryo Bank of New York and honoraria and travel funding from Ferring Pharmaceuticals and from Granata Bio. S.M. received compensation from Cooper Genomics and an honorarium and travel funding from Ferring Pharmaceuticals. L.C. is the founder of LTD Ovamedi, the organization that represents Cooper Genomics in Georgia, and received travel funding from the European Society for Human Reproduction and Embryology. TRIAL REGISTRATION NUMBER: N/A.

First PGT-A using human in vivo blastocysts recovered by uterine lavage: comparison with matched IVF embryo controls†.

STUDY QUESTION: After controlled ovarian stimulation (COS) and IUI, is it clinically feasible to recover in vivo conceived and matured human blastocysts by uterine lavage from fertile women for preimplantation genetic testing for aneuploidy (PGT-A) and compare their PGT-A and Gardner scale morphology scores with paired blastocysts from IVF control cycles? SUMMARY ANSWER: In a consecutive series of 134 COS cycles using gonadotrophin stimulation followed by IUI, uterine lavage recovered 136 embryos in 42% (56/134) of study cycles, with comparable in vivo and in vitro euploidy rates but better morphology in in vivo embryos. WHAT IS KNOWN ALREADY: In vivo developed embryos studied in animal models possess different characteristics compared to in vitro developed embryos of similar species. Such comparative studies between in vivo and in vitro human embryos have not been reported owing to lack of a reliable method to recover human embryos. STUDY DESIGN, SIZE, DURATION: We performed a single-site, prospective controlled trial in women (n = 81) to evaluate the safety, efficacy and feasibility of a novel uterine lavage catheter and fluid recovery device. All lavages were performed in a private facility with a specialized fertility unit, from August 2017 to June 2018. Subjects were followed for 30 days post-lavage to monitor for clinical outcomes and delayed complications. In 20 lavage subjects, a single IVF cycle (control group) with the same ovarian stimulation protocol was performed for a comparison of in vivo to in vitro blastocysts. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Women were stimulated with gonadotrophins for COS. The ovulation trigger was given when there were at least two dominant follicles ≥18 mm, followed by IUI of sperm. Uterine lavage occurred 4-6 days after the IUI. A subset of 20 women had a lavage cycle procedure followed by an IVF cycle (control IVF group). Recovered embryos were characterized morphologically, underwent trophectoderm (TE) biopsy, vitrified and stored in liquid nitrogen. Biopsies were analyzed using the next-generation sequencing technique. After lavage, GnRH antagonist injections were administered to induce menstruation. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 134 lavage cycles were performed in 81 women. Uterine lavage recovered 136 embryos in 56 (42%) cycles. At the time of cryopreservation, there were 40 (30%) multi-cell embryos and 96 (70%) blastocysts. Blastocysts were of good quality, with 74% (70/95) being Gardener grade 3BB or higher grade. Lavage blastocysts had significantly higher morphology scores than the control IVF embryos as determined by chi-square analysis (P < 0.05). This is the first study to recover in vivo derived human blastocysts following ovarian stimulation for embryo genetic characterization. Recovered blastocysts showed rates of chromosome euploidy similar to the rates found in the control IVF embryos. In 11 cycles (8.2%), detectable levels of hCG were present 13 days after IUI, which regressed spontaneously in two cases and declined after an endometrial curettage in two cases. Persistent hCG levels were resolved after methotrexate in three cases and four cases received both curettage and methotrexate. LIMITATIONS, REASON FOR CAUTION: The first objective was to evaluate the feasibility of uterine lavage following ovarian stimulation to recover blastocysts for analysis, and that goal was achieved. However, the uterine lavage system was not completely optimized in our earlier experience to levels that were achieved late in the clinical study and will be expected in clinical service. The frequency of chromosome abnormalities of in vivo and IVF control embryos was similar, but this was a small-size study. However, compared to larger historical datasets of in vitro embryos, the in vivo genetic results are within the range of high-quality in vitro embryos. WIDER IMPLICATIONS OF THE FINDINGS: Uterine lavage offers a nonsurgical, minimally invasive strategy for recovery of embryos from fertile women who do not want or need IVF and who desire PGT, fertility preservation of embryos or reciprocal IVF for lesbian couples. From a research and potential clinical perspective, this technique provides a novel platform for the use of in vivo conceived human embryos as the ultimate benchmark standard for future and current ART methods. STUDY FUNDING/COMPETING INTEREST(S): Previvo Genetics, Inc., is the sole sponsor for the Punta Mita, Mexico, clinical study. S.M. performs consulting for CooperGenomics. J.E.B. and S.A.C. are co-inventors on issued patents and patents owned by Previvo and ownshares of Previvo. S.N. is a co-author on a non-provisional patent application owned by Previvo and holds stock options in Previvo. S.T.N. and M.J.A. report consulting fees from Previvo. S.T.N., S.M., M.V.S., M.J.A., C.N. and J.E.B. are members of the Previvo Scientific Advisory Board (SAB) and hold stock options in Previvo. J.E.B and S. M are members of the Previvo Board of Directors. A.N. and K.C. are employees of Previvo Genetics. L.V.M, T.M.M, J.L.R and S. S have no conflicts to disclose. TRIAL REGISTRATION NUMBER: Protocol Registration and Results System (PRS) Trial Registration Number and Name: Punta Mita Study TD-2104: Clinical Trials NCT03426007.

Aneuploidy and recombination in the human preimplantation embryo. Copy number variation analysis and genome-wide polymorphism genotyping.

RESEARCH QUESTION: What are the incidence and patterns of meiotic trisomies and recombination separately and in relation to each other at the blastocyst stage via single nucleotide polymorphism genotyping combined with array comparative genomic hybridization. DESIGN: Single nucleotide polymorphism microarrays were carried out on a total of 1442 blastocyst stage embryos derived from 268 fertile couples undergoing preimplantation genetic diagnosis for the purposes of avoiding transmittance of known single gene disorders to their offspring; 24-chromosome aneuploidy screening via array comparative genomic hybridization was carried out in parallel. RESULTS: One hundred per cent of meiotic trisomies identified in these embryos were of maternal origin and their incidence increased significantly with advancing maternal age (P < 0.0001). A total of 55.8% of meiotic trisomies were meiosis I-type and 44.2% were meiosis II-type. Certain chromosomes were affected more by meiosis I-type errors, whereas others experienced more meiosis II-type errors. A detailed recombination analysis was carried out for 11,476 chromosomes and 17,763 recombination events were recorded. The average number of recombination sites was 24.0 ± 0.3 for male meiosis and 41.2 ± 0.6 for female meiosis (autosomes only). Sex-specific differences were observed in the locations of recombination sites. Comparative analysis conducted between 190 euploid embryos and 69 embryos presenting maternal meiotic trisomies showed similar recombination rates (P = 0.425) and non-recombinant chromatid rates (P = 0.435) between the two categories; differences, however, were observed when analysing embryos affected with specific maternal meiotic trisomies. CONCLUSIONS: This study yielded unique data concerning recombination and the origin of aneuploidies observed during the first few days of life and provides a novel insight into these important biological processes.

Detection and phasing of single base de novo mutations in biopsies from human in vitro fertilized embryos by advanced whole-genome sequencing.

Currently, the methods available for preimplantation genetic diagnosis (PGD) of in vitro fertilized (IVF) embryos do not detect de novo single-nucleotide and short indel mutations, which have been shown to cause a large fraction of genetic diseases. Detection of all these types of mutations requires whole-genome sequencing (WGS). In this study, advanced massively parallel WGS was performed on three 5- to 10-cell biopsies from two blastocyst-stage embryos. Both parents and paternal grandparents were also analyzed to allow for accurate measurements of false-positive and false-negative error rates. Overall, >95% of each genome was called. In the embryos, experimentally derived haplotypes and barcoded read data were used to detect and phase up to 82% of de novo single base mutations with a false-positive rate of about one error per Gb, resulting in fewer than 10 such errors per embryo. This represents a ∼ 100-fold lower error rate than previously published from 10 cells, and it is the first demonstration that advanced WGS can be used to accurately identify these de novo mutations in spite of the thousands of false-positive errors introduced by the extensive DNA amplification required for deep sequencing. Using haplotype information, we also demonstrate how small de novo deletions could be detected. These results suggest that phased WGS using barcoded DNA could be used in the future as part of the PGD process to maximize comprehensiveness in detecting disease-causing mutations and to reduce the incidence of genetic diseases.

Status of preimplantation genetic testing and embryo selection.

At the recent 2018 PGDIS congress, a review of randomized controlled trials of preimplantation genetic testing for aneuploidies (PGT-A) showed improved ongoing pregnancy rates per transfer in experienced centres and in women aged 35 years and older. Young women produce 40% abnormal embryos (20-60% range), but not all centres see a selection advantage; this indicates the need for more emphasis in improving biopsy and case management. Some chromosome abnormalities are iatrogenic; PGT-A could, therefore, be used as assisted reproductive technology (ART) quality control. Great improvements in non-invasive PGT by testing spent media have been reported, ranging from 80-95% concordance with trophectoderm biopsy, probably precluding the need for biopsy soon. Mosaicism was widely discussed, with PGDIS agreeing to update their guidelines, but continuing to recommend prioritizing euploid, followed by mosaic embryos. Techniques to allow simultaneous single sample analysis of aneuploidy and inherited mutations are improving, but this does not extend to de-novo mutations. Convincing data were presented on the efficacy of using endometrial receptivity tests to improve ART outcomes adjuvant or independently of PGT-A. Imprinting, CRISPR and cloning were also discussed, with a concluding presentation on the first extensive data (aneuploidy and morphology) on in-vivo conceived embryos.

The human sex ratio from conception to birth.

We describe the trajectory of the human sex ratio from conception to birth by analyzing data from (i) 3- to 6-d-old embryos, (ii) induced abortions, (iii) chorionic villus sampling, (iv) amniocentesis, and (v) fetal deaths and live births. Our dataset is the most comprehensive and largest ever assembled to estimate the sex ratio at conception and the sex ratio trajectory and is the first, to our knowledge, to include all of these types of data. Our estimate of the sex ratio at conception is 0.5 (proportion male), which contradicts the common claim that the sex ratio at conception is male-biased. The sex ratio among abnormal embryos is male-biased, and the sex ratio among normal embryos is female-biased. These biases are associated with the abnormal/normal state of the sex chromosomes and of chromosomes 15 and 17. The sex ratio may decrease in the first week or so after conception (due to excess male mortality); it then increases for at least 10-15 wk (due to excess female mortality), levels off after ∼20 wk, and declines slowly from 28 to 35 wk (due to excess male mortality). Total female mortality during pregnancy exceeds total male mortality. The unbiased sex ratio at conception, the increase in the sex ratio during the first trimester, and total mortality during pregnancy being greater for females are fundamental insights into early human development.

Altered levels of mitochondrial DNA are associated with female age, aneuploidy, and provide an independent measure of embryonic implantation potential.

Mitochondria play a vital role in embryo development. They are the principal site of energy production and have various other critical cellular functions. Despite the importance of this organelle, little is known about the extent of variation in mitochondrial DNA (mtDNA) between individual human embryos prior to implantation. This study investigated the biological and clinical relevance of the quantity of mtDNA in 379 embryos. These were examined via a combination of microarray comparative genomic hybridisation (aCGH), quantitative PCR and next generation sequencing (NGS), providing information on chromosomal status, amount of mtDNA, and presence of mutations in the mitochondrial genome. The quantity of mtDNA was significantly higher in embryos from older women (P=0.003). Additionally, mtDNA levels were elevated in aneuploid embryos, independent of age (P=0.025). Assessment of clinical outcomes after transfer of euploid embryos to the uterus revealed that blastocysts that successfully implanted tended to contain lower mtDNA quantities than those failing to implant (P=0.007). Importantly, an mtDNA quantity threshold was established, above which implantation was never observed. Subsequently, the predictive value of this threshold was confirmed in an independent blinded prospective study, indicating that abnormal mtDNA levels are present in 30% of non-implanting euploid embryos, but are not seen in embryos forming a viable pregnancy. NGS did not reveal any increase in mutation in blastocysts with elevated mtDNA levels. The results of this study suggest that increased mtDNA may be related to elevated metabolism and are associated with reduced viability, a possibility consistent with the 'quiet embryo' hypothesis. Importantly, the findings suggest a potential role for mitochondria in female reproductive aging and the genesis of aneuploidy. Of clinical significance, we propose that mtDNA content represents a novel biomarker with potential value for in vitro fertilisation (IVF) treatment, revealing chromosomally normal blastocysts incapable of producing a viable pregnancy.

The cost of a euploid embryo identified from preimplantation genetic testing for aneuploidy (PGT-A): a counseling tool.

PURPOSE: To determine the expected out-of-pocket costs of IVF with preimplantation genetic testing for aneuploidy (PGT-A) to attain a 50%, 75%, or 90% likelihood of a euploid blastocyst based on individual age and AMH, and develop a personalized counseling tool. METHODS: A cost analysis was performed and a counseling tool was developed using retrospective data from IVF cycles intended for PGT or blastocyst freeze-all between January 1, 2014 and August 31, 2017 (n = 330) and aggregate statistics on euploidy rates of > 149,000 embryos from CooperGenomics. Poisson regression was used to determine the number of biopsiable blastocysts obtained per cycle, based on age and AMH. The expected costs of attaining a 50%, 75%, and 90% likelihood of a euploid blastocyst were determined via 10,000 Monte Carlo simulations for each age and AMH combination, incorporating age-based euploidy rates and IVF/PGT-A cost assumptions. RESULTS: The cost to attain a 50% likelihood of a euploid blastocyst ranges from approximately $15,000 U.S. dollars (USD) for younger women with higher AMH values (≥ 2 ng/mL) to > $150,000 for the oldest women (44 years) with the lowest AMH values (< 0.1 ng/mL) in this cohort. The cost to attain a 75% versus 90% likelihood of a euploid blastocyst is similar (~ $16,000) for younger women with higher AMH values, but varies for the oldest women with low AMH values (~ $280,000 and > $450,000, respectively). A typical patient (36-37 years, AMH 2.5 ng/mL) should expect to spend ~ $30,000 for a 90% likelihood of attaining a euploid embryo. CONCLUSIONS: This tool can serve as a counseling adjunct by providing individualized cost information for patients regarding PGT-A.

Clinical implications of mitochondrial DNA quantification on pregnancy outcomes: a blinded prospective non-selection study.

STUDY QUESTION: Can quantification of mitochondrial DNA (mtDNA) in trophectoderm (TE) biopsy samples provide information concerning the viability of a blastocyst, potentially enhancing embryo selection and improving IVF treatment outcomes? SUMMARY ANSWER: This study demonstrated that euploid blastocysts of good morphology, but with high mtDNA levels had a greatly reduced implantation potential. WHAT IS KNOWN ALREADY: Better methods of embryo selection leading to IVF outcome improvement are necessary, as the transfer of chromosomally normal embryos of high morphological grade cannot guarantee the establishment of an ongoing pregnancy. The quantity of mtDNA in embryonic cells has been proposed as a new biomarker of viability-higher levels of mtDNA associated with reduced implantation potential. STUDY DESIGN, SIZE, DURATION: mtDNA was quantified in 199 blastocysts, previously biopsied and shown to be chromosomally normal using preimplantation genetic testing for aneuploidy (PGT-A). These were generated by 174 couples (average female age 37.06 years). All patients underwent IVF in a single clinic. The study took place in a blinded, non-selection manner-i.e. mtDNA quantity was not known at the time of single embryo transfer. The fate of the embryos transferred was subsequently compared to the mtDNA levels measured. PARTICIPANTS/MATERIALS, SETTING, METHODS: Embryos were biopsied at the blastocyst stage. The TE samples obtained were subjected to whole genome amplification followed by comprehensive chromosome analysis via next generation sequencing. The same biopsy specimens were also tested using quantitative PCR, allowing highly accurate mtDNA quantification. After blastocyst transfer, the code used for blinding was broken and analysis undertaken to reveal whether the amount of mtDNA had any association with embryo implantation. MAIN RESULTS AND THE ROLE OF CHANCE: mtDNA analysis of the 199 blastocysts revealed that 9 (5%) contained unusually high levels of mtDNA. All embryo transfers involved a single chromosomally normal blastocyst of good morphology. Of these, 121 (60%) led to ongoing pregnancies, 11(6%) led to biochemical pregnancies, and 10 (5%) spontaneously miscarried. All (100%) of these blastocysts had mtDNA levels considered to be normal/low. The remaining 57 (29%) blastocysts failed to implant. Among these non-viable embryos there were 9 (16%) with unusually high levels of mtDNA. This meant that the ongoing pregnancy rate for morphologically good, euploid blastocysts, with normal/low levels of mtDNA was 64% (121/190). In contrast, the ongoing pregnancy rate for the same type of embryos, but with elevated mtDNA levels, was 0/9 (0%). This difference was highly statistically significant (P < 0.0001). LIMITATIONS REASONS FOR CAUTION: To determine the true extent of any clinical benefits a randomized clinical trial will be necessary. Research is needed to improve understanding of the biology of mtDNA expansion. WIDER IMPLICATIONS OF THE FINDINGS: This is the first investigation to evaluate the clinical impact of increased mtDNA in a prospective blinded manner. Results confirm that embryos with elevated mtDNA rarely implant, supporting its use as a viability biomarker. A total of 64% of euploid blastocysts with normal/low mtDNA implanted versus 60% for the cohort as a whole. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by institutional funding (Reprogenetics UK and Reprogenetics). DW is supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre Programme. None of the authors have any competing interests.

Live birth derived from oocyte spindle transfer to prevent mitochondrial disease.

Mutations in mitochondrial DNA (mtDNA) are maternally inherited and can cause fatal or debilitating mitochondrial disorders. The severity of clinical symptoms is often associated with the level of mtDNA mutation load or degree of heteroplasmy. Current clinical options to prevent transmission of mtDNA mutations to offspring are limited. Experimental spindle transfer in metaphase II oocytes, also called mitochondrial replacement therapy, is a novel technology for preventing mtDNA transmission from oocytes to pre-implantation embryos. Here, we report a female carrier of Leigh syndrome (mtDNA mutation 8993T > G), with a long history of multiple undiagnosed pregnancy losses and deaths of offspring as a result of this disease, who underwent IVF after reconstitution of her oocytes by spindle transfer into the cytoplasm of enucleated donor oocytes. A male euploid blastocyst wasobtained from the reconstituted oocytes, which had only a 5.7% mtDNA mutation load. Transfer of the embryo resulted in a pregnancy with delivery of a boy with neonatal mtDNA mutation load of 2.36-9.23% in his tested tissues. The boy is currently healthy at 7 months of age, although long-term follow-up of the child's longitudinal development remains crucial.

Differences in pregnancy outcomes in donor egg frozen embryo transfer (FET) cycles following preimplantation genetic screening (PGS): a single center retrospective study.

PURPOSE: This study aims to test the hypothesis, in a single-center retrospective analysis, that live birth rates are significantly different when utilizing preimplantation genetic screening (PGS) compared to not utilizing PGS in frozen-thawed embryo transfers in our patients that use eggs from young, anonymous donors. The question therefore arises of whether PGS is an appropriate intervention for donor egg cycles. METHODS: Live birth rates per cycle and live birth rates per embryo transferred after 398 frozen embryo transfer (FET) cycles were examined from patients who elected to have PGS compared to those who did not. Blastocysts derived from donor eggs underwent trophectoderm biopsy and were tested for aneuploidy using array comparative genomic hybridization (aCGH) or next-generation sequencing (NGS), then vitrified for future use (test) or were vitrified untested (control). Embryos were subsequently warmed and transferred into a recipient or gestational carrier uterus. Data was analyzed separately for single embryo transfer (SET), double embryo transfer (DET), and for own recipient uterus and gestational carrier (GC) uterus recipients. RESULTS: Rates of implantation of embryos leading to a live birth were significantly higher in the PGS groups transferring two embryos (DET) compared to the no PGS group (GC, 72 vs. 56 %; own uterus, 60 vs. 36 %). The live birth implantation rate in the own uterus group for SET was higher in the PGS group compared to the control (58 vs. 36 %), and this almost reached significance but the live birth implantation rate for the SET GC group remained the same for both tested and untested embryos. Live births per cycle were nominally higher in the PGS GC DET and own uterus SET and DET groups compared to the non-PGS embryo transfers. These differences almost reached significance. The live birth rate per cycle in the SET GC group was almost identical. CONCLUSIONS: Significant differences were noted only for DET; however, benefits need to be balanced against risks associated with multiple pregnancies. Results observed for SET need to be confirmed on larger series and with randomized cohorts.

The why, the how and the when of PGS 2.0: current practices and expert opinions of fertility specialists, molecular biologists, and embryologists.

STUDY QUESTION: We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0? STUDY FINDING: Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS. WHAT IS KNOWN ALREADY: It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst stage is currently called into question. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: A questionnaire was developed on the three major aspects of PGS 2.0: the Why, with general questions such as PGS 2.0 indications; the How, specifically on genetic analysis methods; the When, on the ideal method and timing of embryo biopsy. Thirty-five colleagues have been selected to address these questions on the basis of their experience with PGS, and demonstrated by peer-reviewed publications, presentations at meetings and participation in the discussion. The first group of experts who were asked about 'The Why' comprised fertility experts, the second group of molecular biologists were asked about 'The How' and the third group of embryologists were asked about 'The When'. Furthermore, the geographical distribution of the experts has been taken into account. Thirty have filled in the questionnaire as well as actively participated in the redaction of the current paper. MAIN RESULTS AND THE ROLE OF CHANCE: The 30 participants were from Europe (Belgium, Germany, Greece, Italy, Netherlands, Spain, UK) and the USA. Array comparative genome hybridization is the most widely used method amongst the participants, but it is slowly being replaced by massive parallel sequencing. Most participants offering PGS 2.0 to their patients prefer blastocyst biopsy. The high efficiency of vitrification of blastocysts has added a layer of complexity to the discussion, and it is not clear whether PGS in combination with vitrification, PGS alone, or vitrification alone, followed by serial thawing and eSET will be the favoured approach. The opinions range from in favour of the introduction of PGS 2.0 for all IVF patients, over the proposal to use PGS as a tool to rank embryos according to their implantation potential, to scepticism towards PGS pending a positive outcome of robust, reliable and large-scale RCTs in distinct patient groups. LIMITATIONS, REASONS FOR CAUTION: Care was taken to obtain a wide spectrum of views from carefully chosen experts. However, not all invited experts agreed to participate, which explains a lack of geographical coverage in some areas, for example China. This paper is a collation of current practices and opinions, and it was outside the scope of this study to bring a scientific, once-and-for-all solution to the ongoing debate. WIDER IMPLICATIONS OF THE FINDINGS: This paper is unique in that it brings together opinions on PGS 2.0 from all different perspectives and gives an overview of currently applied technologies as well as potential future developments. It will be a useful reference for fertility specialists with an expertise outside reproductive genetics. LARGE SCALE DATA: none. STUDY FUNDING AND COMPETING INTERESTS: No specific funding was obtained to conduct this questionnaire.

Causes and estimated incidences of sex-chromosome misdiagnosis in preimplantation genetic diagnosis of aneuploidy.

Preimplantation genetic diagnosis of aneuploidy (PGD-A) with comprehensive chromosome analysis has been known to improve pregnancy outcomes. Accuracy in detecting sex chromosomes becomes important when selecting against embryos at risk for sex-linked disorders. A total of 21,356 PGD-A cycles consisting of day-3 (cleavage) or day-5 (blastocyst) biopsies were received at the same laboratory for PGD-A via fluorescence in situ hybridization (FISH) or array comparative genome hybridization (aCGH) from multiple fertility centres. The misdiagnosis rates were 0.12% (Wilson 95% CI 0.05 to 0.25%) in day-3 FISH cycles, 0.48% (Wilson 95% CI 0.19 to 1.22%) in day-3 aCGH cycles and 0.0% (Wilson 95% CI 0 to 0.26) in day-5 aCGH cycles. Although rare, the likely causative biological event for true misdiagnosis is embryonic XX/XY mosaicism. Reanalysis of 1219 abnormal cleavage-stage research embryos revealed a 73% incidence of minor and major mosaicism. Only four (0.3%) embryos were found to be diploid and contained XX and XY cells that could potentially account for the misdiagnosis of sex. Our investigation identified errors leading to misdiagnosis and their attribution to specific events during PGD-A testing. The reported misdiagnosis rates suggest that PGD-A for sex determination is highly accurate, particularly when using aCGH applied to blastocyst biopsies.

Discrepant diagnosis rate of array comparative genomic hybridization in thawed euploid blastocysts.

PURPOSE: Preimplantation genetic screening (PGS) and diagnosis (PGD) with euploid embryo transfer is associated with improved implantation and live birth rates as compared to routine in vitro fertilization. However, misdiagnosis of the embryo is a potential risk. The purpose of this study was to investigate the clinical discrepant diagnosis rate associated with transfer of trophectoderm-biopsied blastocysts deemed to be euploid via array comparative genomic hybridization (aCGH). METHODS: This is a retrospective cohort study including cycles utilizing PGS or PGD with trophectoderm biopsy, aCGH, and euploid embryo transfer at a large university-based fertility center with known birth outcomes from November 2010 through July 2014 (n = 520). RESULTS: There were 520 embryo transfers of 579 euploid embryos as designated by aCGH. Five discrepant diagnoses were identified. Error rate per embryo transfer cycle was 1.0 %, 0.9 % per embryo transferred, and 1.5 % per pregnancy with a sac. The live birth (LB) error rate was 0.7 % (both sex chromosome errors), and the spontaneous abortion (SAB) error rate was 17.6 % (3/17 products of conception tested, but could range from 3/42 to 7/42). No single gene disorders were mistakenly selected for in any known cases.  CONCLUSIONS: Although aCGH has been shown to be a highly sensitive method of comprehensive chromosome screening, several possible sources of error still exist. While the overall error rate is low, these findings have implications for counseling couples that are contemplating PGS and PGD with aCGH.

Validation of a multiplex genotyping platform using a novel genomic database approach.

PURPOSE: Technological advances now allow for multiplex platforms to simultaneously test many genetic conditions. Typically, such platforms are validated by assaying samples with known genotypes and/or phenotypes and/or with synthetic plasmids; however, these methods have limitations and with the inclusion of rarer diseases and mutations, we can no longer rely solely on them. We used a novel genomic database to validate an expanded genetic carrier screening platform. METHODS: Our expanded carrier screening assay uses the Illumina Infinium iSelect HD Custom genotyping platform to test for 213 genetic diseases by assaying 1,663 pathogenic mutations. We leveraged two Coriell Institute biorepositories for validation: the Subcollection of Heritable Diseases and the 1000 Genomes Project. RESULTS: We measured 12,394 mutation observations in 206 samples, resulting in 246 true positives, 12,147 true negatives, 1 false positive, and no false negatives. Results demonstrated high sensitivity (99.99%) and specificity (99.99%). CONCLUSION: We successfully validated our platform with two biorepositories, demonstrating high sensitivity and specificity. The 1000 Genomes Project samples provided both positive and negative validation for mutations in genes not available through other biorepositories, expanding the depth of validated variants. We recommend including samples from the 1000 Genomes Project in the validation of future multiplex testing platforms.Genet Med advance online publication 30 July 2015Genetics in Medicine (2015); doi:10.1038/gim.2015.101.

Validation of next-generation sequencing for comprehensive chromosome screening of embryos.

Massively parallel genome sequencing, also known as next-generation sequencing (NGS), is the latest approach for preimplantation genetic diagnosis. The purpose of this study was to determine whether NGS can accurately detect aneuploidy in human embryos. Low coverage genome sequencing was applied to trophectoderm biopsies of embryos at the blastocyst stage of development. Sensitivity and specificity of NGS was determined by comparison of results with a previously validated platform, array-comparative genomic hybridization (aCGH). In total, 156 samples (116 were blindly assessed) were tested: 40 samples were re-biopsies of blastocysts where the original biopsy specimen was previously tested for aCGH; four samples were re-biopsies of single blastomeres from embryos previously biopsied at the cleavage stage and tested using aCGH; 18 samples were single cells derived from well-characterized cell lines; 94 samples were whole-genome amplification products from embryo biopsies taken from previous preimplantation genetic screening cycles analysed using aCGH. Per embryo, NGS sensitivity was 100% (no false negatives), and 100% specificity (no false positives). Per chromosome, NGS concordance was 99.20%. With more improvement, NGS will allow the simultaneous diagnosis of single gene disorders and aneuploidy, and may have the potential to provide more detailed insight into other aspects of embryo viability.

Live births following Karyomapping of human blastocysts: experience from clinical application of the method.

The clinical application of a new, widely applicable method known as Karyomapping to carry out a total of 55 clinical cases of preimplantation genetic diagnosis (PGD) for single gene disorders is reported. Conventional polymerase chain reaction (PCR) testing was carried out in parallel to the new method for all cases. Clinical application of Karyomapping in this study resulted in three live births and nine clinical pregnancies out of 20 cases with a transfer. All in all, results presented in this study indicate that Karyomapping is a highly efficient, accurate and robust method for PGD of single gene disorders. Karyomapping can offer a more comprehensive assessment of the region of interest than conventional PCR analysis, allowing for more embryos to receive diagnosis (99.6% versus 96.8%), whereas its wide applicability reduces substantially the time that patients have to wait before starting their in vitro fertilization (IVF) cycle. Nonetheless, inclusion of elements of conventional PCR methodology, such as direct mutation detection, may be required in cases in which the gene of interest is in a region with reduced single nucleotide polymorphism (SNP) coverage (e.g. telomeric regions), when offering PGD for consanguineous couples, or in cases where no samples from additional family members are available.