Mapping ethical, legal, and social implications (ELSI) of preimplantation genetic testing (PGT)

PURPOSE

Preimplantation Genetic Testing (PGT) has attracted considerable ethical, legal, and social scrutiny, but academic debate often fails to reflect clinical realities.

METHODS

Addressing this disconnect, a review of 506 articles from 1999 to 2019 across humanities and social sciences was conducted to synthesize the Ethical, Legal, and Social Implications (ELSI) of PGT. This review mined PubMed, WoS, and Scopus databases, using both MeSH terms and keywords to map out the research terrain.

RESULTS

The findings reveal a tenfold increase in global research output on PGT's ELSI from 1999 to 2019, signifying rising interest and concern. Despite heightened theoretical discourse on selecting "optimal" offspring, such practices were scarcely reported in clinical environments. Conversely, critical issues like PGT funding and familial impacts remain underexplored. Notably, 86% of the ELSI literature originates from just 12 countries, pointing to a research concentration.

CONCLUSION

This review underscores an urgent need for ELSI research to align more closely with clinical practice, promoting collaborations among ethicists, clinicians, policymakers, and economists. Such efforts are essential for grounding debates in practical relevance, ultimately steering PGT towards ethical integrity, societal acceptance, and equitable access, aiming to harmonize PGT research with real-world clinical concerns, enhancing the relevance and impact of future ethical discussions.

Which One Is More Prominent in Recurrent Hydatidiform Mole, Ovum or Sperm?

Recurrent hydatidiform mole is defined as episodes of two molar pregnancies in a female. Often, complete moles only derive androgenic nuclear genome. We described two cases with repeated molar pregnancies attempted to prevent future episodes by performing intracytoplasmic sperm injection (ICSI) and preimplantation genetic diagnosis (PGD) to assess genetic disorders. The first patient had previously six complete molar pregnancies and advised to carry out ICSI with ovum donation to achieve a normal pregnancy. The second case had previously five molar pregnancies and no XY embryos from the ICSI/PGD process. We had to (at the insistence of the patient) transfer XX embryos in this patient which resulted in a complete hydatidiform mole (CHM). Hence, available data based on our patients and previous studies demonstrated that oocyte might play a critical role in the pathophysiology of recurrent hydatidiform mole, while it has not been often considered.

Outcomes of Preimplantation Genetic Diagnosis Cycles by Fluorescent In situ Hybridization of Infertile Males with Nonmosaic 47,XYY Syndrome

Background:

The 47,XYY syndrome could result in fertility problems. However, seldom studies reported comprehensive researches on the embryonic development and pregnancy outcomes of these patients. This study aimed to evaluate the clinical outcomes of nonmosaic 47,XYY patients performed with fluorescent in situ hybridization (FISH) and preimplantation genetic diagnosis (PGD) treatment.

Methods:

This was a retrospective study. Between January 2012 and May 2017, 51 infertile males with nonmosaic 47,XYY syndrome underwent FISH-PGD were included in the study. According to sex chromosomal FISH results, embryos were classified as normal signal, no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups, respectively. The incidence of each group, the fixation rate, and hybridization rate were calculated. Embryonic development and pregnancy outcomes were also analyzed. The measurement data were analyzed with Student's t-test. The comparison of categorical data was analyzed with the Chi-square test and Fisher's exact test when expected cell count was <5.

Results:

The 53 PGD cycles with 433 embryos were analyzed. The fixation rate was 89.6%, while the hybridization rate was 96.4%. There were 283 embryos with two sex chromosomal signals with clear diagnosis (65.4%). The numbers of no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups were 45 (10.4%), 14 (3.2%), 24 (5.5%), and 67 (15.5%), respectively. Embryos with abnormal signals were abandoned. The number of good-quality embryos was 210 (57.4%), including implanted embryos on day 4/day 5 and cryopreserved. The rates of good-quality embryos in the no nuclei fixed (22.2%), no signal in fixed nuclei (28.6%), and suspensive signal groups (33.3%) were comparable (P > 0.05), and were significantly lower than the normal signal group (66.4%, P < 0.001). The clinical pregnancy rates of fresh and frozen embryos transferred cycles were 70.6% and 85.7%, respectively.

Conclusions:

Among embryos with a clear diagnosis of sex chromosome, about one-fifth showed abnormal signals. Embryos with two sex chromosomal signals are more likely to develop into good-quality ones. The application of the PGD by FISH may help to improve the clinical outcomes.

Ethics in prion disease

This paper is intended to discuss some of the scientific and ethical issues that are created by increased research efforts towards earlier diagnosis, as well as to treatment of, human prion diseases (and related dementias), including the resulting consequences for individuals, their families, and society. Most patients with prion disease currently are diagnosed when they are about 2/3 of the way through their disease course (Geschwind et al., 2010a; Paterson et al., 2012b), when the disease has progressed so far that even treatments that stop the disease process would probably have little benefit. Although there are currently no treatments available for prion diseases, we and others have realized that we must diagnose patients earlier and with greater accuracy so that future treatments have hope of success. As approximately 15% of prion diseases have a autosomal dominant genetic etiology, this further adds to the complexity of ethical issues, particularly regarding when to conduct genetic testing, release of genetic results, and when or if to implement experimental therapies. Human prion diseases are both infectious and transmissible; great care is required to balance the needs of the family and individual with both public health needs and strained hospital budgets. It is essential to proactively examine and address the ethical issues involved, as well as to define and in turn provide best standards of care.

An update of preimplantation genetic diagnosis in gene diseases, chromosomal translocation, and aneuploidy screening

Preimplantation genetic diagnosis (PGD) is gradually widely used in prevention of gene diseases and chromosomal abnormalities. Much improvement has been achieved in biopsy technique and molecular diagnosis. Blastocyst biopsy can increase diagnostic accuracy and reduce allele dropout. It is cost-effective and currently plays an important role. Whole genome amplification permits subsequent individual detection of multiple gene loci and screening all 23 pairs of chromosomes. For PGD of chromosomal translocation, fluorescence in-situ hybridization (FISH) is traditionally used, but with technical difficulty. Array comparative genomic hybridization (CGH) can detect translocation and 23 pairs of chromosomes that may replace FISH. Single nucleotide polymorphisms array with haplotyping can further distinguish between normal chromosomes and balanced translocation. PGD may shorten time to conceive and reduce miscarriage for patients with chromosomal translocation. PGD has a potential value for mitochondrial diseases. Preimplantation genetic haplotyping has been applied for unknown mutation sites of single gene disease. Preimplantation genetic screening (PGS) using limited FISH probes in the cleavage-stage embryo did not increase live birth rates for patients with advanced maternal age, unexplained recurrent abortions, and repeated implantation failure. Polar body and blastocyst biopsy may circumvent the problem of mosaicism. PGS using blastocyst biopsy and array CGH is encouraging and merit further studies. Cryopreservation of biopsied blastocysts instead of fresh transfer permits sufficient time for transportation and genetic analysis. Cryopreservation of embryos may avoid ovarian hyperstimulation syndrome and possible suboptimal endometrium.

Does blastomere biopsy in preimplantation genetic diagnosis affect early serum β-hCG levels?

Objective

To determine whether the serum β-human chorionic gonadotropin (hCG) profile following preimplantation genetic diagnosis (PGD) is lower than that of intracytoplasmic sperm injection (ICSI) cycles.

Methods

A total of 129 PGD cycles and 1,161 age-matched ICSI cycles, which resulted in pregnancy (serum β-hCG≥5 mIU/mL) on post-ovulation day (POD) 12 were included. We compared the mean serum β-hCG levels on POD 12, 14, 21, and 28, doubling time of serum hCG, and created a cut-off value for predicting a singleton pregnancy in each group.

Results

The mean serum β-hCG concentration of the PGD group was significantly lower than that of the control group on POD 12, 14, and 21. The doubling time of serum β-hCG at each time interval showed no significant difference. The cut-off-value of serum β-hCG for predicting a single viable pregnancy was 32.5 mIU/mL on POD 12 and 113.5 mIU/mL on POD 14 for the PGD group, which was lower than that for the control group.

Conclusion

Blastomere biopsy may decrease the β-hCG-producing activity of the trophoblasts, especially in early pregnancy. Setting a lower cut-off value of serum β-hCG for predicting pregnancy outcomes in PGD may be needed.