Merits of embryo screening debated.
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Bone Marrow Transplantation↗
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Results for “Sex Preselection”
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The decision to cancel a preimplantation genetic diagnosis cycle.
It has been suggested that a minimum number (six) of cumulus-oocyte complexes (COCs) should be retrieved for fertilization to offer enough chances to ensure a pregnancy after a preimplantation genetic diagnosis (PGD) procedure. Therefore a decision to cancel a PGD cycle should be adequately weighted to offer the patients the highest chances to obtain a pregnancy. We describe a case where, after retrieving only three COCs suitable for fertilization, a triplet pregnancy was obtained. This case suggests that, although low numbers of COCs can reduce the effectiveness of the PGD procedure, other factors are involved in its final result. Thus, the opportunity of routinely cancelling such cycles should be reconsidered. In addition, this is, to our knowledge, the first case where sex selection was carried out to prevent the birth of carriers of the abnormal gene, and not of affected offspring.
Adult↗
The legal implications of refusing to provide prenatal diagnosis in low-risk pregnancies or solely for sex selection.
As more people learn about prenatal diagnosis, medical personnel are increasingly being asked to perform these procedures in both low-risk pregnancies and for purposes of sex selection. Analysis of present legal rules illustrates that it is highly unlikely genetic counselors will be subjected to legal liability for refusing to provide prenatal diagnosis in these situations. This freedom from liability will probably continue into the foreseeable future, despite recent developments in the areas of informed consent and allocation of scarce medical resources that tend to limit the traditionally broad deference given to medical personnel.
Ethics, Medical↗
Ethics and medical genetics in the United States: a national survey.
The approaches of 295 medical geneticists in the United States to 14 clinical problems and 3 screening situations that required a moral choice are summarized. These data are part of a survey of 682 geneticists in 19 nations. Of 490 U.S. geneticists asked to participate, 295 (60%) returned anonymous detailed questionnaires. There was strong (greater than 75%) consensus that preserving the mother's confidentiality overrides disclosure of true paternity; that conflicting test results, new/controversial interpretations of results, and ambiguous/artifactual results should be disclosed; that artificial insemination by donor, adoption, taking chances, contraception, sterilization, and in-vitro fertilization with a donor egg should be presented as reproductive options to carriers of disorders not diagnosable prenatally; that prenatal diagnosis should be performed for patients who refuse abortion and for maternal anxiety in the absence of medical indications; that screening in the workplace should be voluntary. There was no consensus about disclosure of a diagnosis of Huntington disease or hemophilia A to relatives at risk, against the patient's wishes, or about disclosure of parental translocations. Geneticists in the U.S. differed from 18 other nations in presenting surrogate motherhood as an option (67%); willingness to perform prenatal diagnosis for sex selection or refer (62%); and disclosure of XY genotype in a female (62%). Men were more likely than women to say that they would give directive counseling. Women were more likely than men to say that they would perform prenatal diagnosis for maternal anxiety or for sex selection.
Confidentiality↗
Pre-conceptional sex selection.
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Acid-Base Equilibrium↗
Preconceptional selection of fetal sex.
Background information is given on postconceptional and preconceptional methods of selecting fetal sex. Among the preconceptional methods presented are treatment of the sperm to isolate either the X or the Y chromosome, timing of insemination and the effect of ionic concentrations in the woman's body as controlled by the dietary intake of minerals. The authors studied 281 couples, 21 of whom were later excluded, who adhered to a diet specific in its amounts of calcium, magnesium, sodium and potassium. This dietary method of preconceptional selection of fetal sex resulted in the anticipated outcome in about 80% of the cases.
Calcium, Dietary↗
A study of sex predetermination in the mealy bug Planococcus citri (Risso).
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Animals↗
Attitudes towards sex selection in the Western world.
It appears that in most Western countries, son preference is somewhat stronger than daughter preference. However, when one considers the preference of women it looks as though the opposite pattern is emerging. There is a considerable social acceptance of 'light' methods of sex selection (such as diets), even though these methods are not proven to be effective. The inclination to use sperm separation methods appears to be greater in the United States than in some European countries. There are indications that a preference for boys or for girls is associated with attitudes towards technology, child-rearing style and the stereotyping of boys or girls.
Attitude↗
Attitudes towards sex selection for non-medical reasons: a review.
Early non-invasive fetal sexing is widely available over the Internet, leading to concerns about its possible use for sex selection. The aim of this review is to summarise the results of surveys describing lay attitudes towards sex selection for non-medical reasons to help address or inform such concerns. A search of electronic databases and key journals was supplemented by an Internet search and citation-tracking. Twenty-one quantitative studies were identified. Most were conducted in the US, with five recent studies in the UK and Germany. Most studies found that, overall, people were not in favour of sex selection. However, this varied from 94 to 18%. People may hold more negative attitudes when the method of sex selection is specified, particularly if this involves termination of pregnancy (TOP). Attitudes towards the general availability of sex selection are less negative than those towards personal use. Attitudes were consistently negative in German surveys. Little is known of such attitudes outside the US, the UK and Germany, and how such attitudes may change as new sex selection technologies become available. Studies of use of early non-invasive fetal sexing for sex selection for non-medical reasons are needed to assess the extent to which concerns about usage are justified and to assist in debates on how these might be most appropriately addressed.
Attitude↗
Understanding the opposition.
Current debates about sex selection start from a paradox: on the one hand, the 'liberal' argument in favour of sex selection is often thought to be sound; but on the other hand there is widespread public opposition to sex selection. So it is worth spending some time examining the arguments against sex selection. Four different types of argument are identified: (i) religious arguments; (ii) consequentialist arguments, mainly concerning disturbance to the sex ratio; (iii) arguments to the effect that sex selection involves a failure to respect the autonomy of a child; (iv) arguments to the effect that the motivation for sex selection brings with it an instrumental attitude to children not compatible with a child's need for unconditional acceptance and love. In the end the conclusion is reached that none of these arguments provide decisive arguments against the liberal thesis that sex selection ought to be permitted, especially where 'family balancing' is envisaged. In the light of this conclusion the issue of fetal sexing followed by selective feticide as a method of sex selection is discussed. It is argued that sex selection is not in general a good reason for abortion, but that this practice may become unstoppable.
Attitude↗
Regulating post-implantation fetal sex selection: a UK perspective.
This article reviews the current and potential laws relevant to post-implantation fetal social sex selection and considers whether they could provide an effective deterrent and control of the practice, if the United Kingdom decided that such control were desirable. It concludes that enacting, drafting and enforcing of any legislation throws up many difficult practical and ethical issues. These issues need to be debated and further information collected before any legislation is rushed into.
Abortion, Legal↗
The obstetrician's view: ethical and societal implications of non-invasive prenatal diagnosis.
We believe non-invasive prenatal diagnosis is about to have a massive impact on the way fetal medicine is practised. There will be many great advantages and improvements, but the technology also has the potential to be used for non-medical reasons such as sex selection and paternity testing. We discuss some of the issues that may face obstetricians in the future as a result of this emerging technology.
DNA↗
Attitudes to and practices regarding sex selection in China.
This paper explores the problem of China's 'missing' girls--estimated to run into many millions. It considers the impact of the underpinning Confucian value system in China that has produced a culture of son preference and which, together with China's compulsory family planning program and 'one child policy', has effectively established a 'one son policy'. Discussion of the various means by which the birth or survival of daughters have traditionally been prevented provides the context for identifying the contribution of new sex selection procedures to the maintenance of son preference in contemporary Chinese society. The paper concludes that China's son preference is not simply a personal problem for the millions of 'missing girls' who were destined to live a shorter life and for the surviving girls who continue to face considerable discrimination simply because they are of the 'wrong' sex; it heralds a social and demographic disaster of major proportions for which neither the government nor the people of China appear to have the will or the means to forestall.
China↗
Noninvasive detection of fetal sex: the laboratory diagnostician's view.
Toward the end of the twentieth century it was discovered that cell-free fetal DNA sequences could be detected in maternal blood plasma. Initially, Y-chromosome sequences originating from male fetuses were targeted in cell-free DNA extracted from maternal plasma in order to demonstrate proof of this concept towards the development of noninvasive prenatal diagnosis methods. Clinical application of this approach is now possible. Fetal sex can be detected through a procedure that is noninvasive with respect to the fetus. Specifically, the presence of Y-chromosome sequences in maternal blood plasma indicates that the fetus is male, whereas lack of a signal will indicate that the fetus is female. Fetal sex can be detected very early, from at least the 7th week of pregnancy (and even earlier, according to several studies), about two months before this information is available through ultrasound scanning. Although the controversial issue of fetal sexing is not new, it is expected that with the availability of an accurate noninvasive test, public interest will rise. It is therefore imperative that an authorized committee of experts in each country generates an official policy regarding application of the test.
Attitude↗
'Reproductive autonomy' versus public good?
Hitherto sex selection could be achieved only by destroying any fetus or child of the unwanted sex. Sperm selection may change that. The technology could be used to 'balance' families. However its use in certain developing countries might 'unbalance' populations, with serious, if unintended, consequences.
Humans↗
Issues and concerns of couples presenting for preimplantation genetic diagnosis (PGD).
BACKGROUND: The use of preimplantation genetic diagnosis (PGD) to select genetically 'normal' human embryos and to transfer them to the uterus of a woman has generated considerable controversy. Debate has occurred over the implications of PGD, sex selection, safety of embryonic manipulation and eugenics. This study evaluates a range of social and moral concerns of couples towards PGD and assisted reproductive technologies (ART) prior to treatment to obtain unbiased authentic attitudes independent of the treatment cycle and the outcome. METHODS: A total of 121 subjects were administered a structured questionnaire after each couple's in vitro fertilization (IVF) or genetic counselling session. Group A consisted of 41 subjects presenting for PGD of single gene disorders (PGD-SG) and group B consisted of 48 subjects undertaking PGD for aneuploidy screening (PGD-AS). A control group consisted of 32 subjects that were about to commence their first IVF cycle. RESULTS AND DISCUSSION: All groups found PGD to be a highly acceptable treatment. They expressed little concern about its extension to testing non-disease states such as sex and they were strongly in favour of a shared decision-making model in which couples have considerable autonomy over decisions about the embryo(s) to transfer. Differences between the groups included issues surrounding the transfer of embryos, restrictions to PGD and the destruction of embryos.
Adult↗
Personal desires of patients and social obligations of geneticists: applying preimplantation genetic diagnosis for non-medical sex selection.
The arguments against the use of preimplantation genetic diagnosis (PGD) for non-medical sex selection are analysed. It is concluded that the distinction between medical and non-medical reasons is difficult to maintain, that the disproportionality of means and end is not a decisive counterargument and that the fear of damage to the reputation of PGD does not justify the refusal of controversial applications. Moreover, since non-medical sex selection does not belong to basic health care, it should not be equally accessible to all. The position defended in this article is founded on two basic principles: (1). medical reasons have priority on non-medical reasons, and (2). personal reasons do not qualify for public funding. In order to respect both principles, it is proposed that restrictions should be installed to control the number of requests for social sexing and that a tax should be imposed on these elective services. The tax should compensate the society for the investment it made in the training and education of the physician.
Adult↗
The influence of polyvinylpyrrolidone on freezing of bovine IVF blastocysts following biopsy.
A study was conducted to develop a better freezing protocol for in vitro developed biopsied bovine blastocysts. Biopsied blastocysts were exposed to 1.8 M ethylene glycol (EG) + 0.05 M trehalose (T) and different concentration (5, 10, and 20%) of polyvinylpyrrolidone (PVP). Exposure to the solutions alone did not affect their in vitro development (Experiment 1). Experiments 2, 3, and 4 tested the viability of biopsied blastocysts cryopreserved in 1.8 M EG + different concentrations of T (0, 0.05, 0.1, and 0.3 M), 1.8 M EG + different concentrations of PVP (0, 5, 10, and 20%), and 1.8 M EG + 0.05 M T + different concentrations of PVP (0, 5, 10, and 20%), respectively. The proportion of biopsied blastocysts that reexpanded following cryopreservation in 1.8 M EG + 0.05 M T (38.5%) and 1.8 M EG + 0.1 M T (36.1%) was significantly (P < 0.05) higher than the proportion that reexpanded in 1.8 M EG + 0.3 M T (13.9%) (Experiment 2). The viability and the percentage of embryos that developed to > 250 microns in diameter in the 5, 10, and 20% PVP groups (77.8 and 50.0%, 78.1 and 43.8%, 76.9 and 65.4%, respectively) were significantly higher than those that developed cryopreserved without PVP (55.1 and 20.7%) (Experiment 3). Optimum development of in vitro culture of frozen-thawed biopsied blastocysts was obtained using 1.8 M EG + 0.05 M T and 20% PVP. Analysis of blastocysts > 250 microns in diameter showed that the number of ICM cells of biopsied blastocysts cryopreserved in 1.8 M EG + 0.05 M T with or without PVP was not different from the number of unfrozen biopsied blastocysts. These results indicate that PVP has some beneficial effect on freezing of biopsied bovine blastocysts.
Animals↗