Blurring boundaries. Interviews with PGT couples about comprehensive chromosome screening

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.

A mathematical model for predicting the number of transferable blastocysts in next-generation sequencing-based preimplantation genetic testing

PURPOSE

To investigate the clinical factors that could be used predict the number of transferable blastocysts in preimplantation genetic testing (PGT) cycles based on next-generation sequencing (NGS) and formed form a mathematical model to predict the chance likelihood of obtaining one transferable blastocyst, which is helpful for genetic counseling.

METHODS

This retrospective study enrolled couples undergoing PGT cycles for chromosomal structural rearrangement (PGT-SR, n = 363, 202 with reciprocal translocation carriers, 131 with Robertsonian translocation carriers, 30 with inversion carriers), monogenic diseases (PGT-M, n = 47), and for Aneuploidies (PGT-A, n = 132) from January 2015 to October 2018. Stepwise multiple linear regression analysis was used to identify the factors relevant for obtaining at least one transferable blastocyst. The factors that predict the number of biopsied blastocysts were further analyzed.

RESULTS

The transferable blastocyst rates were 29.94, 41.99, 49.09, 41.42, and 44.37% in the reciprocal translocation carrier, Robertsonian translocation carrier, inversion carrier, PGT-M, and PGT-A cycles, respectively. The number of transferable blastocysts in these cycles were 0.3004 × the number of biopsied blastocysts (NBB) - 0.0031, 0.4063 × NBB + 0.0460, 0.5762 × NBB - 0.3128, 0.3611 × NBB + 0.1910, and 0.4831 × NBB - 0.0970, respectively. Furthermore, the number of MII oocytes and female age were clinical predictors of NBB in reciprocal translocation and PGT-A couples, while the number of MII oocytes was the only clinical predictor in Robertsonian translocation carriers, inversion carriers, and PGT-M couples.

CONCLUSIONS

The number of biopsied blastocysts was the only clinical predictor of the ability to obtain a transferable blastocyst in PGT cycles; therefore, for clinical practice, theoretically the minimum numbers of biopsied blastocysts is 4 in reciprocal translocation carrier and 3 in couples undergoing PGT for other reasons. The number of MII oocytes and female age were clinical predictors of the number of biopsied blastocysts. With the mathematical models in our study as a reference, in clinical practice, clinicians will be able to conduct a more targeted genetic consultation for different kinds of PGT patients.

Motives and considerations regarding PGT in couples carrying a structural chromosomal abnormality: a qualitative exploration

Purpose

This study aims to describe the motives and considerations of couples carrying a structural chromosomal abnormality deciding on preimplantation genetic testing (PGT).

Methods

A qualitative exploratory study was conducted using semi-structured dyadic interviews with 13 couples (N = 26) carrying a structural chromosomal abnormality. All couples had an informative consultation in our PGT centre in the Netherlands.

Results

Almost all couples considered PGT or natural conception combined with prenatal diagnosis (PND) as the only two reproductive options. Among several considerations mentioned, the majority indicated that the wish to increase the chance of a successful pregnancy was the most important motive to opt for PGT. All couples who opted for PGT had first tried to conceive spontaneously and entered the PGT programme because of their adverse experiences during these attempts (infertility, recurrent miscarriage, termination of pregnancy, birth of an affected child). Couples that refrained from PGT were of advanced maternal age and expressed the long trajectory of PGT as the main reason to refrain. If conceiving spontaneously would not lead to an ongoing pregnancy, these couples also indicated that they would use PGT.

Conclusion

This study shows that couples carrying a structural chromosomal abnormality consider PGT and spontaneous conception with PND as relevant reproductive options. They are looking for the option that is in their opinion the fastest way to establish a successful pregnancy. Information on the perceived pros and cons of PGT or spontaneous conception in these couples can help to optimize counselling and psychological support during the decision-making process.