Transferring embryos with genetic anomalies detected in preimplantation testing: an Ethics Committee Opinion

Klinefelter syndrome: etiology and clinical considerations in male infertility†

Klinefelter syndrome (KS) is the most prevalent chromosomal disorder occurring in males. It is defined by an additional X chromosome, 47,XXY, resulting from errors in chromosomal segregation during parental gametogenesis. A major phenotype is impaired reproductive function, in the form of low testosterone and infertility. This review comprehensively examines the genetic and physiological factors contributing to infertility in KS, in addition to emergent assisted reproductive technologies, and the unique ethical challenges KS patients face when seeking infertility treatment. The pathology underlying KS is increased susceptibility for meiotic errors during spermatogenesis, resulting in aneuploid or even polyploid gametes. Specific genetic elements potentiating this susceptibility include polymorphisms in checkpoint genes regulating chromosomal synapsis and segregation. Physiologically, the additional sex chromosome also alters testicular endocrinology and metabolism by dysregulating interstitial and Sertoli cell function, collectively impairing normal sperm development. Additionally, epigenetic modifications like aberrant DNA methylation are being increasingly implicated in these disruptions. We also discuss assisted reproductive approaches leveraged in infertility management for KS patients. Application of assisted reproductive approaches, along with deep comprehension of the meiotic and endocrine disturbances precipitated by supernumerary X chromosomes, shows promise in enabling biological parenthood for KS individuals. This will require continued multidisciplinary collaboration between experts with background of genetics, physiology, ethics, and clinical reproductive medicine.

Transfer of embryos with positive PGT-M results: Genetic Counselors' perspectives and ethical considerations

Increasing numbers of fertility patients use preimplantation genetic testing for monogenic conditions (PGT-M) during in vitro fertilization (IVF). While PGT-M is primarily used to avoid implanting embryos with a monogenic condition, patients can request to transfer an embryo with the monogenic condition (positive embryo transfer), especially in cases where an IVF cycle results in no unaffected embryos. Transferring embryos with known disease-causing variants raises ethical concerns. There is limited understanding about how stakeholders in the assisted reproductive technology (ART) field approach these issues. In this study, genetic counselors were sent a survey to gather insight into their views about transferring embryos with different monogenic conditions. N = 99 genetic counselors completed the survey, 22 of whom had experience with patients requesting or deciding to transfer an embryo with a monogenic condition (positive embryo transfer experience). Most participants, including those with positive embryo transfer experience, were supportive of positive embryo transfer, regardless of the genetic condition. While participating genetic counselors were largely supportive of all patient decisions, they reported increased moral uneasiness around transferring embryos with life-limiting monogenic conditions, such as Huntington's disease. Further investigation into the experiences of genetic counselors who have experienced positive embryo transfer requests in practice can help delineate the ethical questions that ART providers face in this context and clarify how genetic counselors can contribute to establishing guidelines in the ART field.

Patient interest in and clinician reservations on polygenic embryo screening: a qualitative study of stakeholder perspectives

PURPOSE

We explored and compared perspectives of reproductive endocrinology and infertility specialists (REIs) and in vitro fertilization (IVF) patients regarding polygenic embryo screening (PES), a new type of preimplantation screening that estimates the genetic chances of developing polygenic conditions and traits in the future.

METHODS

Qualitative thematic analysis of semi-structured interviews with US-based REIs and IVF patients.

RESULTS

Clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more frequently than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer PES to patients or were willing to do so only under certain circumstances, while many patients expressed interest in PES. Both stakeholder groups envisioned multiple potential benefits or uses of PES and raised multiple potential, interrelated concerns about PES.

CONCLUSION

A gap exists between clinician and patient attitudes toward PES; clinicians generally maintained reservations about such screening and patients indicated interest in it. Clinicians and patients sometimes imagined using PES to prepare for the birth of a predisposed or "affected" individual-a rationale that is often associated with prenatal testing. Many clinicians and patients held different attitudes depending on what is specifically screened, despite the sometimes blurry distinction between conditions and traits. Considerations raised by clinicians and patients may help guide professional societies in developing guidelines to navigate the uncertain terrain of PES.

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.

PGT-M, a Useful Tool to Manage the Lynch Syndrome Transmission

Lynch syndrome is one of the most common hereditary cancer sensitivity syndromes and is caused by autosomal-dominant germline mutations in DNA mismatch repair genes. In patients affected by this syndrome, pre-implantation genetic testing for monogenic disorders (PGT-M) could be the elective technique used to prevent the transmission of this hereditary syndrome to offspring. Notably, despite the severity of the condition, some authors have observed a markedly lower demand for PGT-M in these patients compared to those with other hereditary conditions. A 34-year-old woman with a medical history of Lynch syndrome associated with endometrial cancer came to the Villa Mafalda fertility center in Rome in order to conceive a healthy baby. In a pre-implantation genetic testing for aneuploidy (PGT-A) + PGT-M cycle, eight blastocysts were formed. Six out of eight blastocysts were affected by the same mother syndrome. One of the other two was aneuploid and the other one was a mosaic embryo, which resulted in a healthy pregnancy. The aim of this report is to emphasize the importance of a multidisciplinary approach to managing patients with this condition. In vitro fertilization (IVF), specifically PGT-M, is a tool that allow patients to conceive biological children with lower risk of inheriting the disease.

Preimplantation genetic testing for monogenic disorders: clinical experience with BRCA1 and BRCA2 from 2010-2021

PURPOSE

Our aim was to describe the reproductive decisions and outcomes of BRCA-positive patients who used preimplantation genetic testing for monogenic disorders (PGT-M).

METHODS

We performed a retrospective case series of all PGT-M cycles for BRCA variants between 2010-2021 at a large urban academic fertility center. All patients who underwent ≥ 1 cycle of IVF with PGT-M for BRCA1 or BRCA2 were included. The primary outcome was total number of BRCA-negative euploid embryos per patient.

RESULTS

Sixty four patients underwent PGT-M for BRCA variants. Forty-five percent (29/64) were BRCA1-positive females, 27% (17/64) were BRCA2-positive females, 16% (10/64) were BRCA1-positive males, 11% (7/64) were BRCA2-positive males, and one was a BRCA1 and BRCA2-positive male. There were 125 retrieval cycles with PGT-M, and all cycles included PGT for aneuploidy (PGT-A). Eighty-six percent (55/64) of patients obtained at least one BRCA- negative euploid embryo, with median of 1 (range 0-10) BRCA-negative euploid embryo resulted per cycle and median 3 (range 0-10) BRCA-negative euploid embryos accumulated per patient after a median of 2 (range 1-7) oocyte retrievals. Sixty-four percent (41/64) of patients attempted at least one frozen embryo transfer (FET) with a total of 68 FET cycles. Fifty-nine percent (40/68) of embryos transferred resulted in live births. Subgroup analysis revealed different reproductive pathways for BRCA1-positive females, BRCA2-positive females, and BRCA1/2-positive males (p < 0.05).

CONCLUSION

PGT-M is a viable option for BRCA-positive patients to avoid transmission while building their families. Most patients in our cohort achieved pregnancy with BRCA-negative euploid embryos.

Clinical management of mosaic results from preimplantation genetic testing for aneuploidy of blastocysts: a committee opinion

This revised document incorporates a growing number of published studies about mosaic embryo transfer and provides current evidence-based considerations for the clinical management of embryos with mosaic results on preimplantation genetic testing for aneuploidy. This document replaces the document titled "Clinical management of mosaic results from preimplantation genetic testing for aneuploidy (PGT-A) of blastocysts: a committee opinion," published in 2020 (Fertil Steril 2020;114:246-54).

Divergence Between Clinician and Patient Perspectives on Polygenic Embryo Screening: A Qualitative Study

Objective

To explore and compare the perspectives of clinicians and patients on polygenic embryo screening.

Design

Qualitative.

Subjects

Fifty-three participants: 27 reproductive endocrinology and infertility specialists and 26 patients currently undergoing in vitro fertilization or had done so within the last five years.

Main Outcome Measures

Qualitative thematic analysis of interview transcripts.

Results

Both clinicians and patients often held favorable views of screening embryos for physical or psychiatric conditions, though clinicians tended to temper their positive attitudes with specific caveats. Clinicians also expressed negative views about screening embryos for traits more often than patients, who generally held more positive views. Most clinicians were either unwilling to discuss or offer polygenic embryo screening to patients or were willing to do so only under certain circumstances, while many patients expressed interest in polygenic embryo screening. Both sets of stakeholders envisioned multiple potential benefits or uses of polygenic embryo screening; the most common included selection and/or prioritization of embryos, receipt of more information about embryos, and preparation for the birth of a predisposed or "affected" child. Both sets of stakeholders also raised multiple potential, interrelated concerns about polygenic embryo screening. The most common concerns among both sets of stakeholders included the potential for different types of "biases" - most often in relation to selection of embryos with preferred genetic chances of traits -, the probabilistic nature of polygenic embryo screening that can complicate patient counseling and/or lead to excessive cycles of in vitro fertilization, and a lack of data from long-term prospective studies supporting the clinical use of polygenic embryo screening.

Conclusion

Despite patients' interest in polygenic embryo screening, clinicians feel such screening is premature for clinical application. Though now embryos can be screened for their genetic chances of developing polygenic conditions and traits, many clinicians and patients maintain different attitudes depending on what is specifically screened, despite the blurry distinction between conditions and traits. Considerations raised by these stakeholders may help guide professional societies as they consider developing guidelines to navigate the uncertain terrain of polygenic embryo screening, which is already commercially available.

Indications and management of preimplantation genetic testing for monogenic conditions: a committee opinion

This statement is offered to update and expand on the prior American Society for Reproductive Medicine preimplantation genetic testing (PGT) opinion, elucidate the current clinical and technical complexities specific to PGT for monogenic conditions, assist providers in supporting patient understanding of and access to this technology, and offer considerations for the development of future clinical and laboratory guidelines on PGT for monogenic conditions.

Informed consent in assisted reproduction: an Ethics Committee opinion

Informed consent is a process in which the patient is supported in developing an understanding of medical options (including risks, benefits, and alternatives) and coming to a voluntary and autonomous decision.

On the reproductive capabilities of aneuploid human preimplantation embryos

In IVF cycles, the application of aneuploidy testing at the blastocyst stage is quickly growing, and the latest reports estimate almost half of cycles in the US undergo preimplantation genetic testing for aneuploidies (PGT-A). Following PGT-A cycles, understanding the predictive value of an aneuploidy result is paramount for making informed decisions about the embryo's fate and utilization. Compelling evidence from non-selection trials strongly supports that embryos diagnosed with a uniform whole-chromosome aneuploidy very rarely result in the live birth of a healthy baby, while their transfer exposes women to significant risks of miscarriage and chromosomally abnormal pregnancy. On the other hand, embryos displaying low range mosaicism for whole chromosomes have shown reproductive capabilities somewhat equivalent to uniformly euploid embryos, and they have comparable clinical outcomes and gestational risks. Therefore, given their clearly distinct biological origin and clinical consequences, careful differentiation between uniform and mosaic aneuploidy is critical in both the clinical setting when counseling individuals and in the research setting when presenting aneuploidy studies in human embryology. Here, we focus on the evidence gathered so far on PGT-A diagnostic predictive values and reproductive outcomes observed across the broad spectrum of whole-chromosome aneuploidies detected at the blastocyst stage to obtain evidence-based conclusions on the clinical management of aneuploid embryos in the quickly growing PGT-A clinical setting.

A review of normative documents on preimplantation genetic testing: Recommendations for PGT-P

PURPOSE

Recently, preimplantation genetic testing (PGT) for polygenic conditions (PGT-P) has been introduced commercially. In view of the lack of specific guidance on this development, we analyzed normative documents on PGT for monogenic conditions (PGT-M) to understand what we can learn from these documents for recommendations for PGT-P.

METHODS

We conducted a systematic review of normative guidelines and recommendations on PGT-M. The aim was to understand what the current consensus and disagreements are on ethical acceptability of PGT-M and how this compares with PGT-P.

RESULTS

We analyzed 38 documents by advisory committees at the national, European, and global level. In total, 2 themes were identified, which included the following: (1) what PGT is considered appropriate for and (2) who can make decisions regarding the use of PGT. Many aspects of PGT-M documents apply to PGT-P as well. Additional factors such as the fact that PGT-P screens for risk indications of multiple polygenic conditions increase ethical difficulties regarding severity, risk, autonomy, and informed decision-making.

CONCLUSION

On the basis of PGT-M normative documents, we conclude that ethical acceptability for PGT-P is limited. Our findings present various factors that have to be considered for the development of guidelines and the appropriateness of PGT.

From Genotype to Phenotype: Polygenic Prediction of Complex Human Traits

Decoding the genome confers the capability to predict characteristics of the organism (phenotype) from DNA (genotype). We describe the present status and future prospects of genomic prediction of complex traits in humans. Some highly heritable complex phenotypes such as height and other quantitative traits can already be predicted with reasonable accuracy from DNA alone. For many diseases, including important common conditions such as coronary artery disease, breast cancer, type I and II diabetes, individuals with outlier polygenic scores (e.g., top few percent) have been shown to have 5 or even 10 times higher risk than average. Several psychiatric conditions such as schizophrenia and autism also fall into this category. We discuss related topics such as the genetic architecture of complex traits, sibling validation of polygenic scores, and applications to adult health, in vitro fertilization (embryo selection), and genetic engineering.

Fetal Screening for Chromosomal Abnormalities

With more and more reproductive-aged women opting to pursue genetic screening during pregnancy, health care professionals must understand the variety of testing options available as well as the advantages and limitations of each testing option. Presently, no single screening test is universally believed to be superior because the combination of the specific test and the population being tested determines the range of potential identifiable conditions as well as the positive predictive values. As a result, pre- and posttest counseling are not always straightforward and may require discussions with multiple specialists including genetic counselors, obstetricians, and pediatricians/neonatologists. The purpose of this review is to summarize the screening options currently available to pregnant women to determine their risk of having a child affected by a chromosomal disorder. Screening for chromosomal abnormalities using ultrasonography, maternal serum analytes, cell-free DNA, and preimplantation genetic testing will be discussed here. Advances in the field, including the possible future use of cell-based noninvasive prenatal screening (NIPS) as a more accurate method for genetic screening and the incorporation of screening for copy number variants (microdeletions and duplications) into traditional cell-free NIPS will also be reviewed.

Ethical considerations of preconception and prenatal gene modification in the embryo and fetus

The National Academies of Sciences and Medicine 2020 consensus statement advocates the reinstatement of research in preconception heritable human genome editing (HHGE), despite the ethical concerns that have been voiced about interventions in the germline, and outlines criteria for its eventual clinical application to address monogenic disorders. However, the statement does not give adequate consideration to alternative technologies. Importantly, it omits comparison to fetal gene therapy (FGT), which involves gene modification applied prenatally to the developing fetus and which is better researched and less ethically contentious. While both technologies are applicable to the same monogenic diseases causing significant prenatal or early childhood morbidity, the benefits and risks of HHGE are distinct from FGT though there are important overlaps. FGT has the current advantage of a wealth of robust preclinical data, while HHGE is nascent technology and its feasibility for specific diseases still requires scientific proof. The ethical concerns surrounding each are unique and deserving of further discussion, as there are compelling arguments supporting research and eventual clinical translation of both technologies. In this Opinion, we consider HHGE and FGT through technical and ethical lenses, applying common ethical principles to provide a sense of their feasibility and acceptability. Currently, FGT is in a more advanced position for clinical translation and may be less ethically contentious than HHGE, so it deserves to be considered as an alternative therapy in further discussions on HHGE implementation.

Legal challenges in reproductive genetics

Recent advancements in reproductive genetics have resulted in the availability of an extraordinary amount of new and detailed information for patients and providers. Whereas this information can inform many who are facing difficult clinical decisions, it can also introduce complex and uncertain choices. Expanded carrier screening and preimplantation genetic diagnosis for aneuploidy are important examples of new genetic techniques that are now widely used in reproductive medicine. This paper will explore these techniques through a medical-legal prism to better understand the opportunities and obligations incumbent on both patients and providers in this new age of genetic diagnosis.

Physician autonomy or discrimination: the risks and limits of saying "no"

Respect for patient autonomy is a critical concept in the training of all physicians. Most physicians will make clinical recommendations on a daily basis that reflect a marriage of evidence-based medical fact and the deeply felt aspirations and boundaries that patients share with them. While most physicians are well versed and comfortable managing issues of patient autonomy, many are less confident about ethical and legal guidelines for expressing their own autonomy in clinical decision-making. This paper will review the legal landscape surrounding the patient-physician relationship with a focus on when and how physicians can exercise their personal and professional autonomy in their clinical practice.

Ethical and moral perspectives of individuals who considered/used preimplantation (embryo) genetic testing

This study examined perspectives on the ethical implications of preimplantation genetic testing (PGT) among individuals who actually (not hypothetically) used or considered using PGT. Most of the prior patient-centered research on PGT ethics used qualitative designs (9 out of the 11 articles) and focused only on single gene testing. This cross-sectional study used an anonymous online questionnaire; 15 items assessed potential ethical concerns involved in PGT decision-making, including clinical indications for PGT, the greater implications of PGT for society, and unused embryo disposition. N = 207 individuals (mean female/male age 35.7/38.9 years, 21% Hispanic or non-White) who had recently used or considered using PGT for single gene (60%) or for chromosomal testing (40%) completed the questionnaire. Most respondents supported PGT screening for disease conditions with childhood or adult onset that are untreatable (64%-85% across items); most opposed PGT for trait selection (76%-81%). Most respondents agreed that PGT aids in parental decision-making (66%-67%), although some expressed concern over potential unforeseen consequences (25%-30%). Regarding disposition of embryos without known genetic abnormalities, most respondents favored freezing indefinitely (86%) or donating to another family (69%), while for embryos with genetic abnormalities, most respondents favored donating to research (78%) or destroying them (62%). Stratification by religious affiliation revealed several differences, such as less acceptance of PGT for diseases that occur in adulthood and have no treatment options among Protestants (p = .015) and greater willingness to donate surplus embryos to research among participants without a religious affiliation (p < .001). These results are limited by the relatively homogeneous sample of participants (mostly White, married, and predominantly college-educated). In summary, participants who considered/used PGT found PGT acceptable overall for screening for disease conditions; most opposed using PGT for trait selection. Our novel questionnaire provides a structured tool for assessing the ethical perspectives surrounding the use of PGT.

Aneuploid embryo transfer: clinical policies and provider opinions at United States fertility clinics

OBJECTIVE

To describe institutional clinical policies and individual provider opinions regarding aneuploid embryo transfer (aET).

DESIGN

A survey about clinical policies was electronically sent to Society for Assisted Reproductive Technology (SART) member laboratory directors, and a separate survey about personal opinions was electronically sent to all SART members.

SETTING

Not applicable.

PATIENTS

Patients pursuing preimplantation genetic testing for aneuploidy (PGT-A).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Current clinical policies about aET were described. Individual provider opinions about aET in the context of specific aneuploidies and mosaicism were also described.

RESULTS

A total of 48 laboratory directors and 212 individual providers responded to their respective surveys. Twelve (25%) clinics report that they do not have a policy regarding aET, but clinics performing PGT-A in >100 cycles per year were more likely to have a policy. Half of the individual providers agree that an embryo with trisomy 21 should be available for aET, but most disagreed with aET of embryos with other aneuploidies and most were either unsure about or unwilling to transfer embryos with mosaicism. Those who worked in primarily patient-facing roles held more agreeable opinions regarding aET.

CONCLUSION

There is no consensus regarding ideal clinical policies for aET. The wide range of current clinical practices and individual provider opinions regarding under what circumstances, if any, aET should be available to patients indicates that this is a divisive issue among ART providers, and there is a clear need for specific professional guidelines to address this issue.

Clinical management of mosaic results from preimplantation genetic testing for aneuploidy (PGT-A) of blastocysts: a committee opinion

Since the advent of preimplantation genetic testing for aneuploidy (PGT-A) in the 1990s, substantial changes in test methodology and technology now allow the detection and reporting of intermediate chromosome copy number (commonly referred to as mosaicism) for aneuploidy in a trophectoderm biopsy sample. Clinicians are grappling with how to interpret such findings and how to counsel patients about embryo transfer decision-making. This document reviews the available literature and outlines the various issues surrounding the reporting of intermediate copy number and consideration of storage or transfer of blastocysts with intermediate copy number results. This document does not endorse, nor does it suggest that PGT-A is appropriate for all cases of in vitro fertilization.

Screening for Fetal Chromosomal Abnormalities: ACOG Practice Bulletin, Number 226

Prenatal testing for chromosomal abnormalities is designed to provide an accurate assessment of a patient's risk of carrying a fetus with a chromosomal disorder. A wide variety of prenatal screening and diagnostic tests are available; each offers varying levels of information and performance, and each has relative advantages and limitations. When considering screening test characteristics, no one test is superior in all circumstances, which results in the need for nuanced, patient-centered counseling from the obstetric care professional and complex decision making by the patient. Each patient should be counseled in each pregnancy about options for testing for fetal chromosomal abnormalities. It is important that obstetric care professionals be prepared to discuss not only the risk of fetal chromosomal abnormalities but also the relative benefits and limitations of the available screening and diagnostic tests. Testing for chromosomal abnormalities should be an informed patient choice based on provision of adequate and accurate information, the patient's clinical context, accessible health care resources, values, interests, and goals. All patients should be offered both screening and diagnostic tests, and all patients have the right to accept or decline testing after counseling.The purpose of this Practice Bulletin is to provide current information regarding the available screening test options available for fetal chromosomal abnormalities and to review their benefits, performance characteristics, and limitations. For information regarding prenatal diagnostic testing for genetic disorders, refer to Practice Bulletin No. 162, Prenatal Diagnostic Testing for Genetic Disorders. For additional information regarding counseling about genetic testing and communicating test results, refer to Committee Opinion No. 693, Counseling About Genetic Testing and Communication of Genetic Test Results. For information regarding carrier screening for genetic conditions, refer to Committee Opinion No. 690, Carrier Screening in the Age of Genomic Medicine and Committee Opinion No. 691, Carrier Screening for Genetic Conditions. This Practice Bulletin has been revised to further clarify methods of screening for fetal chromosomal abnormalities, including expanded information regarding the use of cell-free DNA in all patients regardless of maternal age or baseline risk, and to add guidance related to patient counseling.

The Ethics of Genetic Cognitive Enhancement: Gene Editing or Embryo Selection?

Recent research with human embryos, in different parts of the world, has sparked a new debate on the ethics of genetic human enhancement. This debate, however, has mainly focused on gene-editing technologies, especially CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). Less attention has been given to the prospect of pursuing genetic human enhancement by means of IVF (In Vitro Fertilisation) in conjunction with in vitro gametogenesis, genome-wide association studies, and embryo selection. This article examines the different ethical implications of the quest for cognitive enhancement by means of gene-editing on the one hand, and embryo selection on the other. The article focuses on the ethics of cognitive enhancement by means of embryo selection, as this technology is more likely to become commercially available before cognitive enhancement by means of gene-editing. This article argues that the philosophical debate on the ethics of enhancement should take into consideration public attitudes to research on human genomics and human enhancement technologies. The article discusses, then, some of the recent findings of the SIENNA Project, which in 2019 conducted a survey on public attitudes to human genomics and human enhancement technologies in 11 countries (France, Germany, Greece, the Netherlands, Poland, Spain, Sweden, Brazil, South Africa, South Korea, and United States).

Healthy live births from transfer of low-mosaicism embryos after preimplantation genetic testing for aneuploidy

PURPOSE

This study evaluated the potential viability of embryos with low mosaicism level (< 50%) by comparing the clinical outcomes of single mosaic versus euploid blastocyst transfer. In addition, the live birth outcomes for various types of mosaicism with respect to abnormalities in chromosome structure and content were analyzed.

METHODS

This study included patients who underwent in vitro fertilization with preimplantation genetic testing for aneuploidy (PGT-A). The PGT-A cycles performed through next-generation sequencing with single euploid or mosaic embryo transfers were included. We collected 299 frozen single embryo transfer cycles-216 single euploid and 83 mosaic-between July 2016 and July 2018. This study analyzed clinical outcomes, including fetal karyotyping by using amniocentesis, gestational age at delivery, and live birth weight after single mosaic embryo transfer.

RESULTS

The average birth weight of infants in the euploid and mosaic blastocyst transfer groups was 3146.2 and 2997.7 g, respectively. The karyotyping results of prenatal diagnosis in all pregnant women were normal. Our study indicated that mosaic embryos can develop into euploid healthy infants with various levels or types of mosaicism. No significant difference was observed between infants from euploid and mosaic blastocyst transfers.

CONCLUSION

If patients have no euploid embryos, mosaic embryos can be transferred as they have potential for implantation and development into euploid healthy infants. This study is invaluable for counseling clinical results after single mosaic embryo transfers.

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.

Is it ever morally permissible to select for deafness in one's child?

As reproductive genetic technologies advance, families have more options to choose what sort of child they want to have. Using preimplantation genetic diagnosis (PGD), for example, allows parents to evaluate several existing embryos before selecting which to implant via in vitro fertilization (IVF). One of the traits PGD can identify is genetic deafness, and hearing embryos are now preferentially selected around the globe using this method. Importantly, some Deaf families desire a deaf child, and PGD-IVF is also an option for them. Selection for genetic deafness, however, encounters widespread disapproval in the hearing community, including mainstream philosophy and bioethics. In this paper I apply Elizabeth Barnes' value-neutral model of disability as mere-difference to the case of selecting for deafness. I draw on evidence from Deaf Studies and Disability Studies to build an understanding of deafness, the Deaf community, and the circumstances relevant to reproductive choices that may obtain for some Deaf families. Selection for deafness, with deafness understood as mere-difference and valued for its cultural identity, need not necessitate impermissible moral harms. I thus advocate that it is sometimes morally permissible to select for deafness in one's child.

Compassionate transfer: patient requests for embryo transfer for nonreproductive purposes

A patient request to transfer embryos into her body in a location or at a time when pregnancy is highly unlikely to occur is deemed a request for "compassionate transfer" and often reflects the patient's deeply personal, strongly held preferences and values. It is ethically permissive for physicians to honor or decline such requests if they do so in a nondiscriminatory manner.

Utility and First Clinical Application of Screening Embryos for Polygenic Disease Risk Reduction

For over 2 decades preimplantation genetic testing (PGT) has been in clinical use to reduce the risk of miscarriage and genetic disease in patients with advanced maternal age and risk of transmitting disease. Recently developed methods of genome-wide genotyping and machine learning algorithms now offer the ability to genotype embryos for polygenic disease risk with accuracy equivalent to adults. In addition, contemporary studies on adults indicate the ability to predict polygenic disorders with risk equivalent to monogenic disorders. Existing biobanks provide opportunities to model the clinical utility of polygenic disease risk reduction among sibling adults. Here, we provide a mathematical model for the use of embryo screening to reduce the risk of type 1 diabetes. Results indicate a 45-72% reduced risk with blinded genetic selection of one sibling. The first clinical case of polygenic risk scoring in human preimplantation embryos from patients with a family history of complex disease is reported. In addition to these data, several common and accepted practices place PGT for polygenic disease risk in the applicable context of contemporary reproductive medicine. In addition, prediction of risk for PCOS, endometriosis, and aneuploidy are of particular interest and relevance to patients with infertility and represent an important focus of future research on polygenic risk scoring in embryos.

Transfer of embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M): experience of two high-volume fertility clinics

PURPOSE

To assess the experiences of two large fertility clinics in which embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M) were transferred upon patient request, in order to explore the nature of the conditions for which these requests have been made and review ethical considerations.

METHODS

Retrospective review of previous embryo transfers at the NYU Langone Fertility Center and ORM Fertility was performed. Embryo transfers prior to May 2019 in which embryo biopsy and PGT-M occurred were reviewed, and transferred embryos that were positive for a monogenic disorder (excluding autosomal recessive carriers) were identified.

RESULTS

Seventeen patients were identified who elected to transfer 23 embryos that tested positive for nine different monogenic disorders. Most of the embryos transferred were positive for disorders that are autosomal dominant (15/23), are adult-onset (14/23), are associated with reduced penetrance (16/23), and have available management to lessen symptom severity (22/23). Transfer of positive embryos most commonly occurred for hereditary cancer susceptibility syndromes (9/23 embryos), particularly hereditary breast and ovarian cancer syndrome.

CONCLUSIONS

When unaffected embryos are not produced following in vitro fertilization with PGT-M, some patients request to transfer embryos with positive test results. The majority of transfers were for embryos positive for adult-onset, reduced penetrance diseases. As these requests will likely increase over time, it is essential to consider the practical and ethical implications.

The clinical application of gene editing: ethical and social issues

Gene-editing techniques have progressed rapidly in the past 5 years. There are already ongoing human somatic gene-editing clinical trials for multiple diseases. And there has been one purported scenario of human germline gene editing in late 2018. In this paper, we will review the current state of the technology, discuss the ethical and social issues that surround the various forms of gene editing, as well as review emerging stakeholder data from professionals, the ‘general public’ and individuals and families dealing with genetic diseases potentially treatable by gene editing.

Transfer of embryos with segmental mosaicism is associated with a significant reduction in live-birth rate

OBJECTIVE

To evaluate the impact of segmental mosaicism on pregnancy outcomes from the transfer of embryos previously designated as euploid.

DESIGN

Retrospective cohort analysis.

SETTING

Single, private, high-volume fertility center.

PATIENT(S)

Three hundred and twenty-seven women who underwent 377 frozen single euploid embryo transfers.

INTERVENTION(S)

Trophectoderm biopsy of embryos cultured to the blastocyst stage, where all transferred embryos were designated euploid by high-density oligonucleotide array comparative genomic hybridization (aCGH); after ascertaining all outcomes, revaluation of aCGH results for evidence of segmental mosaicism (defined as mosaicism on a portion of a chromosome).

MAIN OUTCOME MEASURE(S)

Live-birth rate and spontaneous abortion rate.

RESULT(S)

Of the 377 embryos transferred, 357 were euploid with no mosaicism, and 20 embryos had segmental mosaicism. Segmental mosaics had a statistically significantly lower live-birth rate compared with euploid controls (30.0% vs. 53.8%). When controlling for age and day of Trophectoderm biopsy, the odds for live birth after transfer of segmental mosaics were reduced by 66% compared with euploid controls (0.34; 95% confidence interval, 0.13-0.92). The spontaneous abortion rate was statistically significantly higher after transfer of segmental mosaics compared with euploid controls (40.0% vs. 18.2%).

CONCLUSION(S)

Blastocysts with segmental mosaicism have reduced reproductive potential but retain the ability to result in live birth. These results support reporting segmental mosaicism to optimize selection of a single embryo for transfer that will maximize the chance of life birth.

Review of patient decision-making factors and attitudes regarding preimplantation genetic diagnosis

The increasing technical complexity and evolving options for repro-genetic testing have direct implications for information processing and decision making, yet the research among patients considering preimplantation genetic diagnosis (PGD) is narrowly focused. This review synthesizes the literature regarding patient PGD decision-making factors, and illuminates gaps for future research and clinical translation. Twenty-five articles met the inclusion criteria for evaluating experiences and attitudes of patients directly involved in PGD as an intervention or considering using PGD. Thirteen reports were focused exclusively on a specific disease or condition. Five themes emerged: (1) patients motivated by prospects of a healthy, genetic-variant-free child, (2) PGD requires a commitment of time, money, energy and emotions, (3) patients concerned about logistics and ethics of discarding embryos, (4) some patients feel sense of responsibility to use available technologies, and (5) PGD decisions are complex for individuals and couples. Patient research on PGD decision-making processes has very infrequently used validated instruments, and the data collected through both quantitative and qualitative designs have been inconsistent. Future research for improving clinical counseling is needed to fill many gaps remaining in the literature regarding this decision-making process, and suggestions are offered.