Selection Of Preimplantation Embryos Research Articles

Noninvasive amino acid turnover predicts human embryo aneuploidy

Assisted reproduction technology has two significant problems: low success rates and multiple pregnancies. Because of these problems, the priority in IVF clinics is to develop a potential diagnostic test that can be used to select the embryos with the ultimate developmental competence. Aneuploidy screening as embryo selection criteria will ensure that the transferred embryos are euploid and high implantation rate. We hypothesize that aneuploidy in human preimplantation embryos could be discriminated by their amino acid metabolism profile in the spent culture media. Preimplantation genetic testing for aneuploidy results and spent embryo culture medium amino acid content were analyzed for 58 couples. The next-generation sequencing technique was used and coupled with TE biopsy. Forty euploid and 71 aneuploid blastocysts were evaluated. Embryos were cultured individually until day 5 or 6 of embryo development. Spent culture medium was collected after finishing the culture. There was no statistical difference between D3 and D5 embryo morphology between euploid and aneuploid embryos (p > .05). Eight amino acids, including SER, GLY, HIS, ARG, THR, ALA, PRO, and TYR, were detected in the culture medium from the blank control group, euploid group, and aneuploid group. Only TYR amino acid concentration was found significantly higher in the aneuploid group compared to the euploid group (p < .003). Tyrosine amino acid levels equal to and above 76.38 µmol/L could be considered aneuploid. Aneuploid embryos demonstrate altered amino acid turnover in vitro relative to euploid counterparts. A noninvasive method of amino acid profiling will be of value as a tool for routine preimplantation embryo selection among all patient groups.

Selection of preimplantation embryos using time-lapse microscopy in in vitro fertilization: State of the technology and future directions.

In this review, our aim is to give an overview of the state of the technology and clinical outcomes of time-lapse microscopy in improving embryo selection as a key step in in vitro fertilization (IVF). Using traditional incubators, morphologic assessment of the fertilized embryos is limited to snapshots at a few discrete points in time, reducing the amount of information that could potentially be obtained. Time-lapse monitoring overcomes this limitation without exposing the embryos to environmental changes. Moreover, time-lapse may introduce new dynamic markers of embryo competence as well as a versatile embryo evaluation and provides novel information regarding human embryo development. In the last few years, various algorithms have been developed correlating the kinetics of early embryo development to blastocyst formation, implantation potential, chromosomal content and live birth rate. There is not yet a universally accepted algorithm, and significant knowledge gaps remain that can provide opportunities for further research in this field.

In our Own Image: Eugenics and the Genetic Modification of People

Science needs to be defended. With the Enlightenment we saw the beginnings of the widespread use of reason to manipulate nature for the benefit of mankind. As reason gave us more freedom from the darker side of nature it also questioned the authority of the ruling elites, eventually resulting in political emancipation. The position of science and reason has changed in contemporary discourse. There is now a wide feeling that interference with nature has led to many problems. Environmentalism is one expression of this; and another is the suspicion of genetic technology, with calls for more state regulation and restriction. In our Own Image stands in defence of science by arguing for individual freedom. In the subtitle of his book David Galton, who is Professor of Human Metabolism and Genetics at St Bartholomew's Hospital, declares the history of genetic science so that these issues can be dealt with in a reasoned way. ‘Eugenics’ is derived from the Greek for ‘good birth’, and Galton makes clear that manoeuvres such as preimplantation embryo selection and gene enhancement are eugenic. He also shows how the idea as well as the word goes back at least as far as Ancient Greece. Citing Plato's Republic and Plutarch's historical account of the city state of Sparta he gives a fascinating account of how eugenics was originally perceived by the ruling classes as a tool to improve the population. We then move to more recent history and the birth of modern evolutionary theory with Charles Darwin. The Origin of Species was received into a society that understood itself through the concept of race, with its justification of the class structure at home and the imperialist project abroad. The book describes how Francis Galton (cousin of Darwin and no relation to the author) used Darwin's ideas of natural selection to develop a theory of eugenics that received broad support until it was discredited by the Nazis. Galton offers disturbing examples of how eugenic ideas have since been twisted by coercive state machinery. Clearly the worst atrocities occurred under the Nazis, under whose auspices ‘euthanasia’ clinics sat on children's wards to eradicate the ‘pathological phenotype’, with the ‘Final Solution’ marking the ultimate perversion of eugenics. However, 10 000 ‘socially inadequate’ people had been sterilized in California by 1935 and compulsory sterilization of people with ‘inferior qualities’ was still occurring in Sweden until 1976, by which time some 60 000 young women had been sterilized. Eugenic Acts were narrowly defeated in Parliament here in 1913 and 1934. Galton carefully considers public concerns about the new gene and reproductive technologies. For example, does the technology defy nature? As well as pointing out that pacemakers and corneal implants are likewise unnatural he shows how attitudes towards previous breakthroughs in reproductive science have softened from initial revulsion to acceptance. (He cites letters to the BMJ in 1945 suggesting that the newly introduced artificial insemination was wrong because it ‘encourages masturbation’ and ‘would assuredly cause a break-up of Western civilisation’.) He goes on to suggest that if parents are prepared to go to enormous expense to improve their child's environment through private education why should they not be free to enhance the child's genetic inheritance. Parallels are drawn between such freedoms and freedom for abortion. He also discusses at length the concerns surrounding how the technology could be used by insurance companies, employers and the state to discriminate against the individual. He seems to suggest that the best way to negotiate these difficulties is to support the rights of the individual. The question becomes not whether to allow the use of the new technologies (inevitable in a society organized around the market) but how we view the relation between the individual and society. The author cites JS Mill in On Liberty where he suggests that ‘the only purpose for which power can be rightfully exercised over any member of a civilised community against his will is to prevent harm to others’—indeed, Galton's worries about cloning derive from potential risks to the child. However, if we believe we have a right to genetic privacy it will then be inconsistent to deny an individual the right to use safe technology in starting a family. Galton marshals convincing arguments for scientific and individual freedom in gene and reproductive technology. In my opinion society is too quick to assume that our genes define who we are. It is this erroneous notion that underlies suspicion of the technology.

In our Own Image: Eugenics and the Genetic Modification of People

Science needs to be defended. With the Enlightenment we saw the beginnings of the widespread use of reason to manipulate nature for the benefit of mankind. As reason gave us more freedom from the darker side of nature it also questioned the authority of the ruling elites, eventually resulting in political emancipation. The position of science and reason has changed in contemporary discourse. There is now a wide feeling that interference with nature has led to many problems. Environmentalism is one expression of this; and another is the suspicion of genetic technology, with calls for more state regulation and restriction. In our Own Image stands in defence of science by arguing for individual freedom. In the subtitle of his book David Galton, who is Professor of Human Metabolism and Genetics at St Bartholomew's Hospital, declares the history of genetic science so that these issues can be dealt with in a reasoned way. ‘Eugenics’ is derived from the Greek for ‘good birth’, and Galton makes clear that manoeuvres such as preimplantation embryo selection and gene enhancement are eugenic. He also shows how the idea as well as the word goes back at least as far as Ancient Greece. Citing Plato's Republic and Plutarch's historical account of the city state of Sparta he gives a fascinating account of how eugenics was originally perceived by the ruling classes as a tool to improve the population. We then move to more recent history and the birth of modern evolutionary theory with Charles Darwin. The Origin of Species was received into a society that understood itself through the concept of race, with its justification of the class structure at home and the imperialist project abroad. The book describes how Francis Galton (cousin of Darwin and no relation to the author) used Darwin's ideas of natural selection to develop a theory of eugenics that received broad support until it was discredited by the Nazis. Galton offers disturbing examples of how eugenic ideas have since been twisted by coercive state machinery. Clearly the worst atrocities occurred under the Nazis, under whose auspices ‘euthanasia’ clinics sat on children's wards to eradicate the ‘pathological phenotype’, with the ‘Final Solution’ marking the ultimate perversion of eugenics. However, 10 000 ‘socially inadequate’ people had been sterilized in California by 1935 and compulsory sterilization of people with ‘inferior qualities’ was still occurring in Sweden until 1976, by which time some 60 000 young women had been sterilized. Eugenic Acts were narrowly defeated in Parliament here in 1913 and 1934. Galton carefully considers public concerns about the new gene and reproductive technologies. For example, does the technology defy nature? As well as pointing out that pacemakers and corneal implants are likewise unnatural he shows how attitudes towards previous breakthroughs in reproductive science have softened from initial revulsion to acceptance. (He cites letters to the BMJ in 1945 suggesting that the newly introduced artificial insemination was wrong because it ‘encourages masturbation’ and ‘would assuredly cause a break-up of Western civilisation’.) He goes on to suggest that if parents are prepared to go to enormous expense to improve their child's environment through private education why should they not be free to enhance the child's genetic inheritance. Parallels are drawn between such freedoms and freedom for abortion. He also discusses at length the concerns surrounding how the technology could be used by insurance companies, employers and the state to discriminate against the individual. He seems to suggest that the best way to negotiate these difficulties is to support the rights of the individual. The question becomes not whether to allow the use of the new technologies (inevitable in a society organized around the market) but how we view the relation between the individual and society. The author cites JS Mill in On Liberty where he suggests that ‘the only purpose for which power can be rightfully exercised over any member of a civilised community against his will is to prevent harm to others’—indeed, Galton's worries about cloning derive from potential risks to the child. However, if we believe we have a right to genetic privacy it will then be inconsistent to deny an individual the right to use safe technology in starting a family. Galton marshals convincing arguments for scientific and individual freedom in gene and reproductive technology. In my opinion society is too quick to assume that our genes define who we are. It is this erroneous notion that underlies suspicion of the technology.