The ESHRE PGD Consortium: 10 years of data collection

Preimplantation genetic testing for monogenic disorders (PGT-M) offers an alternative strategy to prevent children from being born with hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes: a retrospective study

BACKGROUND

Preimplantation genetic testing for monogenic disorders (PGT-M) is now widely used as an effective strategy to prevent various monogenic or chromosomal diseases.

MATERIAL AND METHODS

In this retrospective study, couples with a family history of hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes and/or carrying the pathogenic genes underwent PGT-M to prevent children from inheriting disease-causing gene mutations from their parents and developing known genetic diseases. After PGT-M, unaffected (i.e., normal) embryos after genetic detection were transferred into the uterus of their corresponding mothers.

RESULTS

A total of 43 carrier couples with the following hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes underwent PGT-M: Duchenne muscular dystrophy (13 families); methylmalonic acidemia (7 families); spinal muscular atrophy (5 families); infantile neuroaxonal dystrophy and intellectual developmental disorder (3 families each); Cockayne syndrome (2 families); Menkes disease, spinocerebellar ataxia, glycine encephalopathy with epilepsy, Charcot-Marie-Tooth disease, mucopolysaccharidosis, Aicardi-Goutieres syndrome, adrenoleukodystrophy, phenylketonuria, amyotrophic lateral sclerosis, and Dravet syndrome (1 family each). After 53 PGT-M cycles, the final transferable embryo rate was 12.45%, the clinical pregnancy rate was 74.19%, and the live birth rate was 89.47%; a total of 18 unaffected (i.e., healthy) children were born to these families.

CONCLUSIONS

This study highlights the importance of PGT-M in preventing children born with hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes.

Which factors affect the live birth outcome of the first single euploid frozen-thawed blastocyst transfer in couples with balanced chromosomal translocations?

Objective

The objective of this study is to investigate the factors that influence the live birth rate (LBR) of the first single euploid frozen-thawed blastocyst transfer (FBT) cycles after preimplantation genetic testing for structural rearrangements (PGT-SR) in couples with balanced chromosomal translocations (BCT).

Design

Single center, retrospective and observational study.

Methods

A total of 336 PGT-SR and the first single euploid FBT cycles between July 2016 and December 2022 were included in this study. The patients were divided into two groups according to the live birth outcomes. The parameters of the study population, controlled ovarian stimulation cycles, and FBT cycles were analyzed. Multivariable binary logistic regression was performed to find the factors that affected the LBR.

Results

The percentage of blastocysts at developmental stage Day 5 compared to Day 6 (51.8% vs. 30.8%; P<0.001) and with morphology ≥BB compared to

Conclusion

The developmental stage and morphology of blastocyst affect the live birth outcome of the first single euploid FBT in BCT carriers undergoing PGT-SR.

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Key Words

• balanced chromosomal translocations
• euploid
• frozen-thawed blastocyst transfer
• live birth
• preimplantation genetic testing for structural rearrangements (PGT-SR)

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MESH Headings

• Humans
• Female
• Pregnancy
• Retrospective Studies
• Live Birth
• Translocation, Genetic
• Adult
• Embryo Transfer/methods
• Male
• Cryopreservation
• Pregnancy Rate
• Preimplantation Diagnosis/methods
• Birth Rate
• Fertilization in Vitro/methods
• Pregnancy Outcome
• Blastocyst
• Ovulation Induction/methods

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Affiliation(s)

Ruixiao Zhang Reproductive Medicine Center, Henan Provincial People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Zhengzhou University People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Henan University People’s Hospital, Zhengzhou, China
Yahui Hu Reproductive Medicine Center, Henan Provincial People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Zhengzhou University People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Henan University People’s Hospital, Zhengzhou, China
Chenchen Cui Reproductive Medicine Center, Henan Provincial People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Zhengzhou University People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Henan University People’s Hospital, Zhengzhou, China
Cuilian Zhang Reproductive Medicine Center, Henan Provincial People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Zhengzhou University People’s Hospital, Zhengzhou, China Reproductive Medicine Center, Henan University People’s Hospital, Zhengzhou, China

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The effects of photobiomodulation on the improvement of sperm parameters: A review study

The prevalence of male infertility has become a significant clinical concern worldwide, with a noticeable upward trend in recent times. The rates of fertilization and subsequent development of embryos are dependent on many parameters associated with the quality and viability of sperm. Photobiomodulation (PBM) is a promising approach with a great potential for translational applications in the treatment of spermatozoa exhibiting low quality and motility. In this study, a comprehensive analysis of the existing literature, specifically examining the mechanisms of action of PBM has been presented. Our objective was to enhance knowledge in the field of laser light therapy in order to promote the usage of irradiation in clinical settings in a more effective way. Within the realm of reproductive science, the utilization of PBM has been employed to enhance the metabolic processes, motility, and viability of spermatozoa. This is attributed to its advantageous effects on mitochondria, resulting in the activation of the mitochondrial respiratory chain and subsequent synthesis of ATP. This therapeutic approach can be highly advantageous in circumventing the reliance on chemical substances within the culture medium for spermatozoa while also facilitating the viability and motility of spermatozoa, particularly in circumstances involving thawing or samples with significant immotility.

State of the Science and Ethical Considerations for Preimplantation Genetic Testing for Monogenic Cystic Kidney Diseases and Ciliopathies

There is a broad phenotypic spectrum of monogenic polycystic kidney diseases (PKDs). These disorders often involve cilia-related genes and lead to the development of fluid-filled cysts and eventual kidney function decline and failure. Preimplantation genetic testing for monogenic (PGT-M) disorders has moved into the clinical realm. It allows prospective parents to avoid passing on heritable diseases to their children, including monogenic PKD. The PGT-M process involves embryo generation through in vitro fertilization, with subsequent testing of embryos and selective transfer of those that do not harbor the specific disease-causing variant(s). There is a growing body of literature supporting the success of PGT-M for autosomal-dominant and autosomal-recessive PKD, although with important technical limitations in some cases. This technology can be applied to many other types of monogenic PKD and ciliopathies despite the lack of existing reports in the literature. PGT-M for monogenic PKD, like other forms of assisted reproductive technology, raises important ethical questions. When considering PGT-M for kidney diseases, as well as the potential to avoid disease in future generations, there are regulatory and ethical considerations. These include limited government regulation and unstandardized consent processes, potential technical errors, high cost and equity concerns, risks associated with pregnancy for mothers with kidney disease, and the impact on all involved in the process, including the children who were made possible with this technology.

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.

The impact of preimplantation genetic testing on first- and second-trimester maternal serum analyte levels

OBJECTIVE

To determine whether preimplantation genetic testing (PGT) is associated with a change in maternal serum analyte levels in pregnancies conceived via in vitro fertilization (IVF).

METHODS

Retrospective cohort of singleton and twin IVF pregnancies with available first- or second-trimester serum analyte data from 01/2014 to 09/2019. Multiple of the median (MoM) values for free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A (PAPP-A), alpha-fetoprotein (AFP), inhibin A, and unconjugated estriol, were compared between two groups: pregnancies conceived after transfer of PGT screened euploid embryos vs. those conceived after transfer of untested embryos. Multiple linear regression of log MoM values with F test was performed to adjust for potential confounders.

RESULTS

Nine hundred and sixty-two singleton and 165 twin IVF pregnancies with serum analyte data available for analysis were included. PGT was associated with a higher median first- and second-trimester AFP compared to no PGT in singletons (1.23 MoM vs. 1.13 MoM; parameter estimate [PE] 1.08, 95% CI 1.00-1.17, p= .04, and 1.21 MoM vs. 1.07 MoM; PE 1.07, 95% CI 1.01-1.13, p= .01, respectively). PGT was also associated with a lower median PAPP-A compared to no PGT in twins (0.75 MoM vs. 1.18 MoM, PE 0.74, 95% CI 0.60-0.92, p= .006).

CONCLUSIONS

Our data suggest that PGT is associated with higher maternal serum levels of second-trimester AFP in singleton and lower levels of first-trimester PAPP-A in twin pregnancies conceived via IVF.

Simultaneous detection of genomic imbalance in patients receiving preimplantation genetic testing for monogenic diseases (PGT-M)

Background: Preimplantation genetic test for monogenic disorders (PGT-M) has been used to select genetic disease-free embryos for implantation during in vitro fertilization (IVF) treatment. However, embryos tested by PGT-M have risks of harboring chromosomal aneuploidy. Hence, a universal method to detect monogenic diseases and genomic imbalances is required.

Methods: Here, we report a novel PGT-A/M procedure allowing simultaneous detection of monogenic diseases and genomic imbalances in one experiment. Library was prepared in a special way that multiplex polymerase chain reaction (PCR) was integrated into the process of whole genome amplification. The resulting library was used for one-step low-pass whole genome sequencing (WGS) and high-depth target enrichment sequencing (TES).

Results: The TAGs-seq PGT-A/M was first validated with genomic DNA (gDNA) and the multiple displacement amplification (MDA) products of a cell line. Over 90% of sequencing reads covered the whole-genome region with around 0.3–0.4 × depth, while around 5.4%–7.3% of reads covered target genes with >10000 × depth. Then, for clinical validation, 54 embryos from 8 women receiving PGT-M of β-thalassemia were tested by the TAGs-seq PGT-A/M. In each embryo, an average of 20.0 million reads with 0.3 × depth of the whole-genome region was analyzed for genomic imbalance, while an average of 0.9 million reads with 11260.0 × depth of the target gene HBB were analyzed for β-thalassemia. Eventually, 18 embryos were identified with genomic imbalance with 81.1% consistency to karyomapping results. 10 embryos contained β-thalassemia with 100% consistency to conventional PGT-M method.

Conclusion: TAGs-seq PGT-A/M simultaneously detected genomic imbalance and monogenic disease in embryos without dramatic increase of sequencing data output.

Are ovarian responses and the number of transferable embryos different in females and partners of male balanced translocation carriers?

PURPOSE

To compare ovarian response and the number of transferable embryos between women with balanced autosomal translocations and women whose partners carry the translocation (control group). To investigate the predictive value of metaphase II (MII) oocyte number and biopsied embryo number for gaining at lowest one transferable embryo.

DESIGN

We retrospectively analyzed 1942 preimplantation genetic testing for structural rearrangements (PGT-SR) cycles of 1505 balanced autosomal translocation couples over 8 years. All cycles were divided into two subgroups: Robertsonian and reciprocal translocations (ROBT and ReBT). Receiver operator characteristic (ROC) curves were plotted to ascertain a cutoff of MII oocytes and biopsied embryos as predictors of gaining at lowest one transferable embryo.

RESULT

There were no statistical differences in baseline features or ovarian response indicators regarding the number of retrieved/MII oocytes, E2 level on the day of HCG, and ovarian sensitivity index (OSI) between women with balanced autosomal translocations and control group (P > 0.05). A decreased number of transferable embryos were found in women with balanced autosomal translocations regardless of the type of translocation. The cutoff values for gaining at lowest one transferable embryo are 12.5 MII oocytes and 4.5 biopsied embryos, respectively.

CONCLUSION

Women with balanced autosomal translocations have a normal ovarian response, but fewer transferable embryos, meaning that higher gonadotropin (Gn) doses may be required to increase transferable embryos. When fewer than 12.5 MII oocytes or 4.5 blastocysts are obtained in a PGT-SR cycle, couples should be notified that the likelihood of gaining a transferable embryo is low.

PGT for structural chromosomal rearrangements in 300 couples reveals specific risk factors but an interchromosomal effect is unlikely

RESEARCH QUESTION

What factors affect the proportion of chromosomally balanced embryos in structural rearrangement carriers? Is there any evidence for an interchromosomal effect (ICE)?

DESIGN

Preimplantation genetic testing outcomes of 300 couples (198 reciprocal, 60 Robertsonian, 31 inversion and 11 complex structural rearrangement carriers) were assessed retrospectively. Blastocysts were analysed either by array-comparative genomic hybridization or next-generation sequencing techniques. ICE was investigated using a matched control group and sophisticated statistical measurement of effect size (φ).

RESULTS

300 couples underwent 443 cycles; 1835 embryos were analysed and 23.8% were diagnosed as both normal/balanced and euploid. The overall cumulative clinical pregnancy and live birth rates were 69.5% and 55.8%, respectively. Complex translocations and female age (≥35) were found to be risk factors associated with lower chance of having a transferable embryo (P < 0.001). Based on analysis of 5237 embryos, the cumulative de-novo aneuploidy rate was lower in carriers compared to controls (45.6% versus 53.4%, P < 0.001) but this was a 'negligible' association (φ < 0.1). A further assessment of 117,033 chromosomal pairs revealed a higher individual chromosome error rate in embryos of carriers compared to controls (5.3% versus 4.9%), which was also a 'negligible' association (φ < 0.1), despite a P-value of 0.007.

CONCLUSIONS

These findings suggest that rearrangement type, female age and sex of the carrier have significant impacts on the proportion of transferable embryos. Careful examination of structural rearrangement carriers and controls indicated little or no evidence for an ICE. This study helps to provide a statistical model for investigating ICE and an improved personalized reproductive genetics assessment for structural rearrangement carriers.

Using affected embryos to establish linkage phase in preimplantation genetic testing for thalassemia

BACKGROUND

This study aimed to evaluate the ability of next-generation sequencing (NGS) to conduct preimplantation genetic testing (PGT) for thalassemia using affected embryos.

METHODS

This study included data from 36 couples who underwent PGT for thalassemia without probands and relative pedigrees. NGS results were compared with prenatal diagnosis results.

RESULTS

Thirty-six couples (29 α-thalassemia and 7 β-thalassemia) underwent 41 PGT cycles (31 α-thalassemia and 10 β-thalassemia). Analysis using NGS produced conclusive results for all biopsied blastocysts (100%, 217/217). One hundred and sixty (73.7%, 160/217) were unaffected by thalassemia. Preimplantation genetic testing for aneuploidy revealed that 112 (70.0%, 112/160) were euploid. Single blastocysts were transferred into the uteri of 34 women (53 frozen embryo transfer [FET] cycles). Thirty-two cycles resulted in clinical pregnancies, with a clinical pregnancy rate of 60.1% (32/53) per FET cycle. Twenty-two cycles (22 couples) resulted in 23 live births, with a live birth rate of 43.4% (23/53; 3 cycles were ongoing pregnancies). All 25 embryos' prenatal diagnosis results and/or thalassemia gene analyses after delivery were concordant with the NGS-PGT results. Seven embryos (21.9%, 7/32) were miscarried before 12 weeks' gestation, and the abortion villus in four showed a normal karyotype and thalassemia results consistent with the NGS-PGT results. Aborted fetus samples from 3 cycles were not available because the pregnancy lasted less than 5 weeks.

CONCLUSION

NGS can be used to conduct PGT for thalassemia using affected embryos as a reference.

TRIAL REGISTRATION

Retrospectively registered.

Whole Genome Amplification in Preimplantation Genetic Testing in the Era of Massively Parallel Sequencing

Successful whole genome amplification (WGA) is a cornerstone of contemporary preimplantation genetic testing (PGT). Choosing the most suitable WGA technique for PGT can be particularly challenging because each WGA technique performs differently in combination with different downstream processing and detection methods. The aim of this review is to provide insight into the performance and drawbacks of DOP-PCR, MDA and MALBAC, as well as the hybrid WGA techniques most widely used in PGT. As the field of PGT is moving towards a wide adaptation of comprehensive massively parallel sequencing (MPS)-based approaches, we especially focus our review on MPS parameters and detection opportunities of WGA-amplified material, i.e., mappability of reads, uniformity of coverage and its influence on copy number variation analysis, and genomic coverage and its influence on single nucleotide variation calling. The ability of MDA-based WGA solutions to better cover the targeted genome and the ability of PCR-based solutions to provide better uniformity of coverage are highlighted. While numerous comprehensive PGT solutions exploiting different WGA types and adjusted bioinformatic pipelines to detect copy number and single nucleotide changes are available, the ones exploiting MDA appear more advantageous. The opportunity to fully analyse the targeted genome is influenced by the MPS parameters themselves rather than the solely chosen WGA.

The impact of preimplantation genetic testing for aneuploidy on prenatal screening

OBJECTIVES

To determine whether preimplantation genetic testing for aneuploidy (PGT-A) is associated with a reduced risk of abnormal conventional prenatal screening results in singleton pregnancies conceived using in vitro fertilization (IVF).

METHODS

This was a retrospective cohort study of singleton IVF pregnancies conceived from a single tertiary care center between January 2014 and September 2019. Exclusion criteria included mosaic embryo transfers, vanishing twin pregnancies, and cycles with missing outcome data. Two cases of prenatally diagnosed aneuploidy that resulted in early voluntary terminations were also excluded. The primary outcome of abnormal first or second-trimester combined screening results was compared between two groups: pregnancy conceived after transfer of a euploid embryo by PGT-A vs. transfer of an untested embryo. Multivariable backwards-stepwise logistic regression with Firth method was used to adjust for potential confounders.

RESULTS

Of the 419 pregnancies included, 208 (49.6%) were conceived after transfer of a euploid embryo by PGT-A, and 211 (50.4%) were conceived after transfer of an untested embryo. PGT-A was not associated with a lower likelihood of abnormal first-trimester (adjusted OR 1.64, 95% CI 0.82-3.39) or second-trimester screening results (adjusted OR 0.96, 95% CI 0.56-1.64). The incidences of cell-free DNA testing, fetal sonographic abnormalities, genetic counseling, and invasive prenatal diagnostic testing were similar between the two groups.

CONCLUSIONS

Our data suggest that PGT-A is not associated with a change in the likelihood of abnormal prenatal screening results or utilization of invasive prenatal diagnostic testing. Counseling this patient population regarding the importance of prenatal screening and prenatal diagnostic testing, where appropriate, remains essential.

The Special Features of Prenatal and Preimplantation Genetic Counseling in Arab Countries

Genetic counseling services have only recently been introduced in most Arab countries, and their utilization is increasing. Prenatal genetic counseling is essential, particularly in the Arab context, which is characterized by high rates of consanguinity. Nevertheless, little is known about the decisions faced by parents and the factors underlying the complex decision making that must occur when accessing these services in Arab countries. Herein, we performed a narrative review to discuss the reported experiences of parents accessing genetic counseling in the prenatal setting in the 22 Arab countries. We also highlight the different types of decisions encountered and the factors influencing them. We report that: (i) utilization of genetic counseling services varies across different Arab countries; (ii) many factors affect decision making and service utilization, especially religion; and (iii) parents are faced with an array of decisions in the prenatal setting, partly driven by increased utilization of prenatal diagnosis and preimplantation genetic testing in some countries. Our work is the first to highlight the different factors and decisions influencing genetic counseling in Arab countries. Understanding these factors is essential for improving genetic counseling services in the region and helping counselors facilitate informed decision making.

Analysis of clinical outcomes and meiotic segregation modes following preimplantation genetic testing for structural rearrangements using aCGH/NGS in couples with balanced chromosome rearrangement

Purpose

To retrospectively evaluate the effectiveness of PGT‐SR by array comparative genomic hybridization (aCGH) or next‐generation sequencing (NGS) in preventing recurrent miscarriages.

Methods

Thirty one couples with balanced translocation who underwent 68 PGT‐SR cycles between 2012 and 2020 were evaluated. A total of 242 blastocysts were biopsied for aCGH or NGS. The genetically transferable blastocysts were transferred in the subsequent frozen‐thawed single embryo transfer cycle.

Results

The genetically transferable blastocyst rate was 21.2% (51/241). Thirty five genetically transferable blastocysts were transferred into the uterine cavity. The clinical pregnancy rate was 57.1% (20/35), and the ongoing pregnancy rate was 100.0% (20/20). The incidence of interchromosomal effect (ICE) was influenced by ovarian stimulation protocol, female age, and carrier's gender, but dependent on the types of balanced translocation carriers. Furthermore, there was no significant difference in meiotic segregation modes in ovarian stimulation protocols and carrier's gender. Interestingly, the incidence of adjacent‐1 segregation in ≧40 years group increased significantly compared with <35 years group.

Conclusions

For the first time in Japan, we show the effectiveness of PGT‐SR using aCGH or NGS, which enables comprehensive analysis of chromosomes, in the prevention of recurrent miscarriages. Furthermore, our results may support better genetic counseling of balanced translocation carriers for PGT‐SR cycles.

Effect of Blastocyst Morphology and Developmental Rate on Euploidy and Live Birth Rates in Preimplantation Genetic Testing for Aneuploidy Cycles With Single-Embryo Transfer

OBJECTIVE

The aim of this study was to investigate whether blastocyst morphology and developmental rate are associated with euploidy and live birth rates (LBRs) in single euploid frozen-thawed embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

METHODS

This study included 431 preimplantation genetic testing for aneuploidy (PGT-A) cycles followed by 393 FET cycles performed at our center from June 2017 to March 2021. All cycles were analyzed for euploidy based on blastocyst morphology (good, average and poor), developmental stage (day 5 and 6) and maternal age (< 35 and ≥ 35 years old). Multivariate logistic analysis models were used to identify the independent effects of conventional blastocyst morphology, developmental rate and morphological parameters (degree of blastocoele expansion, and grade of inner cell mass and trophectoderm (TE)) on LBRs.

RESULTS

In the group of women aged < 35 years, compared with poor-quality blastocysts, good-quality blastocysts (62.90% vs. 32.46%; odds ratio (OR) 3.163, 95% confidence interval (CI) 2.247-4.451; P < 0.001) and average-quality blastocysts (46.70% vs. 32.46%; OR 1.665, 95% CI 1.287-2.154; P < 0.001) had significantly higher euploidy rates. Additionally, day 5 blastocysts were associated with higher euploidy rates than day 6 blastocysts (49.28% vs. 35.02%; OR 1.506, 95% CI 1.191-1.903; P= 0.001). In the group of women aged ≥ 35 years, euploidy rates were also associated with blastocyst morphology, with 41.86%, 45.65% and 24.39% of good, average and poor-quality embryos, respectively, exhibiting euploidy. However, no relationship was seen between euploidy and blastocyst developmental rate. Multiple logistic regression analysis show that overall blastocyst morphology of euploid embryos was not associated with LBR, only embryos with A-grade TE had significantly higher LBRs than those with C-grade TE (62.71% vs. 45.40%; OR 2.189, 95% CI 1.166-4.109; P=0.015). Similarly, LBRs were significantly higher when day 5 blastocysts were transferred than when day 6 blastocysts were transferred (57.75% vs. 41.67%; OR 2.132, 95% CI 1.370-3.318; P = 0.001).

CONCLUSION

Poor-quality embryos have reduced rates of euploidy. However, blastocyst developmental rate only significantly associates with euploidy rates in women aged younger than 35. Furthermore, only TE grade and blastocyst developmental rate are significantly associated with LBRs following FET cycles.

The clinical application of single-sperm-based single-nucleotide polymorphism haplotyping for PGT of patients with genetic diseases

RESEARCH QUESTION

Is there a simple and effective method for male patients with genetic disorders in families with no identified haplotype and with Robertsonian translocations to avoid the transfer of embryos carrying translocated chromosomes?

DESIGN

Single spermatozoa were separated to identify by next-generation sequencing (NGS) those that were genetically abnormal, to establish a sperm-based single-nucleotide polymorphism (SNP) haplotype. Blastocysts that developed to day 5 or 6 were then biopsied for whole genome amplification and screening for chromosomal aneuploidy. Normal embryos were selected by comparison with a single-sperm-based SNP haplotype and were transferred. The results were verified by second trimester amniocentesis.

RESULTS

Two blastocysts obtained from patients with neurofibroma type 1 (NF1) were found to be normal after NGS according to single-sperm-based SNP haplotype analysis (13 SNP sites). Three and one blastocysts, respectively, were obtained from the patients with Robertsonian translocation. Blastocysts B9 and B7 were found to be normal after NGS according to the single-sperm-based SNP haplotype analysis (12 and 13 SNP sites selected on chromosomes 14 and 22 for the first patient; 12 and 9 SNP sites selected on chromosomes 13 and 14 for the second patient). Successful pregnancies after blastocyst transfer occurred in all three patients. The identification of embryos was verified by mid-trimester amniocentesis. All three patient couples successfully delivered healthy babies.

CONCLUSION

This study preliminarily summarized the process of single-sperm-based SNP haplotyping, which could be applied as preimplantation genetic testing for male patients without identified disease-causing haplotypes and with Robertsonian translocations.

Effect of parental origin and predictors for obtaining a euploid embryo in balanced translocation carriers

RESEARCH QUESTION

What is the effect of parental origin of translocation and predictors for obtaining a euploid embryo in preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) for balanced translocation carriers?

DESIGN

A total of 179 PGT-SR cycles and 614 blastocysts from 123 couples carrying a balanced translocation were retrospectively analysed. Next-generation sequencing (NGS) was performed after trophectoderm biopsy.

RESULTS

There were no differences in ovarian stimulation parameters or PGT-SR outcomes regarding the number of oocytes retrieved (11.95 ± 5.71 versus 11.82 ± 6.26), blastulation rate (0.42 ± 0.27 versus 0.45 ± 0.28), biopsy cancellation rate (11.7% versus 12.9%), the number of blastocysts for biopsy (3.70 ± 2.58 versus 4.04 ± 3.51), or the proportion of euploid embryos (23.80% versus 25.42%), aneuploid embryos (58.10% versus 57.52%) and mosaic embryos (18.10% versus 17.06%) between female carriers and male partner carriers. In a multivariate logistic regression model, the number of blastocysts for biopsy (adjusted odds ratio 1.752; 95% confidence interval 1.359-2.259; P < 0.001) was significantly associated with the chance of obtaining at least one euploid embryo. Receiver operating characteristic analysis with a threshold of 3.5 was conducted to calculate the number of blastocysts required for biopsy to obtain at least one euploid embryo.

CONCLUSIONS

The parental origin of translocation does not significantly affect the PGT-SR outcomes for young balanced translocation carriers. At least 3.5 blastocysts are required to obtain one euploid embryo. Couples should be informed that the probability of obtaining one euploid embryo is low when fewer than 4 blastocysts are obtained in one PGT cycle.

Preimplantation Genetic Testing for Monogenic Conditions: Is Cell-Free DNA Testing the Next Step?

Genetic assessment of an embryo via preimplantation genetic testing (PGT) represents an important reproductive option for couples wanting to try and improve success rates from in vitro fertilisation (IVF) cycles, as well as reduce their risk of having a child born with a genetic condition. Currently, biopsy of the developing embryo prior to transfer allows genetic assessment of an embryo for either chromosome copy number (aneuploidy [PGT-A] or segmental rearrangement [PGT-SR]) or to avoid the transmission of a single gene condition (monogenic conditions [PGT-M]). However, this technology is invasive and commands considerable resources. Non-invasive PGT (niPGT) offers a potential alternate mode of embryonic analysis. Whilst the utility of niPGT-A has been recently explored, there has been limited consideration of niPGT-M as an option for couples at risk of passing on a single gene or chromosomal condition. This review examines the historical and current clinical context of preimplantation embryonic analysis for monogenic conditions, in addition to important considerations surrounding the origin and analysis of cell-free deoxyribose nucleic acid (cfDNA), whether it is sourced via blastocentesis or spent embryonic culture medium (SCM). Future capabilities of this testing modality will almost certainly be enhanced by integration of whole genome sequencing into everyday practice. In addition, the increased utilisation of reproductive carrier screening as part of standard reproductive healthcare will likely result in the identification of a larger high-risk population. As a result, stratification of limited and highly specialised reproductive genetic resources will be required. Prospective parents should continue to be made aware of the limitations of this technology, with prenatal confirmatory testing remaining an essential part of antenatal care in these patients. However, niPGT-M poses an important alternate testing modality for high-risk couples, particularly in the setting of embryos that cannot be biopsied for traditional PGT-M and as demand for this treatment continues to grow.

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 INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Successful Pregnancy Following Preimplantation Genetic Diagnosis of Adrenoleukodystrophy by Detection of Mutation on the ABCD1 Gene

Background

Adrenoleukodystrophy (ALD) is a rare sex-linked recessive disorder that disrupts adrenal gland function and the white matter of the nervous system. According to recent epidemiological statistics, up to this moment, the disease is the most recorded peroxisomal disorder. ABCD1 is a gene related to ALD, with more than 850 unique mutations have been reported. Early diagnosis of the disease would help to consult families with ALD to plan for interventions to prevent passing along the pathogenic mutations to their children.

Material and Methods

A heterozygous ABCD1 gene mutation related to ALD found in a Vietnamese woman was used to design primers for the polymerase chain reaction (PCR) to amplify the segment spanning the mutation. Then, combining sequencing methods for the PCR products, especially Sanger sequencing and next-generation sequencing (NGS), a protocol was developed to detect mutations on the ABCD1 gene to apply for the DNA samples of in-vitro fertilization (IVF) embryos biopsied at the blastocyst stage to screen for pathogenic alleles.

Results

The established protocol for PGD of ALD detected mutant alleles in 5/8 embryos (62.5%), while the remaining 3 embryos (37.5%) did not carry any mutation. One of the 3 embryos was transferred, and a healthy female baby was born after a full-term pregnancy.

Conclusion

The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of ALD but wish to have healthy children.

2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families

This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.

Affected-embryo-based SNP haplotyping with NGS for the preimplantation genetic testing of Marfan syndrome

Marfan syndrome (MFS), an autosomal dominant heritable disease of the connective tissue, is characterized by broad clinical manifestations in the musculoskeletal, cardiovascular, pulmonary, and ocular systems. In this study, a male patient with MFS caused by a heterozygous mutation NM_000138.5(FBN1):c.6037 + 2 T > C in the fibrillin 1 gene (FBN1) underwent preimplantation genetic testing (PGT) by using affected-embryo-based single nucleotide polymorphism (SNP) haplotyping. Multiple displacement amplification was used for whole genome amplification of biopsied trophectoderm cells after controlled ovarian stimulation. Sanger sequencing and next-generation sequencing (NGS) were used to detect the state of FBN1 mutation. A total of 14 blastocysts formed after intracytoplasmic sperm injection were biopsied. After NGS, 60 informative polymorphic SNP markers located upstream and downstream of the FBN1 gene and its pathogenic mutation site were linked to individual alleles. Sanger sequencing further confirmed that 8 blastocysts carried the mutation NM_000138.5(FBN1):c.6037 + 2 T > C, while 6 did not. Four of the non-carriers were euploid verified by copy number variation results. A female infant without MFS was born at 37 weeks gestation after a subsequent frozen embryo transfer. In conclusion, the successful case indicates that SNP haplotyping using sibling embryos as a reference is applicable to PGT in monogenetic diseases.Abbreviations MFS: Marfan syndrome; PGT: preimplantation genetic testing; FBN1: fibrillin 1 gene; NGS: next-generation sequencing; SNP: single nucleotide polymorphism.

Leave the past behind: women's reproductive history shows no association with blastocysts' euploidy and limited association with live birth rates after euploid embryo transfers

STUDY QUESTION

Is there an association between patients' reproductive history and the mean euploidy rates per biopsied blastocysts (m-ER) or the live birth rates (LBRs) per first single vitrified-warmed euploid blastocyst transfers?

SUMMARY ANSWER

Patients' reproductive history (as annotated during counselling) showed no association with the m-ER, but a lower LBR was reported after euploid blastocyst transfer in women with a history of repeated implantation failure (RIF).

WHAT IS KNOWN ALREADY

Several studies have investigated the association between the m-ER and (i) patients' basal characteristics, (ii) ovarian stimulation strategy and dosage, (iii) culture media and conditions, and (iv) embryo morphology and day of full blastocyst development. Conversely, the expected m-ER due to women's reproductive history (previous live births (LBs), miscarriages, failed IVF cycles and transfers, and lack of euploid blastocysts among prior cohorts of biopsied embryos) still needs investigations. Yet, this information is critical to counsel new patients about a first cycle with preimplantation genetic testing for aneuploidy (PGT-A), but even more so after former adverse outcomes to prevent treatment drop-out.

STUDY DESIGN, SIZE, DURATION

This observational study included all patients undergoing a comprehensive chromosome testing (CCT)-based PGT-A cycle with at least one biopsied blastocyst in the period April 2013-December 2019 at a private IVF clinic (n = 2676 patients undergoing 2676 treatments and producing and 8151 blastocysts). m-ER were investigated according to women's reproductive history of LBs: no/≥1, miscarriages: no/1/>1; failed IVF cycles: no/1/2/>2, and implantation failures after previous transfers: no/1/2/>2. Among the 2676 patients included in this study, 440 (16%) had already undergone PGT-A before the study period; the data from these patients were further clustered according to the presence or absence of euploid embryo(s) in their previous cohort of biopsied blastocysts. The clinical outcomes per first single vitrified-warmed euploid blastocyst transfers (n =1580) were investigated according to the number of patients' previous miscarriages and implantation failures.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy without hatching in Day 3, CCT-based PGT-A without reporting segmental and/or putative mitotic (or mosaic) aneuploidies and single vitrified-warmed euploid blastocyst transfer. For statistical analysis, Mann-Whitney U or Kruskal-Wallis tests, as well as linear regressions and generalised linear models among ranges of maternal age at oocyte retrieval were performed to identify significant differences for continuous variables. Fisher's exact tests and multivariate logistic regression analyses were instead used for categorical variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Maternal age at oocyte retrieval was the only variable significantly associated with the m-ER. We defined five clusters (<35 years: 66 ± 31%; 35-37 years: 58 ± 33%; 38-40 years: 43 ± 35%; 40-42 years: 28 ± 34%; and >42 years: 17 ± 31%) and all analyses were conducted among them. The m-ER did not show any association with the number of previous LBs, miscarriages, failed IVF cycles or implantation failures. Among patients who had already undergone PGT-A before the study period, the m-ER did not associate with the absence (or presence) of euploid blastocysts in their former cohort of biopsied embryos. Regarding clinical outcomes of the first single vitrified-warmed euploid blastocyst transfer, the implantation rate was 51%, the miscarriage rate was 14% and the LBR was 44%. This LBR was independent of the number of previous miscarriages, but showed a decreasing trend depending on the number of previous implantation failures, reaching statistical significance when comparing patients with >2 failures and patients with no prior failure (36% versus 47%, P < 0.01; multivariate-OR adjusted for embryo quality and day of full blastocyst development: 0.64, 95% CI 0.48-0.86, P < 0.01). No such differences were shown for previous miscarriage rates.

LIMITATIONS, REASONS FOR CAUTION

The sample size for treatments following a former completed PGT-A cycle should be larger in future studies. The data should be confirmed from a multicentre perspective. The analysis should be performed also in non-PGT cycles and/or including patients who did not produce blastocysts, in order to investigate a putative association between women's reproductive history with outcomes other than euploidy and LBRs.

WIDER IMPLICATIONS OF THE FINDINGS

These data are critical to counsel infertile couples before, during and after a PGT-A cycle, especially to prevent treatment discontinuation due to previous adverse reproductive events. Beyond the 'maternal age effect', the causes of idiopathic recurrent pregnancy loss (RPL) and RIF are likely to be endometrial receptivity and selectivity issues; transferring euploid blastocysts might reduce the risk of a further miscarriage, but more information beyond euploidy are required to improve the prognosis in case of RIF.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Utilization of preimplantation genetic testing for monogenic disorders

OBJECTIVE

To determine the rate of utilization, factors influencing the decision-making process, and patient satisfaction with preimplantation genetic diagnosis for monogenic disorders (PGT-M).

DESIGN

Survey study.

SETTING

Academic center.

PATIENT(S)

Genetically at-risk patients seen for PGT-M consultation between January 2010 and 2018.

INTERVENTION(S)

Electronic survey including demographics, genetic history, consultation experience, decision-making process, and satisfaction with PGT-M process.

MAIN OUTCOME MEASURE(S)

Rate of utilization of PGT-M, importance of decision-making factors, and satisfaction with PGT-M process.

RESULT(S)

Among survey respondents (n = 49), the rate of utilization of PGT-M after consultation was 89.8%. Ninety-three percent of participants decided whether to pursue PGT-M within 3 months of consultation. Factors that were considered most important to this decision-making process included information provided at consultation, accuracy of test results after PGT-M, avoidance of suffering of an affected child, and ability to avoid termination of an affected pregnancy. Key barriers to utilization included financial burden and overall complexity of the in vitro fertilization (IVF)/PGT-M process. Of those utilizing PGT-M (n = 44), 72.1% had at least one live birth or were pregnant during the study period. Satisfaction with PGT-M was high, and most couples would use IVF/PGT-M for a future pregnancy (84.1%). Participants with a live birth were more satisfied with the PGT-M process than those who had no live birth.

CONCLUSION(S)

Most patients seeking consultation for PGT-M were likely to pursue this technology despite financial burden and complexity of the process. Exploring factors that influence patient decision-making regarding PGT-M is important for tailoring the consultation and optimizing the overall experience.

Embryo biopsy and perinatal outcomes of singleton pregnancies: an analysis of 16,246 frozen embryo transfer cycles reported in the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System

BACKGROUND

Preimplantation genetic testing is commonly performed by removing cells from the trophectoderm, the outer layer of the blastocyst, which subsequently forms the placenta. Because preimplantation genetic testing removes the cells that are destined to form the placenta, it is possible that preimplantation genetic testing could be associated with an increased risk for adverse outcomes associated with abnormal placentation. Despite the increasing utilization of preimplantation genetic testing, few studies have investigated the perinatal outcomes, with published studies yielding contradictory findings and using small sample sizes.

OBJECTIVE

This study aimed to compare the perinatal outcomes of singleton pregnancies conceived following frozen embryo transfer of a single, autologous blastocyst either with or without preimplantation genetic testing.

STUDY DESIGN

This was a retrospective analysis of autologous frozen embryo transfer cycles that led to singleton live births per the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System, including cycles initiated between 2014 and 2015. The perinatal outcomes, including birthweight, Z-score, small for gestational age, large for gestational age, macrosomia, and preterm birth, were compared between pregnancies with or without preimplantation genetic testing. We conducted multivariable linear regression analyses for the birthweight and Z-score and logistic regression for the binary outcomes. A false discovery rate was adjusted to decrease the type I error from multiple hypothesis testing.

RESULTS

Of the 16,246 frozen embryo transfers resulting in singleton births included in this analysis, 6244 involved the transfer of a single blastocyst that had undergone preimplantation genetic testing, and the remainder (n=10,002) involved the transfer of a single blastocyst that had not undergone a biopsy. When compared with the women from the nonpreimplantation genetic testing group, the average maternal age (35.8±4.1 vs 33.7±3.9; P<.001) and prevalence of prior spontaneous abortion (37.3% vs 27.7%; P<.001) were higher among women from the preimplantation genetic testing group. Bivariate analysis revealed a higher prevalence of small-for-gestational-age newborns (4.8% vs 4.0%; P=.008) and premature delivery (14.1% vs 12.5%; P=.005) and a lower prevalence of large-for-gestational-age newborns (16.3% vs 18.2%; P=.003) and macrosomia (11.1% vs 12.4%; P=.013) among the preimplantation genetic testing pregnancies. Multivariate regression analyses, adjusting for the year of transfer, maternal age, maternal body mass index, smoking status (3 months before the treatment cycle), obstetrical histories (full-term birth, preterm birth, and spontaneous abortion), infertility diagnosis, and infant sex suggested a significantly increased odds of preterm birth (adjusted odds ratio, 1.20; 95% confidence interval, 1.09-1.33; P<.001) from preimplantation genetic testing blastocysts. Birthweight (-14.63; 95% confidence interval, -29.65 to 0.38; P=.056), birthweight Z-score (-0.03; 95% confidence interval, -0.06 to 0.00; P=.081), and odds of small-for-gestational-age newborns (adjusted odds ratio, 1.17; 95% confidence interval, 0.99-1.38; P=.066), large-for-gestational-age newborns (adjusted odds ratio, 0.96; 95% confidence interval, 0.88-1.06; P=.418), and macrosomia (adjusted odds ratio, 0.96; 95% confidence interval, 0.85-1.07; P=.427) did not differ between the frozen transfer cycles with or without preimplantation genetic testing in the analysis adjusted for the confounders. Subgroup analysis of the cycles with a stated infertility diagnosis (n=14,285) yielded consistent results.

CONCLUSION

Compared with frozen embryo transfer cycles without preimplantation genetic testing, the frozen embryo transfer cycles with preimplantation genetic testing was associated with a small increase in the likelihood of preterm birth. Although the increase in the risk for prematurity was modest in magnitude, further investigation is warranted.

The status of preimplantation genetic testing in the UK and USA

STUDY QUESTION

Has the number of preimplantation genetic testing (PGT) cycles in the UK and USA changed between 2014 and 2016?

SUMMARY ANSWER

From 2014 to 2016, the number of PGT cycles in the UK has remained the same at just under 2% but in the USA has increased from 13% to 27%.

WHAT IS KNOWN ALREADY

PGT was introduced as a treatment option for couples at risk of transmitting a known genetic or chromosomal abnormality to their child. This technology has also been applied as an embryo selection tool in the hope of increasing live birth rates per transfer. ART cycles are monitored in the UK by the Human Fertilisation and Embryology Authority (HFEA) and in the USA by the Society for Assisted Reproductive Technology (SART). Globally, data are monitored via the ESHRE PGT Consortium.

STUDY DESIGN, SIZE, DURATION

This cross-sectional study used the HFEA and SART databases to analyse PGT cycle data and make comparisons with IVF data to examine the success of and changes in patient treatment pathways. Both data sets were analysed from 2014 to 2016. The UK data included 3385 PGT cycles and the USA data included 94 935 PGT cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Following an extensive review of both databases, filters were applied to analyse the data. An assessment of limitations of each database was also undertaken, taking into account data collection by the ESHRE PGT Consortium. In the UK and USA, the publicly available information from these datasets cannot be separated into different indications.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of PGT cycles as a total of ART procedures has remained the same in the UK but increased annually in the USA from 13% to 27%. Between 2014 and 2016 inclusive, 3385 PGT cycles have been performed in the UK, resulting in 1074 PGT babies being born. In the USA 94 935 PGT cycles have been performed, resulting in 26 822 babies being born. This gave a success rate per egg collection for PGT of 32% for the UK and 28% for the USA. Analysis of the data by maternal age shows very different patient populations between the UK and USA. These differences may be related to the way PGT is funded in the UK and USA and the lack of HFEA support for PGT for aneuploidy.

LIMITATIONS, REASONS FOR CAUTION

Data reported by the HFEA and SART have different limitations. As undertaken by the ESHRE PGT Consortium, both data sets should separate PGT data by indication. Although the HFEA collects data from all IVF clinics in the UK, SART data only represent 83% of clinics in the USA.

WIDER IMPLICATIONS OF THE FINDINGS

Worldwide, a consistent reporting scheme is required in which success rates can convey the effectiveness of PGT approaches for all indications.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained and there are no competing interests to declare that are directly related to this project. Joyce Harper is the director of the Embryology and PGD Academy, which offers education in these fields.

Utilization of preimplantation genetic testing in the USA

PURPOSE

To evaluate the use of preimplantation genetic testing (PGT) and live birth rates (LBR) in the USA from 2014 to 2017 and to understand how PGT is being used at a clinic and state level.

METHODS

This study accessed SART data for 2014 to 2017 to determine LBR and the CDC for years 2016 and 2017 to identify PGT usage. Primary cycles included only the first embryo transfer within 1 year of an oocyte retrieval; subsequent cycles included transfers occurring after the first transfer or beyond 1 year of oocyte retrieval.

RESULTS

In the SART data, the number of primary PGT cycles showed a significant monotonic annual increase from 18,805 in 2014 to 54,442 in 2017 (P = 0.042) and subsequent PGT cycles in these years increased from 2946 to 14,361 (P = 0.01). There was a significant difference in primary PGT cycle use by age, where younger women had a greater percentage of PGT treatment cycles than older women. In both PGT and non-PGT cycles, the LBR per oocyte retrieval decreased significantly from 2014 to 2017 (P<0001) and younger women had a significantly higher LBR per oocyte retrieval compared to older women (P < 0.001). The CDC data revealed that in 2016, just 53 (11.4%) clinics used PGT for more than 50% of their cycles, which increased to 99 (21.4%) clinics in 2017 (P< 0.001).

CONCLUSIONS

A growing number of US clinics are offering PGT to their patients. These findings support re-evaluation of the application for PGT.

Impact of preimplantation genetic testing for aneuploidies (PGT-A) on first trimester biochemical markers - PAPP-A (placenta-associated plasma protein) and free β-hCG (human chorionic gonadotropin)

OBJECTIVE

The objective of the study was to study the effect of preimplantation genetic testing for aneuploidies (PGT-A) performed at blastocyst stage on the levels of first trimester biomarkers.

METHODS

This is an observational, collaborative, retrospective study. Seven hundred and twenty-eight patients were included in the study. Patients were with singleton pregnancies resulting from either natural conception (NC), or assisted reproductive techniques (ARTs) with PGT-A and frozen embryo transfer (FET) (ART/PGT-A/FET) or after ART without PGT-A and fresh ET (ART/no PGT-A/fresh ET) or FET (ART/no PGT-A/FET), who had first trimester combined screening test between 11 and 14 gestational weeks. They were stratified into four groups: group A (ART/PGT-A/FET) - 143 patients; group B (ART/no PGT-A/FET) - 100 patients; group C (ART/no PGT-A/fresh ET) - 346 patients, and group D (NC) - 139 patients.

RESULTS

Statistically significant differences among the examined groups were observed for maternal age, BMI, ethnicity, and parity. The median placenta-associated plasma protein (PAPP-A) was lowest in the group with ART/PGT-A/FET and the highest result was obtained in the group with ART/no PGT-A/FET. Statistically significant difference in the median PAPP-A levels was identified among the examined groups (p = .0186). When a subgroup analysis was performed, a statistically significant difference was observed in the median PAPP-A between ART/PGT-A/FET group versus ART/no PGT-A/FET group (p = .01) and NC versus ART/no PGT-A/FET (p = .01). A similar trend toward statistical significance was noted when comparing NC versus ART/no PGT-A/fresh ET (p = .06). Multivariate analysis elucidated that when age is present in the model, the effect of any method of conception or testing for aneuploidy disappears. The other factors (BMI, ethnicity, and parity) do not influence the levels of PAPP-A. The lowest median free human chorionic gonadotropin (β-HCG) was recorded in the NC group and the highest result was identified in the group with IVF/PGT-A/FET. No statistically significant difference was observed in the median concentration levels of free β-hCG among the compared groups (p = .5789) and when subgroup analysis was performed (p>.05). The normality of the distribution of variables was analyzed by the Kolmogorov-Smirnov test and the median PAPP-A and free βhCG concentration difference by the Wilcoxon rank-sum test with nonparametric ANOVA.

CONCLUSIONS

Testing for aneuploidy (PGT-A) and the decision to transfer either fresh or cryopreserved embryos (ET) appear not to affect the levels of first trimester biochemical markers. The findings of the present study should be a baseline for future studies and could be used to improve the antenatal screening counseling for women with ART pregnancies and PGT-A.

Maternal and neonatal outcomes in pregnancies conceived after preimplantation genetic testing

OBJECTIVE

To determine whether preimplantation genetic testing (PGT) is associated with an increase in adverse maternal or neonatal outcomes in singleton and twin live births conceived via in vitro fertilization (IVF).

METHOD

Retrospective cohort of live births resulting from IVF within a university health system between January 2014 and August 2019. Adverse maternal outcomes (e.g., hypertensive disorders of pregnancy, abnormal placentation, and preterm birth), and adverse neonatal outcomes were compared in singleton and twin pregnancies conceived after transfer of one or two PGT-screened euploid embryos versus untested embryos in separate analyses. Multivariate backwards-stepwise logistic regression was used to adjust for potential confounders.

RESULTS

Of 1160 live births, 539 (46.5%) resulted from PGT-screened embryos, 1015 (87.5%) were singletons, and 145 (12.5%) were twins. After adjusting for potential confounders, there were no significant differences between the two groups with respect to hypertensive disorders of pregnancy, fetal growth restriction, preterm birth, and adverse neonatal outcomes in both analyses, as well as abnormal placentation for singletons.

CONCLUSION

Our data suggest that IVF with PGT is not associated with an increased risk of adverse maternal or neonatal outcomes compared to IVF without PGT. Further research utilizing larger cohorts are needed before drawing definitive conclusions.

The Effectiveness of Next-Generation Sequencing-Based Preimplantation Genetic Testing for Balanced Translocation Couples

The purpose of this study was to evaluate the effectiveness of next-generation sequencing (NGS)-based preimplantation genetic testing (PGT) for balanced translocation carriers to identify normal/balanced blastocysts and to measure pregnancy outcomes following euploid embryo transfer. We enrolled 75 couples with a balanced translocation who underwent 83 PGT cycles (58 cycles for carriers with reciprocal translocations and 25 cycles for carriers with Robertsonian translocations) and 388 blastocysts were diagnosed. Moreover, we transferred single euploid blastocysts through frozen embryo transfer and calculated the biochemical pregnancy, clinical pregnancy, miscarriage, and ongoing pregnancy rates per embryo transfer cycle. Despite a mean maternal age of 29.8 years and mean of 4.34 embryos biopsied, there was a 32.8% chance of recording no chromosomally normal/balanced embryos for reciprocal translocation carriers. The proportion of normal/balanced embryos was significantly higher (44.1 vs. 27.8%) in Robertsonian translocation carriers than in reciprocal translocation carriers. Female carriers had a significantly lower (23.3 vs. 42.4%, 34.7 vs. 54.7%, respectively) percentage of normal/balanced embryos than male carriers, regardless of the translocation. After transfering single blastocysts, we obtained a 64.4% clinical pregnancy rate per transfer, and the clinical miscarriage rate was 5.7%. Amniocentesis results showed that all karyotypes of the fetuses were consistent with PGT results. The clinical outcomes are probably not influenced by the type of translocation, maternal age, and blastocyst morphology following the transfer of euploid blastocysts. Therefore, we conclude that NGS-based PGT is an efficient method for analyzing balanced translocation carriers, and aneuploidy screening had good clinical outcomes.

Successful four-factor preimplantation genetic testing: α- and β-thalassemia, human leukocyte antigen typing, and aneuploidy screening

Our study established an effective next-generation sequencing (NGS) protocol for four-factor preimplantation genetic testing (PGT) using  α- and β-thalassemia, human leukocyte antigen (HLA) typing, and aneuploidy screening. Three couples, in whom both partners were α- and β-double thalassemia carriers, underwent PGT between 2016 and 2018. These individuals sought an opportunity for hematopoietic stem cell transplantation to save their children from β-thalassemia major. A total of 35 biopsied trophectoderm samples underwent multiple displacement amplification (MDA). PGT for α- and β-thalassemia and HLA typing were performed on MDA products using NGS-based single-nucleotide polymorphism (SNP) haplotyping. Although two samples failed MDA, 94.3% (33/35) of samples were successfully amplified, achieving conclusive PGT results. Furthermore, 51.5% (17/33) of the embryos were diagnosed as unaffected non-carriers or carriers. Of the 17 unaffected embryos, nine (52.9%) were tested further  and identified as euploid via NGS-based aneuploid screening, in which five had HLA types matching affected children. One family did not achieve any unaffected euploid embryos. The two other families transferred HLA-matched and unaffected euploid embryos, resulting in two healthy 'savior babies.' NGS-PGT results were confirmed in prenatal diagnosis. Therefore, NGS-SNP was effective in performing PGT for multipurpose detection within a single PGT cycle.

Preimplantation genetic testing (PGT) for copy number variants of uncertain significance (CNV- VUS) in the genomic era: to do or not to do?

PURPOSE

To review cases of couples presented to our PGT-unit with copy number variants (CNVs) classified as variants of uncertain significance (VUS) in order to better understand their needs.

METHODS

Retrospective cohort study conducted in a tertiary medical-center, 2014-2019. We reviewed files of all couples applying for genetic counseling with CNVs classified as VUS. The main outcomes measured: number of VUS findings and their description, PGT-M procedures planned and performed, IVF cycles, clinical pregnancy, and live birth rates (LBR). VUS were classified according to the American-College of Medical-Genetics and Genomics classification at time of first consultation, and updated-December 2018.

RESULTS

Twenty-four couples presented with a total of 30 VUS. Twelve couples (50%) had isolated VUS and 12 (50%) had VUS diagnosed in addition to a pathogenic mutation. Initially, nine findings (30%) were defined as VUS; eight (27%) as likely benign (b-VUS); and 13 (43%) as likely pathogenic (p-VUS). PGT-M was recommended for 17/30 CNVs (56.6%), 12 (70%) of which, isolated VUS. No couple had other indications for IVF. To date, nine couples performed PGT-M for isolated VUS; LBR per-couple-55.5%. Five couples performed PGT-M for both pathogenic findings and VUS, LBR-80%. After reviewing VUS classifications, 30% remained unchanged, 20% were more severely defined, and 50% less severely defined.

CONCLUSION

The genomic era enables detection of VUS whose definition is subject to change as additional information becomes available. The uncertainty of variants' clinical significance and changes in VUS definition over time complicates genetic counseling. Revised guidelines for VUS interpretation and reevaluation of patient counseling before each pregnancy must be practiced when counseling them regarding the justification of PGT-M for their diagnosed VUS.

2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families

This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.

Review: Preimplantation genetic diagnosis (PGD) as a reproductive option in patients with neurodegenerative disorders

Preimplantation genetic diagnosis (PGD) was introduced in the late 1980s and represents an option for couples at risk of transmitting an inherited, debilitating or neurological disorder to their children. From a cleavage or blastocyst stage embryo, cell(s) are collected and then genetically analyzed for disease; enabling an unaffected embryo to be transferred into the uterus cavity. Nowadays, PGD has been carried out for several hundreds of heritable conditions including myotonic dystrophy, and for susceptibility genes involved in cancers of the nervous system. Currently, advanced molecular technologies with better resolution, such as array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing, are on the verge of becoming the gold standard in embryo preimplantation screening. Given this, it may be time for neurological societies to consider the published evidence to develop new guidelines for the integration of PGD into modern preventative neurology. Therefore, the main aim of this review is to illustrate the option of PGD to enable conception of an unaffected baby, and to assist clinicians and neurologists in the counseling of the patient at risk of transmitting an inherited disease, to explore the genetic journey throughout in vitro fertilization IVF with PGD.

Obstetric and Perinatal Outcomes in Pregnancies Conceived After Preimplantation Genetic Testing for Monogenetic Diseases

OBJECTIVE

To investigate whether the addition of embryo biopsy performed during preimplantation genetic testing for monogenic diseases is associated with a higher risk of obstetric and neonatal complications compared with in vitro fertilization (IVF) without preimplantation genetic testing or spontaneously conceived pregnancies.

METHODS

This is a cohort study of all pregnancies conceived after preimplantation genetic testing for monogenic diseases (PGT-M group) from 2006 to 2018 at Sheba Medical Center, Israel. The control groups included patients who had conceived spontaneously (spontaneous conception group) or by IVF without preimplantation genetic testing (IVF group) and delivered at Sheba Medical Center. The obstetrics outcomes were compared among the groups. Multivariable regression modeling was performed, focusing on the relationship between preimplantation genetic testing and adverse outcomes.

RESULTS

Final analysis included 345 singleton and 76 twin deliveries in the PGT-M group. The spontaneous conception group included 5,290 singleton and 92 twin deliveries. The IVF group included 422 singleton and 101 twin deliveries. Among singleton pregnancies, patients in the PGT-M group had a higher rate of hypertensive disorders (6.9%) compared with those in the spontaneous conception group (2.3%; odds ratio [OR] 3.3; 95% CI 1.9-4.8; adjusted odds ratio [aOR] 14.8; 95% CI 7.4-29.8) and the IVF group (4.7%; OR 1.5; 95% CI 0.8-2.7; aOR 5.9; 95% CI 1.9-18.2). Likewise, patients in the PGT-M group had a higher rate of small-for-gestational age neonates (12.4%) compared with those in the spontaneous conception group (3.9%; OR 3.4; 95% CI 2.4-4.9; aOR 2.3; 95% CI 1.5-3.4) and the IVF group (4.5%; OR 3; 95% CI 1.7-5.2; aOR 2.5; 95% CI 1.7-5.2). Among twin pregnancies, patients in the PGT-M group also had an increased rate of hypertensive disorders compared with those in the spontaneous conception group (4.3%; OR 4.1; 95% CI 1.2-13.3; aOR 10.9; 95% CI 2.3-50) and the IVF group (4%; OR 4.5; 95% CI 1.4-14.7; aOR 3.7; 95% CI 1.1-12.8).

CONCLUSION

Pregnancies conceived after preimplantation genetic testing for monogenic disorders were associated with an increased risk of obstetric complications compared with pregnancies conceived spontaneously or by IVF without preimplantation genetic testing.

[Pre-implantation genetic testing: Comparison between cleavage stage and blastocyst biopsy]

OBJECTIVES

Preimplantation genetic testing (PGT) refers to the set of techniques for testing whether embryos obtained through in vitro fertilization have genetic defect. There is a lack of global standardization regarding practices between countries or even from one center to another. In ours, biopsies are preferably performed on day 3 embryos, but also at the blastocyst stage on day 5. The blastocyst biopsy often requires systematic freezing of the embryos before obtaining the genetic results, whereas day 3 biopsy allows fresh embryo transfer of the healthy or balanced embryo after getting the genetic results. We wanted to compare the chances of success for couples performing PGT in our center according to the day of the biopsy.

METHODS

For this, we carried out a retrospective monocentric study including all PGT cycles performed between 2016 and 2019 divided into two groups: day 3 or day 5 biopsy.

RESULTS

There was no significant difference in terms of live birth rate (P=0.7375) after fresh embryo transfers, as well for pregnancy rates, clinical pregnancy rates, implantation rates and miscarriage rates. On the other hand, we observed higher live birth rates after frozen-thawed embryo transfer when the biopsy was performed on day 5 rather on day 3 (P=0.0001). We also wanted to assess what was the most efficient biopsy strategy in our laboratory. Our rates of useful embryos were similar regardless of the day of the biopsy (34% in D3 and 37.7% in D5, P=0.244). No statistical difference was found in the number of unnecessarily biopsied embryos in the two groups. But still, the percentage of embryos biopsied on D5 and immediately frozen was 42.8% (118 blastocysts), while no embryo biopsied on D3 led to this case.

CONCLUSION

Therefore, our results are in favor of generalization of the D5 biopsy as the international standard. However, the organizational, financial and logistical implications that this technic would impose make it unsystematic in our center.

Development and clinical application of a preimplantation genetic testing for monogenic disease (PGT-M) for beta thalassemia in Vietnam

Purpose

The purpose of this research is to study the clinical outcomes using a next-generation sequencing-based protocol allowing for simultaneous testing of mutations in the beta thalassemia (HBB) gene, including single nucleotide polymorphism (SNP) markers for PGT-M along with low-pass whole genome analysis of chromosome aneuploidies for PGT-A.

Methods

A combined PGT-M (thalassemia) plus PGT-A system was developed for patients undergoing IVF in Vietnam. Here we developed a system for testing numerous thalassemia mutations plus SNP-based testing for backup mutation analysis and contamination control using next-generation sequencing (NGS). Low -pass next-generation sequencing was used to assess aneuploidy in some of the clinical PGT cases. Patients underwent IVF followed by embryo biopsy at the blastocyst stage for combined PGT-A/M.

Results

Two cases have completed the entire process including transfer of embryos, while a further nine cases have completed the IVF and PGT-M/A analysis but have not completed embryo transfer. In the two cases with embryo transfer, both patients achieved pregnancy with an unaffected, euploid embryo confirmed through prenatal diagnosis. In the further nine cases, 39 embryos were biopsied and all passed QC for amplification. There were 8 unaffected embryos, 31 carrier embryos, and 11 affected embryos. A subset of 24 embryos also had PGT-A analysis with 22 euploid embryos and 2 aneuploid embryos.

Conclusions

Here we report the development and clinical application of a combined PGT-M for HBB and PGT-A for gross chromosome aneuploidies from 11 patients with detailed laboratory findings along with 2 cases that have completed embryo transfer.

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 INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Ante-natal counseling in phacomatoses

OBJECTIVES

Phacomatoses are a group of neuro-oculo-cutaneous syndromes/ neurocutaneous disorders, involving structures arising from the embryonic ectoderm. Most of phacomatoses including the most common ones:, neurofibromatosis type I and type II (NF1, NF2) and tuberosclerosis complex (TSC), are autosomal dominant genetic disorders with full penetrance and variable expression. As no effective treatment exists, the only way to prevent the disease, is by prenatal genetic diagnosis (either chorionic villus sampling-CVS or amniocentesis-AC) and termination of pregnancy or performing preimplantation genetic testing (PGT). As the risk for an affected offspring is 50% in every pregnancy of an affected parent, prenatal, and preimplantation testing are of great importance. However, those procedures are associated with technical and ethical concerns. This chapter shortly reviews the common phacomatoses emphasizes their genetics and inheritance. We will review the common methods for prenatal and preimplantation diagnoses and discuss its use in common phacomatoses.

CONCLUSION

Phacomatoses are common autosomal dominant genetic conditions with variable expression. Ante-natal genetic diagnosis is an appropriate approach for family planning in individuals affected by phacomatosis or parents of an affected child.

A multicenter, prospective, blinded, nonselection study evaluating the predictive value of an aneuploid diagnosis using a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy assay and impact of biopsy

OBJECTIVE

To determine the predictive value of an aneuploid diagnosis with a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy (PGT-A) assay in prognosticating the failure of a successful delivery.

DESIGN

Prospective, blinded, multicenter, nonselection study. All usable blastocysts were biopsied, and the single best morphologic blastocyst was transferred before genetic analysis. Preimplantation genetic testing for aneuploidy was performed after clinical outcome was determined. Clinical outcomes were compared to PGT-A results to calculate the predictive value of a PGT-A aneuploid diagnosis.

SETTING

Fertility centers.

PATIENT(S)

Couples undergoing their first in vitro fertilization cycle without recurrent pregnancy loss, antral follicle count < 8, or body mass index ≥ 35 kg/m².

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was the ability of the analytical result of aneuploid to predict failure to deliver (clinical result). A secondary outcome was the impact of the trophectoderm biopsy on sustained implantation.

RESULT(S)

Four hundred two patients underwent 484 single, frozen, blastocyst transfers. The PGT-A aneuploid diagnosis clinical error rate was 0%. There was no difference in sustained implantation between the study group and an age-matched control group, where biopsy was not performed (47.9% vs. 45.8).

CONCLUSION(S)

The PGT-A assay evaluated was highly prognostic of failure to deliver when an aneuploid result was obtained. Additionally, the trophectoderm biopsy had no detectable adverse impact on sustained implantation.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT02032264 and NCT03604107.

Haplotyping by linked-read sequencing (HLRS) of the genetic disease carriers for preimplantation genetic testing without a proband or relatives

BACKGROUND

In order to mitigate the risk of allele dropout (ADO) and ensure the accuracy of preimplantation genetic testing for monogenic disease (PGT-M), it is necessary to construct parental haplotypes. Typically, haplotype resolution is obtained by genotyping multiple polymorphic markers in both parents and a proband or a relative. Sometimes, single sperm typing, or tests on the polar bodies may also be useful. Nevertheless, this process is time-consuming. At present, there was no simple linkage analysis strategy for patients without affected relatives.

METHOD

To solve this problem, we established a haplotyping by linked-read sequencing (HLRS) method without the requirement for additional relatives. First, the haplotype of the genetic disease carriers in the family was constructed by linked-read sequencing, and then the informative single nucleotide polymorphisms (SNPs) in upstream and downstream mutation region were selected to construct the embryo haplotype and to determine whether the embryo was carrying the mutation. Two families were selected to validate this method; one with alpha thalassemia and the other with NDP gene disorder.

RESULTS

The haplotyping by linked-read sequencing (HLRS) method was successfully applied to construct parental haplotypes without recruiting additional family members; the method was also validated for PGT-M. The mutation carriers in these families were sequenced by linked-read sequencing, and their haplotypes were successfully phased. Adjacent SNPs of the mutation gene were identified. The informative SNPs were chosen for linkage analyses to identify the carrier embryos. For the alpha thalassemia family, a normal blastocyst was transferred to the uterus and the accuracy of PGT-M was confirmed by amniocentesis at 16 weeks of gestation.

CONCLUSIONS

Our results suggest that HLRS can be applied for PGT-M of monogenic disorders or de novo mutations where the mutations haplotype cannot be determined due to absence of affected relatives.

The decision-making process, experience, and perceptions of preimplantation genetic testing (PGT) users

PURPOSE

The decision to undergo preimplantation genetic testing (PGT) entails a variety of personal and societal variables. Although PGT technology is widely accepted and used, few studies have queried the motives and concerns of PGT users; moreover, in-depth qualitative data regarding the PGT experience is scant.

METHODS

In order to explore and analyze the experience, concerns, expectations, and attitudes toward the PGT technique and its implications, semi-structured interviews were conducted in a single tertiary medical center with 43 Israeli PGT users for HLA matching and autosomal dominant, autosomal recessive, and X-linked genetic disorders.

RESULTS

The primary considerations in choosing PGT were prevention of birth of a child who would suffer a terminal or chronic disease as well as abrogation of a familial genetic condition. Religion played a decisive role in accepting PGT as an antenatal option. Regarding satisfaction with the PGT experience, many interviewees highlighted the need for greater attention to be given to potential stages of failure throughout the procedure and the need for emotional support. Our clinical results regarding implantation rate and cumulative live birth rate are 38-40% and 27-30%, respectively.

CONCLUSION

This survey broadens understanding of the specialized needs of women, couples, and minority groups undergoing PGT and underscores the relevance of counseling services for PGT users.

Extended in vitro culture of human embryos demonstrates the complex nature of diagnosing chromosomal mosaicism from a single trophectoderm biopsy

STUDY QUESTION

What is the accuracy of preimplantation genetic testing for aneuploidies (PGT-A) when considering human peri-implantation outcomes in vitro?

STUDY ANSWER

The probability of accurately diagnosing an embryo as abnormal was 100%, while the proportion of euploid embryos classified as clinically suitable was 61.9%, yet if structural and mosaic abnormalities were not considered accuracy increased to 100%, with a 0% false positive and false negative rate.

WHAT IS ALREADY KNOWN

Embryo aneuploidy is associated with implantation failure and early pregnancy loss. However, a proportion of blastocysts are mosaic, containing chromosomally distinct cell populations. Diagnosing chromosomal mosaicism remains a significant challenge for PGT-A. Although mosaic embryos may lead to healthy live births, they are also associated with poorer clinical outcomes. Moreover, the direct effects of mosaicism on early pregnancy remain unknown. Recently, developed in vitro systems allow extended embryo culture for up to 14 days providing a unique opportunity for modelling chromosomal instability during human peri-implantation development.

STUDY DESIGN, SIZE, DURATION

A total of 80 embryos were cultured to either 8 (n = 7) or 12 days post-fertilisation (dpf; n = 73). Of these, 54 were PGT-A blastocysts, donated to research following an abnormal (n = 37) or mosaic (n = 17) diagnosis. The remaining 26 were supernumerary blastocysts, obtained from standard assisted reproductive technology (ART) cycles. These embryos underwent trophectoderm (TE) biopsy prior to extended culture.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We applied established culture protocols to generate embryo outgrowths. Outgrowth viability was assessed based on careful morphological evaluation. Nine outgrowths were further separated into two or more portions corresponding to inner cell mass (ICM) and TE-derived lineages. A total of 45 embryos were selected for next generation sequencing (NGS) at 8 or 12 dpf. We correlated TE biopsy profiles to both culture outcomes and the chromosomal status of the embryos during later development.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 73 embryos cultured to 12 dpf, 51% remained viable, while 49% detached between 8 and 12 dpf. Viable, Day 12 outgrowths were predominately generated from euploid blastocysts and those diagnosed with trisomies, duplications or mosaic aberrations. Conversely, monosomies, deletions and more complex chromosomal constitutions significantly impaired in vitro development to 12 dpf (10% vs. 77%, P < 0.0001). When compared to the original biopsy, we determined 100% concordance for uniform numerical aneuploidies, both in whole outgrowths and in the ICM and TE-derived outgrowth portions. However, uniform structural variants were not always confirmed later in development. Moreover, a high proportion of embryos originally diagnosed as mosaic remained viable at 12 dpf (58%). Of these, 71% were euploid, with normal profiles observed in both ICM and TE-derived lineages. Based on our validation data, we determine a 0% false negative and 18.5% false positive error rate when diagnosing mosaicism. Overall, our findings demonstrate a diagnostic accuracy of 80% in the context of PGT-A. Nevertheless, if structural and mosaic abnormalities are not considered, accuracy increases to 100%, with a 0% false positive and false negative rate.

LIMITATIONS REASONS FOR CAUTION

The inherent limitations of extended in vitro culture, particularly when modelling critical developmental milestones, warrant careful interpretation.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings echo current prenatal testing data and support the high clinical predictive value of PGT-A for diagnosing uniform numerical aneuploidies, as well as euploid chromosomal constitutions. However, distinguishing technical bias from biological variability will remain a challenge, inherently limiting the accuracy of a single TE biopsy for diagnosing mosaicism.

STUDY FUNDING, COMPETING INTEREST(S)

This research is funded by the Ghent University Special Research Fund (BOF01D08114) awarded to M.P., the Research Foundation-Flanders (FWO.KAN.0005.01) research grant awarded to B.H. and De Snoo-van't Hoogerhuijs Stichting awarded to S.M.C.d.S.L. We thank Ferring Pharmaceuticals (Aalst, Belgium) for their unrestricted educational grant. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Neonatal outcomes in singleton pregnancies conceived by fresh or frozen embryo transfer compared to spontaneous conceptions: a systematic review and meta-analysis

Purpose

The use of assisted reproductive technology (ART) has increased in the last 2 decades and continuous surveillance is needed. This systematic review aims to assess the risk of adverse neonatal outcomes (preterm birth [PTB], low birth weight [LBW], small-for-gestationalage [SGA] and large for gestational-age [LGA]), in singleton pregnancies conceived by fresh or frozen embryo transfer (FET) compared to spontaneous conceptions.

Methods

Cohort studies were identified from MEDLINE, Embase, Cochrane Library (January 2019), and manual search. Meta-analyses were performed to estimate odds ratios (OR) using random effects models in RevMan 5.3 and I-squared (I²) test > 50% was considered as high heterogeneity.

Results

After 3142 titles and abstracts were screened, 1180 full-text articles were assessed, and 14 were eligible. For fresh embryo transfer, the pooled ORs were PTB 1.64 (95% CI 1.46, 1.84); I² = 97%; LBW 1.67 (95% CI 1.52, 1.85); I² = 94%; SGA 1.46 [95% CI 1.11, 1.92]; I² = 99%, LGA 0.88 (95% CI 0.80, 0.87); I² = 80%). For frozen, the pooled ORs were PTB 1.39 (95% CI 1.34, 1.44); I² = 0%; LBW 1.38 (95% CI 0.91, 2.09); I² = 98%; SGA 0.83 (95% CI 0.57, 1.19); I² = 0%, LGA 1.57 (95% CI 1.48, 1.68); I² = 22%).

Conclusions

When compared with spontaneous pregnancies, fresh, but not frozen was associated with LBW and SGA. Both fresh and frozen were associated with PTB. Frozen was uniquely associated with LGA. Despite improvements in ART protocols in relation to pregnancy rates, attention is needed towards monitoring adverse neonatal outcomes in these pregnancies.

Electronic supplementary material

The online version of this article (10.1007/s00404-020-05593-4) contains supplementary material, which is available to authorized users.

Regulating Preimplantation Genetic Testing across the World: A Comparison of International Policy and Ethical Perspectives

Preimplantation genetic testing (PGT) is a reproductive technology that, in the course of in vitro fertilization (IVF), allows prospective parents to select their future offspring based on genetic characteristics. PGT could be seen as an exercise of reproductive liberty, thus potentially raising significant socioethical and legal controversy. In this review, we examine-from a comparative perspective-variations in policy approaches to the regulation of PGT. We draw on a sample of 19 countries (Australia, Austria, Belgium, Brazil, Canada, China, France, Germany, India, Israel, Italy, Japan, Mexico, Netherlands, Singapore, South Korea, Switzerland, United Kingdom, and the United States) to provide a global landscape of the spectrum of policy and legislative approaches (e.g., restrictive to permissive, public vs. private models). We also explore central socioethical and policy issues and contentious applications, including permissibility criteria (e.g., medical necessity), nonmedical sex selection, and reproductive tourism. Finally, we further outline genetic counseling requirements across policy approaches.

The role of prenatal diagnosis following preimplantation genetic testing for single-gene conditions: A historical overview of evolving technologies and clinical practice

Preimplantation genetic testing for monogenic conditions (PGT-M) has become a valued reproductive option for couples at risk of having a child with a single gene condition. In line with developments in molecular genetics, there has been an overall trend toward laboratory techniques with higher accuracy in comparison to earlier PGT-M techniques. The recommendation for confirmatory prenatal diagnostic testing has remained a standard component of PGT-M counseling, reflecting the inherent difficulties of testing the limited number of cells obtained from embryo biopsy, as well as recognition of the biological and human factors that may lead to misdiagnosis in a PGT-M cycle. Reported misdiagnosis rates are less than 1 in 200 pregnancies following PGT-M, although updated data regarding newer methods of PGT-M are required. There is limited evidence available regarding clinician and patient behavior in pregnancies resulting from PGT-M cycles. It remains essential that clinicians involved in the care of patients undergoing PGT-M provide appropriate counseling regarding the risks of misdiagnosis and the importance of confirmatory prenatal diagnosis. The nature of PGT-M test design lends itself to cell-free DNA-based noninvasive prenatal testing for monogenic conditions (NIPT-M), which is likely to become a popular method in the near future.

Does the prognosis after PGT for structural rearrangement differ between female and male translocation carriers?

RESEARCH QUESTION

Chromosomal translocations are known genetic causes of premature ovarian insufficiency syndrome. Are certain translocations associated with decreased capacity of small antral follicles to respond to exogenous FSH? Does the prognosis after preimplantation genetic testing for structural rearrangements differ in couples with female or male translocation carriers and according to the type of translocation?

DESIGN

A single-centre, retrospective, observational study covering a 10-year period. One hundred and thirty-nine females carrying a translocation were compared with 192 partners of male translocation carriers. To evaluate ovarian response to FSH, the follicular output rate was used, defined by ratio between the pre-ovulatory follicle count on day of HCG x 100/antral follicle count (AFC). To determine a cut-off of metaphase II oocytes and biopsied embryos as predictor of obtaining a balanced embryo transfer, receiver operator characteristic curves were plotted.

RESULT

A decreased capacity of small antral follicles to respond to exogenous FSH in female translocation carriers was found. The number of metaphase II oocytes in both groups was weakly informative as a predictor of obtaining an embryo transfer. The number of biopsied embryos had some clinical value, however, and allowed a cut-off of 6.5 to be determined for female translocation carriers versus 5.5 for the partners of male translocation carriers. Live birth rates, however, were not different between female and male translocations carriers.

CONCLUSIONS

Female translocation carriers may respond poorly to ovarian stimulation, and present a higher rate of unbalanced embryos, which means that higher gonadotrophin doses may be required to increase the number of biopsied embryos.

The First Asian, Single-Center Experience of Blastocyst Preimplantation Genetic Diagnosis with HLA Matching in Thailand for the Prevention of Thalassemia and Subsequent Curative Hematopoietic Stem Cell Transplantation of Twelve Affected Siblings

RESULTS

In 221 cycles from 138 patients (104 cycles requiring HLA matching), 90.5% had embryo(s) biopsied for genetic testing. There were 119 embryo transfers for thalassemia (76) and thalassemia-HLA cases (43), respectively, resulting in overall clinical pregnancy rates of 54.6%, implantation rates of 45.7%, and live birth rates of 44.1%. Our dataset included fifteen PGD-HLA live births with successful HSCT in twelve affected siblings, 67% using umbilical cord blood stem cells (UCBSC) as the only SC source.

CONCLUSIONS

We report favorable thalassemia PGD and PGD-HLA laboratory and clinical outcomes from a single center. The ultimate success in PGD-HLA is of course the cure of a thalassemia-affected sibling by HSCT. Our PGD-HLA HSCT series is the first and largest performed entirely in Asia with twelve successful and two pending cures and predominant UCBSC use.