SEARCH · PubMed Health

Results for “Abortion, Selective”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 145 records · Page 8Linked to original sources

PubMed1992

Transvaginal embryo aspiration--a safe method for selective reduction in multiple pregnancies.

OBJECTIVE: To evaluate pregnancy outcome after transvaginal selective embryo aspiration and to compare the results with those reported previously with other techniques for selective abortion. DESIGN: Retrospective case series. SETTING: University-based in vitro fertilization (IVF) program. PATIENTS: Nineteen women with multiple pregnancy who conceived after ovulation induction or IVF/gamete intrafallopian transfer. INTERVENTION: Transvaginal ultrasound-guided aspiration of the embryo(s) was performed at 7 to 8 weeks of gestation. MAIN OUTCOME MEASURES: Early and late complications related to the procedure, outcome of pregnancy, and birth weight. RESULTS: In 18 cases, the initial number of embryos (3 to 7) was reduced to two. In 1 case, the number of embryos was reduced from 4 to 3. None of the remaining fetuses vanished after the procedure. One patient delivered at 25 weeks and all other patients delivered healthy, viable infants (a pregnancy loss rate of 5.3%). CONCLUSIONS: Transvaginal embryo aspiration in early gestation appears to be a simple and relatively safe procedure for selective termination in patients with high-order multiple pregnancy. The cumulative loss rate of selective termination procedures previously reported by others is three times higher than the loss encountered in our series. This earlier procedure may be more acceptable to patients from emotional and religious points of view.

Abortion, Induced↗

PubMed2002

Increased heterozygosity for MHC class II lineages in newborn males.

In plants, fungi and marine invertebrates, there are genetic compatibility systems to ensure diversity in the offspring. The importance of genetic compatibility in gametic union and selective abortion in vertebrate animals has also been appreciated recently. There have been suggestions that the major histocompatibility complex (HLA in humans) may be a compatibility system in vertebrates. HLA class II haplotypes often contain a second expressed DRB locus which can be either DRB3, DRB4 or DRB5. These encode the supertypical specificities and mark the ancestral lineages. The members of each lineage have related DNA sequences at the main class II locus HLA-DRB1. We analysed 415 newborns at all expressed DRB loci by PCR analysis to seek evidence for sex-specific prenatal selection events. While there was no significant change in heterozygosity rates between males and females at DRB1, the proportion of males carrying two DRB1 specificities from different ancestral lineages was significantly increased (53.7% in males vs 39.3% in females, P = 0.003). The genotypes consisting of phylogenetically most distinct ones, namely the DRB3 and DRB4 haplotypes, showed the most striking difference between sexes (P = 0.007). These results suggested a more favourable outcome for male concepti heterozygous for supertypical haplotypes. Heterozygosity for most divergent haplotypical families ensures the highest degree of functional heterozygosity at the main HLA class II locus DRB1 while increasing the likelihood of heterozygosity also at other MHC loci. Our observations agree with the previously reported heterozygote excess in male newborn rats and mice. Correlations between MHC class II heterozygosity and advertised male quality in deer and pheasant as well as increased reproductive success in MHC class II heterozygous male macaques are examples of postnatal benefits of heterozygosity in males that may be behind the development of prenatal selection mechanisms. The MHC-mediated prenatal selection of males may also be one of the selective events suggested by the very high primary (male-to-female) sex ratio at fertilization reaching close to unity at birth in humans. These results provide an appealing working hypothesis for further studies in humans and other vertebrates.

Alleles↗

PubMed1999

Apical pattern of fruit production in the racemes of Ceratonia siliqua (Leguminosae: Caesalpinioideae): role of pollinators.

Fruit production and arrangement within the raceme were studied in two dioecious populations of Ceratonia siliqua (Leguminosae: Caesalpinioideae), an arboreal species that produces caulogenous racemes (emerging only from the old branches) with numerous flowers. Fruit production per raceme was low and similar between years and populations and even between individuals. During flowering, there were considerable flower losses from predation and lack of pollination. A mean of nine flowers per raceme began the transformation into fruits, of which 77% aborted. The final fruit production per raceme increased significantly following hand pollination, but was always very much lower than the availability of flowers in the raceme. The results suggest that fruit production of each raceme is limited by both availability of resources and a deficient pollination. In racemes setting fruit arrangement follows a definite pattern that remains constant between years and populations: fruit production was significantly higher in the apical zone of the raceme and lower in the basal zone. The pollinators of C. siliqua (flies and wasps) showed a clear preference for beginning their visits at the apex of a raceme. As a result, the pollen load deposited on the stigmas decreased from apex to base of the raceme. In most of the flowers situated in the central and basal zone of the raceme, the number of pollen grains deposited on their stigmas was lower than the number of their ovules. The high number of seeds in developed fruits suggests that the plant selectively aborts flowers that receive a smaller pollen load. The results indicate that the final pattern of fruit arrangement within the raceme is a direct result of pollinator activity.

Journal Article↗

PubMed1996

Non-random fertilization in mice correlates with the MHC and something else.

One evolutionary explanation for the success of sexual reproduction assumes that sex is an advantage in the coevolutionary arms race between pathogens and hosts. Accordingly, an important criterion in mate choice and maternal selection thereafter could be the allelic specificity at polymorphic loci involved in parasite-host interactions, e.g. the MHC (major histocompatibility complex). The MHC has been found to influence mate choice and selective abortions in mice and humans. However, it could also influence the fertilization process itself, i.e. (i) the oocyte's choice for the fertilizing sperm, and (ii) the outcome of the second meiotic division after the sperm has entered the egg. We tested both hypotheses in an in vitro fertilization experiment with two inbred mouse strains congenic for their MHC. The genotypes of the resulting blastocysts were determined by polymerase chain reaction. We found nonrandom MHC combinations in the blastocysts which may result from both possible choice mechanisms. The outcome changed significantly over time, indicating that a choice for MHC combinations during fertilization may be influenced by one or several external factors.

Animals↗

PubMed1983

Chromosome abnormalities and spontaneous fetal death following amniocentesis: further data and associations with maternal age.

The pooled results are presented of two North American surveys concerning spontaneous fetal deaths of conceptuses with cytogenetic abnormalities diagnosed prenatally whose mothers had declined elective abortion. The rate of fetal death of those with nonmosaic genotypes associated with Down syndrome was 30.1% (95% confidence interval of 19.0%-42.0%), which is almost identical with the difference of 30% previously estimated between rates observed at amniocentesis and in live births. The fetal death rate for (nonmosaic) 47,+18 was 68.0% (95% confidence interval of 46.5%-85.1%), close to the estimated difference of 75% between rates at amniocentesis and in live births for this genotype. For other nonmosaic genotypes, the rates (and 95% confidence intervals) were: 47,+13, 42.9% (9.9%-81.6%); 47,XXX, 0% (0%-9.0%); 47,XXY, 8.1% (0.8%-11.0%); 47,XYY, 3.0% (.08%-15.8%); for balanced translocations and inversions, 2.8% (0.3%-9.8%); and for markers, variants, and fragments, 0% (0%-12.8%). For 45,X, the rate was 75.0% (42.8%-94.5%), in contrast to the rate for 46,XX/45,X of 10.5% (1.3%-33.1%) and for structural X abnormalities associated with Turner syndrome of 0% (0%-60.2%). The rate for nonmosaic 45,X is significantly different from that for either of the other two categories associated with Turner syndrome. The maternal age of nonmosaic 47,+21 fetuses that survived to live birth was 39.1 +/- 6.2, not significantly different from the rate for fetal deaths: 39.5 +/- 3.8. The observations provide no support for opposing hypotheses by other groups that maternal age is positively or negatively associated with fetal death of 47,+21 conceptuses. For other chromosome abnormalities, maternal ages of fetal deaths are slightly lower than for live births, but none of the differences are significant. The rates of spontaneous fetal deaths derived here are likely to be pertinent to genetic counseling. Their use in adjusting the rates of abnormalities diagnosed at amniocentesis will enable derivation of predicted contemporary live-birth prevalence rates of abnormalities that would be observed in absence of selective abortion.

Adult↗

PubMed1993

Tomorrow's prenatal genetic testing. Should we test for 'minor' diseases?

New genetic knowledge will make it possible to test prenatally for a wide range of fetal genetic characteristics. One consequence will be an expansion of potential reasons for selective abortion following prenatal testing. It will likely become possible for patients to request prenatal testing and abortion not only for serious diseases but also relatively mild diseases, late-onset diseases, treatable diseases, elevated risks for common diseases, and eventually nondisease characteristics, such as height and body build. Two main ethical views concerning prenatal testing have been advocated: (1) Prenatal testing should be restricted to the "most severe" disorders, involving profound retardation, severe physical handicaps, or prolonged physical suffering and (2) Patients' requests for prenatal tests should be honored except for diseases considered to be "too minor." At least two additional views can be identified: (3) Physicians should honor requests for prenatal testing for diseases, including relatively minor ones, but not requests pertaining to nondisease characteristics and (4) All requests for prenatal tests should be honored. A difficulty with the first and second views is that they deviate from the norm of nondirectiveness in prenatal testing and counseling. The problems with the fourth view are that it leads to abortions for morally trivial reasons and that attempts to design our children could adversely affect parent-child relationships and exacerbate current social inequities. These considerations support the third view, which holds that the future role of reproductive genetic testing and counseling should be based on the imperfect, but helpful, distinction between disease and nondisease.

Ethics, Medical↗

PubMed1999

Genetic counseling for childless women at risk for Duchenne muscular dystrophy.

The aim of the present study was to assess the impact of genetic counseling in young women at risk to have Duchenne muscular dystrophy (DMD) children prior to childbearing. A total of 263 potential DMD carriers, who had had genetic counseling and were given different genetic risks, were included in this investigation. Their reproductive outcome and future plans as well as their requests for DNA tests (for carrier detection and prenatal diagnosis) were analyzed according to genetic risk magnitude, comprehension of genetic counseling is- sues, family and personal history, socio-educational level, and subjective opinion about selective abortion. We noted that genetic risk magnitude had no significant influence on reproductive plans or outcome nor on the request for additional DNA testing, even considering only those clients with good comprehension and retention of issues discussed during genetic counseling. On the other hand, counselees who had more than one affected or at least one deceased DMD case in their family understood genetic counseling significantly better, suggesting that "learning with life" has a stronger impact than genetic counseling.

Adult↗

PubMed1998

Non-disclosure preimplantation genetic diagnosis for Huntington's disease: practical and ethical dilemmas.

Prenatal diagnosis of Huntington's Disease (HD) is controversial. Selective abortion is considered unacceptable by some, since, being a late-onset disorder, any child born carrying the HD mutation might still expect many years of disease-free life. The test result itself has implications for the parents and other members of the family who may have decided not to be tested but who know that they may be at risk because a family member is affected. For this reason some potential carriers do not want to know their carrier status and may prefer prenatal exclusion testing. However, since half the fetuses carrying the affected grandparental allele may be normal, aborting these fetuses is also controversial. Preimplantation genetic diagnosis (PGD) has been suggested as an alternative by which asymptomatic individuals who are at high risk of carrying HD can avail themselves of antenatal genetic testing without incurring the emotional, social and financial burdens that might result from the presymptomatic disclosure of their own carrier status. However, non-disclosure testing of embryos in vitro presents specific practical difficulties. Assurance of absolute secrecy is difficult in the large team required for in vitro fertilization biopsy and diagnosis, and changes in practice which may be required to maintain the deception may be unethical.

Confidentiality↗

PubMed1994

Screening for neural tube defects.

The birth prevalence of neural tube defects fell by 95% in England and Wales between 1970 and 1990 largely as a result of antenatal screening, subsequent diagnosis and selective abortion of affected pregnancies. Anencephaly can be diagnosed using ultrasound, whereas both amniotic fluid biochemistry and ultrasound are required for the diagnosis of spina bifida. Both methods have a false-positive rate of about two per 1000 when carried out in high-risk pregnancies. The diagnostic results are likely to be better if the two methods are used in parallel. Maternal serum alpha-fetoprotein screening at 16-18 weeks gestation can detect about 75% of pregnancies affected by spina bifida. Routine ultrasound anomaly screening, usually performed at 18-20 weeks gestation, can detect a similar proportion. New developments indicate that earlier, more accurate detection may be possible but more research will be needed before this can be established.

Biochemistry↗

PubMed1990

First trimester selective reduction in multiple pregnancy guided by transvaginal sonography.

Transvaginal ultrasonography-guided fetal reduction was performed in 11 patients presenting with multiple pregnancies. Embryonic aspiration was carried out in 7 women at 7 to 8 weeks and in 4 patients fetal intrathoracic injection was performed at 9 to 11 weeks, menstrual age. Seven patients delivered healthy babies at greater than 35 weeks, 3 have delivered prematurely 15 to 17 weeks after the procedure with subsequent neonatal death of all sets of twins. We believe that our method overcomes the technical difficulties related to the transabdominal or transcervical approach and should be the method of choice for early selective abortion.

Abortion, Induced↗

PubMed1991

Prenatal diagnosis for Huntington's disease: a molecular and psychological study.

Two linked probes were used to determine the Huntington's disease status of the fetus conceived by a woman affected with the condition. The fetus was found to be unaffected with a certainty of 97 per cent. The ethical issues associated with presymptomatic testing were avoided since the mother presented with initial symptoms of Huntington's disease, but other psychological and ethical issues arose. The concerns of an affected woman planning a pregnancy, and the dilemmas involved in decision-making regarding prenatal diagnosis and possible selective abortion were exposed and explored with the patient and her husband.

Adult↗

PubMed1992

Preconception and preimplantation diagnosis for cystic fibrosis.

Preimplantation diagnosis provides couples at high genetic risk the possibility of avoiding genetic disease without the need for prenatal diagnosis and selective abortion of the affected pregnancy. Following extensive background work on the reliability of genetic diagnosis in a single cell, we offered on a research basis preimplantation diagnosis to five couples at risk for offspring with the delta-F508 mutation (the major mutation causing cystic fibrosis). There was no detrimental effect from polar body removal on either fertilization or preimplantation development. Genetic analysis, undertaken in 22 polar bodies and 15 corresponding blastomeres, identified 21 embryos of which ten were transferred.

Biopsy↗

PubMed2006

Conjoined twins--past, present, and future.

BACKGROUND/PURPOSE: Conjoined twins are rare and complex anomalies of the newborn. They require a highly experienced team and a center equipped to deal with such challenging anatomy. METHOD: A review of 31 sets of conjoined twins was managed by one team over a 15-year period. The spectrum of the anomalies, management strategies, and outcomes will be analyzed with future recommendations. RESULTS: Ten sets of complete conjoined twins and two sets of parasitic conjoined twins were successfully separated. Tissue expanders and prosthetic meshes were not required. A separation of one set of craniopagus parasiticus conjoined twins was attempted, but abandoned owing to major vascular and brain sharing. The remaining 18 sets were not separable owing to major cardiac anomalies and/or sharing, and all died within several weeks of birth. CONCLUSION: Careful planning, a multidisciplinary approach, rehearsal, and experience are important factors in dealing with conjoined twins. Tissue expanders and prosthetic meshes are not required in most cases. Selective abortion or fetal intervention may play a role in the future.

Follow-Up Studies↗

PubMed2006

Diagnostic significance of Neospora caninum DNA detected by PCR in cattle serum.

A nested PCR that successfully detected Neospora caninum DNA in serum of cattle was used for investigation of selected abortion cases and in a study of healthy pregnant cows at an abattoir. N. caninum DNA was not detected in serum from antibody positive dams that aborted due to N. caninum, but was present in serum of some antibody negative dams that aborted due to other causes. N. caninum DNA was also found in the serum of about half of the animals that aborted of undetermined cause, but was not detected in cow sera from two beef cattle herds in Western Australia with no recent history of abortion. In the abattoir study of 79 dams and their foetuses N. caninum DNA was found in serum of 3 dams and in material from 11 foetuses. The majority of the cows and all foetuses were antibody negative. Our findings suggest that there is no obvious relationship between the presence or absence of N. caninum DNA in serum and the presence of antibodies to N. caninum in dams, the presence of N. caninum DNA in foetuses or abortion due to N. caninum. This is the first report of the detection of N. caninum DNA in serum of cattle rather than the white blood cell fraction. It indicates the presence of free tachyzoites and/or parasite DNA in circulation. The results suggest that persistent infection in the absence of antibodies is a possible outcome of N. caninum infection. Infection of foetuses in the absence of antibodies supports the possibility of persistent infection due to immunotolerance to an early in utero infection. It is therefore important to test for N. caninum DNA as well as antibodies for the detection of exposed and/or infected animals. However, the presence or absence of N. caninum antibodies or DNA did not support nor exclude N. caninum as the cause of abortion. Additional criteria are required for a positive diagnosis of abortion caused by N. caninum.

Abattoirs↗

PubMed1986

Hormonal control of sex ratio.

It has been hypothesized that the maternal gonadotrophin level at the time of conception is causally related to the sex of the resultant human zygote, high levels of hormone being associated with the production of female offspring. In this note, evidence for and against this hypothesis is reviewed. There seems so much evidence in its favour that one might conclude that it contains at least a kernel of truth. It is suggested here that of the components of gonadotrophin, the active one in this hypothesized sex-selective process is luteinizing hormone, rather than follicle-stimulating hormone. The hypothesis is nevertheless unable to accommodate several well-established sets of data. Accordingly it is suggested that other hormones, oestrogen and testosterone, have sex-selective properties too, high levels being associated with male offspring. This elaboration of the hypothesis, if it were true, would explain most, if not all, of the epidemiological data on the human secondary sex ratio. In particular it would explain Guerrero's data which have hitherto resisted explanation of any kind. No suggestion is made about possible mechanisms underlying these hypothesized sex-selective properties. But it seems that sex-selective abortion is not the only one. It is hoped that other workers may be stimulated not only to test the hypothesis as outlined here, but--if it survives this testing--to suggest such mechanisms.

Adult↗

PubMed2002

Violence against women: global scope and magnitude.

An increasing amount of research is beginning to offer a global overview of the extent of violence against women. In this paper we discuss the magnitude of some of the most common and most severe forms of violence against women: intimate partner violence; sexual abuse by non-intimate partners; trafficking, forced prostitution, exploitation of labour, and debt bondage of women and girls; physical and sexual violence against prostitutes; sex selective abortion, female infanticide, and the deliberate neglect of girls; and rape in war. There are many potential perpetrators, including spouses and partners, parents, other family members, neighbours, and men in positions of power or influence. Most forms of violence are not unique incidents but are ongoing, and can even continue for decades. Because of the sensitivity of the subject, violence is almost universally under-reported. Nevertheless, the prevalence of such violence suggests that globally, millions of women are experiencing violence or living with its consequences.

Adult↗

PubMed1987

Clinic experience of prenatal diagnosis of cystic fibrosis by use of linked DNA probes.

96 families at risk of having a child with cystic fibrosis have been counselled about prenatal diagnosis by the use of linked DNA probes. Of the first 30 pregnancies 9 children have been born and confirmed to be free from CF, as predicted; 8 pregnancies were terminated (1 of these was found to be miscarrying at time of termination); 12 pregnancies, in which the fetuses are predicted to be unaffected, are in progress; and 1 has miscarried. No couple with a prenatal prediction of CF decided to continue with the pregnancy. 1 pregnancy was terminated because of a 50:50 chance of an affected fetus. In 1 twin pregnancy the affected fetus was selectively aborted, and the other baby was confirmed after birth to be unaffected, as predicted. In the other twin pregnancy the two chorionic plates could not be samples separately; the pregnancy was continued on the basis of normal findings for the lower plate, and both twins have turned out to be normal. Many couples at risk see early prenatal diagnosis as a way to help them have an unaffected child.

Abortion, Induced↗

PubMed2001

Sex selection in practice among Hong Kong Chinese.

The aim of this study is to identify factor(s) influencing imbalance in the sex distribution of children (more children of the same sex) of the multiparous women attending an antenatal clinic in Hong Kong. A retrospective study was carried out to compare the expected and observed sex ratios of babies born to women with one previous live birth and women with two. All singleton pregnant women of parities 1 and 2 delivering after 22 weeks of gestation, between 1 July 1996 and 30 June 1998, were included. A total of 2604 women of parity 1 and 752 women of parity 2 were included. The sexes of the children of parity 1 women and the sex distribution of their newborns were consistent with the predicted value. The parity 2 women were more likely to have third children if their previous children were of the same sex (p-value < 0.001). This implies that the parity 2 women attending our antenatal clinic had third pregnancies because of social, economical or environmental reasons. Our parity 2 women with two daughters were more likely to have sons (p < 0.05). Thus, biological or parental factors were unlikely to be important in influencing the sex of the newborn. This suggested that sex selection or sex-selective abortion might be practiced among Hong Kong Chinese women.

China↗