Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sex Preselection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed1992

Genetic counselor attitudes towards fetal sex identification and selective abortion.

Thirty-four prenatal genetic counselors (all but one non-M.D.s) in seven American cities were interviewed on attitudes which might plausibly affect counselor-client interchanges. They overwhelmingly endorse both non-directive counseling and the pro-choice ethos which supports a woman's absolute right to abortion in the early stages of pregnancy. However, they also overwhelmingly condemn using prenatal diagnosis for sex selection purposes. Therefore, counselors experience continual stress from clients who evoke the conflict inherent between these two stances. Counselors use a variety of coping mechanisms to minimize this cognitive dissonance. Avoidance through out-referral or invoking institutional policies forbidding prenatal diagnosis for sex selection purposes is a diminishing option and not possible with clients who have or offer a medical indication. More common is the use of psychological coping mechanisms. By elevating the ideals of non-directiveness and female autonomy counselors better tolerate client values in conflict with their own. Some redefine the category of 'unwanted pregnancy' to include fetuses of the 'wrong sex'; others redefine the problem as their own ethnocentricism. Empowering counselors to set the protocols they use to screen applicants for prenatal diagnosis would not remove these conflicts. Many counselors believe a ban on releasing fetal sex information while abortion is still a legal option would be organizationally or legally unacceptable, or a violation of patient automony. A complicating factor is that 60% of the counselors interviewed would prefer to know fetal sex in their own pregnancies. Counselors reflect the ambivalence of American society in balancing conflicting social goals.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Legal↗
PubMed1993

Prenatal diagnosis and sex selection in 19 nations.

As part of a study of ethics and human genetics in 19 nations, we surveyed attitudes of 71 medical geneticists in 4 developing nations (Brazil, Greece, India and Turkey), and 611 geneticists in 15 developed nations, using anonymous questionnaires. Overall, 52% in India, 30% in Brazil, 29% in Greece, and 20% in Turkey would perform prenatal diagnosis to select a male fetus for a couple with 4 daughters and no sons. Sex selection is the major use of prenatal diagnosis in India. The majority in the U.S.A. (62%) and Hungary (60%) would also do sex selection or refer. We discuss possible means of preventing sex selection while avoiding medical paternalism and promoting the autonomy of women.

Attitude↗
PubMed1990

A polymorphic satellite sequence maps to the pericentric region of the bovine Y chromosome.

Exploiting a serendipitously observed bovine male-specific signal, generated by the mouse pSP64.2.5EI minisatellite probe, we have cloned a bovine (Bos taurus) Y-specific sequence: btDYZ-1. This sequence is composed of 60 tandem repetitions of a motif consisting of two parts: a 40-bp-long unit, showing a mean divergence of 27% between repeats, separated from the next repeat by a TG-rich stretch varying in length between 12 and 63 bp. The number of copies of this repeated motif has been estimated at 6 X 10(4) per male genome. As a consequence, the corresponding satellite, DYZ-1, might represent approximately 1/20 of the bovine Y chromosome. btDYZ-1 has been mapped by in situ hybridization to the pericentric region of the Y chromosome. It is characterized by a substantial genetic polymorphism and has been shown to be conserved within the Bos and Bison genera of the Bovinae subfamily. This sequence is being used to develop a sexing procedure for bovine preimplantation embryos based on the polymerase chain reaction.

Animals↗
PubMed1991

Isolation of bovine Y-derived sequence: potential use in embryo sexing.

To obtain bovine Y-derived probes, we have constructed a bovine plasmid library enriched for Y-specific DNA sequences by the deletion enrichment method. The resulting clones were analyzed by hybridization to Southern blots of male and female genomic DNA. From 200 clones tested, two (BC1.2 and BC1.34) were entirely male specific, six gave a male-female differential hybridization pattern, and the remaining reacted similarly with male and female DNA. Interspecies somatic cell hybrid studies and chromosomal in situ hybridization confirmed that the BC1.2 sequence was derived from the Y chromosome. This 54-bp fragment is present at about 2000-2500 copies in the bovine male genome. No polymorphism was revealed with any of the restriction enzymes used, suggesting enzyme site conservation within blocks of repeats. Evolutionary study has shown that the BC1.2 sequence is conserved within Bos and Bison genera and remains male specific. The male specificity and repeated nature of the BC1.2 sequence have enabled us to use it as a molecular probe for sex determination on small numbers of cells by in situ hybridization.

Animals↗
PubMed2004

Gender selection: pressure from patients and industry should not alter our adherence to ethical guidelines.

Patients who undergo assisted reproduction occasionally request that physicians intervene with techniques that help to determine the gender of their offspring. Conventionally, all of these methods require an invasive procedure that places both the mother and pregnancy at risk. However, for sex-linked disorders, the risk/benefit ratio is favorable; therefore, in such cases, gender selection is warranted. The recent introduction of noninvasive techniques for X- and Y-chromosome-bearing sperm sorting now provides another option for couples. However, the method is not absolute in its ability to sort sperm correctly; in many cases, the offspring are not of the desired sex. Sperm sorting has been marketed increasingly as a means for "family balancing," which is contrary to recommendations that are offered by ethics committees of several professional societies. More studies are needed with respect to the impact of gender selection on families before this method is introduced into routine practice.

Ethics, Medical↗
PubMed2005

Low semen dose intracornual insemination of cows at fixed time after PGF2alpha treatment or at spontaneous estrus.

The numbers of spermatozoa per insemination and the site of semen deposition in the uterine horn appear to interact to influence pregnancy rate. In two experiments, the effect of a single low dose (2 x 10(6) spermatozoa) intracornual insemination (LD-ICI) on bovine pregnancy rate was compared with that of intracornual (SD-ICI) and conventional (SD-AI) inseminations of 40 x 10(6) spermatozoa. In Experiment 1, 157 cows were treated twice with PGF(2)alpha at a 14-day interval and inseminated at a fixed time (80-82 h) after the second PGF(2)alpha injection using LD-ICI (n=44), SD-ICI (n=61) or SD-AI (n=52). In LD-ICI and SD-ICI groups, semen was deposited in the horn ipsilateral to the ovulatory follicle close to the utero-tubal junction (LD-ICI-UTJ, n=33 and SD-ICI-UTJ, n=41) or in the middle part of the horn (LD-ICI-MH, n=11 and SD-ICI-MH, n=20). Pregnancy rates after LD-ICI-UTJ, LD-ICI-MH, SD-ICI-UTJ and SD-ICI-MH were 27%, 27%, 39% and 35%, respectively (P>0.05). The total pregnancy rate after LD-ICI (27%) did not differ (P>0.05) from that after SD-ICI (37%) or SD-AI (34%). In Experiment 2 (field trial), 362 cows were allotted, at spontaneous estrus, to LD-ICI-UTJ (n=86), LD-ICI-MH (n=97) or SD-AI (n=179). Pregnancy rates after LD-ICI and SD-AI were 47% and 45%, respectively (P>0.05). After LD-ICI-UTJ, the pregnancy rate (54%) did not differ significantly (P>0.05) to that obtained after LD-ICI-MH (41%) and after SD-AI (45%). The results of the study show that the single intracornual insemination of cows with 2 x 10(6) spermatozoa at fixed time, 80-82 h after the second PGF(2)alpha injection or at spontaneous estrus resulted in similar pregnancy percentage as intracornual and conventional inseminations with 40 x 10(6) spermatozoa per semen dose. With intracornual insemination using low or standard dose of spermatozoa, the pregnancy rates were not significantly affected by the exact site of semen deposition in the uterine horn, near the utero-tubal junction or in the middle part.

Animals↗
PubMed2006

Identification of X- and Y-chromosome bearing buffalo (Bubalus bubalis) sperm.

The aim of this study was to identify the difference in DNA content characterizing the X- and Y-chromosome bearing sperm of buffalo. Sperm from six Murrah buffaloes and six Nili-Ravi buffaloes were collected and stained with Hoechst 33342 followed by flow cytometry analysis of the DNA content. Two symmetrical, separate but overlapping peaks presumed to be X- and Y-chromosome bearing sperm were detected. The difference in fluorescence intensity, which related to the DNA content, between the X- and Y-sperm was 3.59+/-0.11% for Murrah buffalo and 3.55+/-0.14% for Nili-Ravi buffalo, respectively. Significant differences were observed among males within each breed, but there were no differences between the averages of the two breeds. The results indicate that flow cytometric sorting of X- and Y-sperm of buffalo is feasible.

Animals↗
PubMed2006

Non-surgical deep intra-uterine transfer of in vitro produced porcine embryos derived from sex-sorted frozen-thawed boar sperm.

Embryos and offspring of a pre-determined sex have been produced in pigs using AI and IVF with unfrozen sperm, and after surgical insemination with sex-sorted frozen-thawed sperm. The aims of this study were to demonstrate that sex-sorted frozen-thawed boar sperm could be incorporated into pig IVF for the production of embryos of a pre-determined sex and that these embryos could be successfully non-surgically transferred. Oocytes were matured in vitro, fertilised with either unsorted or sex-sorted frozen-thawed sperm and cultured until the eight-cell stage. These embryos were then transferred to recipients (n = 7) non-surgically (n = 70 embryos per sow). Oocyte cleavage was similar between sex-sorted (1538/5044; 30.5%) and unsorted (216/756; 28.6%) frozen-thawed sperm, and PCR sex-determination of the embryos confirmed that they were of the predicted sex (n = 16). Delayed return to oestrus (>23 days) was observed in five recipient sows (71.4%). Fetal sacs were observed by transcutaneous ultrasound on Day 18 in one of these sows. Pre-sexed porcine IVP embryos can be successfully produced using sex-sorted frozen-thawed boar sperm, and these embryos are capable of initiating pregnancies when transferred to recipients. However, further refinement of porcine ET protocols are required to enable development to term.

Animals↗
PubMed2006

Changing opinions of Mexican geneticists on ethical issues.

BACKGROUND: The discussion of ethical issues in the practice of medical genetics is quite recent in Mexico. However, in the present report we were able to compare the results obtained with the same instrument in two surveys performed with a 12-year interval. METHODS: A semistructured questionnaire including 52 questions that explore many different situations in the form of case vignettes related to ethical dilemmas was sent on two occasions to geneticists certified by the Mexican Board of Human Genetics. The first survey was performed in 1993, obtaining a response rate of 72% (64 individuals) and the second in 2005 with a 61% response rate (86 individuals). The areas explored were fairness of access to genetic services, full disclosure of all relevant information, respect for parental choices, protection of patients' privacy, use of prenatal diagnosis only for information about the health of the fetus, voluntary vs. mandatory screening and patients' confidentiality vs. the defense of third party interests. RESULTS: All questions analyzed in the paper were answered by at least 80% of the geneticists surveyed, although in many instances their experience with the situation explored was limited. The complete results of the 2005 survey are given in the text and tables, whereas the 1993 results are used mainly for comparison and given in full only when practical. There was a tendency to answer general questions one way and later change opinions when confronted with specific cases. There was a clear paternalistic attitude and a generalized opinion that one of the goals of medical genetics is to diminish the proportion of individuals with genetic diseases, not for eugenics reasons, but to avoid suffering of the patients and their families. CONCLUSIONS: Comparison of both surveys clearly shows a tendency towards increasing respect for privacy and autonomy of the patients.

Attitude of Health Personnel↗
PubMed2006

Advanced insemination techniques in mares.

Advanced artificial insemination techniques, such as deep uterine,hysteroscopic, oviductal, and intrafollicular insemination, are described in the context of the different types of spermatozoa that are now available for insemination, including fresh, chilled, frozen,sex-sorted, and epididymal spermatozoa. The implementation of these new technologies answers and poses questions about the interactions of sperm and oocytes in vivo.

Animals↗
PubMed2005

Preimplantation sex selection demand and preferences in an infertility population.

OBJECTIVE: To determine the demand and preferences of infertility patients for sex selection and the method and sex they would choose, and to investigate the relationship between these choices and their demographic and socioeconomic characteristics. DESIGN: Cross-sectional survey. SETTING: University hospital-based fertility center. PATIENT(S): One thousand five hundred consecutive women who presented for infertility care. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Self-report questionnaire assessing the demand and preferences for sex selection. RESULT(S): Of respondents, 40.8% wanted to select the sex of their next child for no added cost. Of these patients, 45.9% had no living children and 48.4% had children all of one sex. After adjustment for observed predictors of gender preference, we found a significant preference for a female child among women who were older, not religious, willing to pay for sex selection, had more living children, had only sons, or had a diagnosis of male infertility. Nulliparous women did not significantly prefer one sex over the other. Among parous women, those with only daughters significantly desired to select a male child, whereas those with sons significantly desired to select a female child. In terms of the method of sex selection, 55.0%, 41.0%, and 4.0% of the patients would use sperm separation, preimplantation genetic diagnosis, or neither method, respectively. CONCLUSION(S): There is significant demand among infertility patients for preimplantation sex selection, with a significant portion of this demand coming from patients who do not have any children or have children all of one sex.

Adult↗
PubMed2005

Preimplantation genetic diagnosis: technological promise and ethical perils.

OBJECTIVE: To describe the ethical issues inherent to the current and foreseeable uses of preimplantation genetic diagnosis (PGD). DESIGN: Review of ethical principles and their application to PGD. SETTING: Academic medical center. PATIENT(S): None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A discussion of the current ethical perils surrounding the use of PGD, and a prediction of future ethical quandaries that will arise from the use of this technology. RESULT(S): Although PGD may be used to predict and prevent disease, it may also be used to determine nondisease traits. The ever-expanding ability of genetics to determine qualities of the preimplantation embryo continues to open up new ethical questions relating to the use of PGD for preimplantation diagnosis. CONCLUSION(S): Preimplantation genetic diagnosis is a powerful technique with many positive applications. As with all such new technologies, care should be taken to ponder the ethical implications of its use before routinely accepting PGD as a tool in the reproductive armamentarium.

Female↗
PubMed2005

Pregnancies and live births after trophectoderm biopsy and preimplantation genetic testing of human blastocysts.

OBJECTIVE: To compare multiple-cell trophectoderm biopsy for preimplantation genetic diagnosis (PGD) from day-5 blastocysts with previously published experience with day-3 cleavage-stage embryos. DESIGN: Retrospective review of laboratory and clinical experience. SETTING: Sydney IVF, a private clinic in Australia. PATIENT(S): Preimplantation genetic diagnosis (PGD) patients age < 44 years with at least one IVF blastocyst suitable for biopsy, recruited from January 2002 through August 2004. INTERVENTION(S): Biopsy of trophectoderm from blastocysts on day 5 or 6, with same-day PGD for mutation testing, translocation testing, aneuploidy screening or sex selection. Spare, normal biopsied blastocysts were cryostored for possible later transfer. MAIN OUTCOME MEASURE(S): Fetal heart-positive pregnancy rate and accumulating live birth rate after adding results from biopsied fresh and frozen blastocysts for particular couples. RESULT(S): In 231 started PGD treatment cycles, unambiguous results were obtained from 974 of 1,050 biopsied blastocysts (93%); all blastocysts survived the biopsy procedure by reconstitution of their blastocele. One hundred nineteen women (median age, 36 years) have had 127 blastocysts transferred fresh (fetal heart-positive implantation rate, 41%). Of 146 blastocysts cryostored, 27 have been thawed (all with > 50% cell survival) and 24 transferred (implantation rate, 26%). To date, 53 pregnancies have been delivered or are ongoing, with an additional 4 clinical miscarriages (7%) and 6 subclinical miscarriages (total miscarriage rate, including biochemical pregnancies, 16%). There were no twin pregnancies. CONCLUSION(S): With technically appropriate blastocyst culture and freezing, blastocyst biopsy and cryostorage and later transfer of biopsied blastocysts is shown to be a practical and probably preferable path to preimplantation genetic testing of embryos compared with cleavage-stage embryo biopsy, being accompanied by a high implantation rate (and hence more conducive to elective single embryo transfer) and by a low rate of twinning and miscarriage.

Aneuploidy↗
PubMed2004

Medfly promoters relevant to the sterile insect technique.

This review summarizes structural and functional studies on medfly promoters and regulatory elements that can be used for driving sex-specific, conditional and constitutive gene expression in this species. Sex-specific and conditional promoters are important for generating transgenic sexing strains that could increase the performance of the Sterile Insect Technique while strong constitutive promoters are necessary for developing sensitive transgenic marker systems. The review focuses on the functional analysis of the promoters of two male-specific and heat shock medfly genes. A special emphasis is put on the potential utility of these promoters for developing transgenic sexing strains.

Ceratitis capitata↗
PubMed2005

Sex selection: treating different cases differently.

This paper contrasts ethical approaches to sex selection in countries where discrimination against women is pervasive, resulting in selection against girl children, and in countries where there is less general discrimination and couples do not prefer children of either sex. National sex ratio imbalances where discrimination against women is common have resulted in laws and policies, such as in India and China, to deter and prevent sex selection. Birth ratios of children can be affected by techniques of prenatal sex determination and abortion, preconception sex selection and discarding disfavored embryos, and prefertilization sperm sorting, when disfavored sperm remain unused. Incentives for son preference are reviewed, and laws and policies to prevent sex selection are explained. The elimination of social, economic and other discrimination against women is urged to redress sex selection against girl children. Where there is no general selection against girl children, sex selection can be allowed to assist families that want children of both sexes.

Abortion, Induced↗