[The selective effect of therapeutic abortion when children thus eliminated are carriers of a recessive autosomic or x-chromosome-linked defect].
Explore the source record for details and available documents.
Abortion, Therapeutic↗
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.
Spontaneous abortion: the role of heterogeneous risk and selective fertility.
The study of spontaneous abortion risk is complicated by the fact that a woman's successive pregnancies are not independent events. Non-independence may distort any analysis of spontaneous abortion risk that includes successive pregnancies. In order for an analysis of spontaneous abortion to take non-independence into account, a model must be developed. Previous attempts to describe non-independence have focused on the closely-related issue of whether the risk of abortion increases with successive pregnancies (i.e., with gravidity). Authors using various analytic strategies have reached conflicting conclusions about the gravidity effect. We review these attempts in detail, and in so doing, develop a synthesized viewpoint. We conclude that three factors powerfully affect the occurrence of spontaneous abortion: (1) a heterogeneous risk of abortion (constant for each woman but differing among women); (2) selective fertility (a tendency to control fertility on the basis of previous pregnancy outcomes); and (3) increased risk with maternal age. We demonstrate with a simulation model that these three factors alone can produce a spurious gravidity effect of a size similar to the effect found in actual data. Furthermore, we propose that these three factors offer a framework for a generalized analytic approach to spontaneous abortion, one that takes into account the non-independence of successive pregnancies.
Abortion, Spontaneous↗
Morphology and entry of enveloped and deenveloped equine abortion (herpes) virus.
Selective removal of the envelope of equine abortion (herpes) virus was accomplished by utilizing the nonionic detergent Nonidet P-40 followed by sonic treatment. The deenveloped particles differ significantly in size and buoyant density from the enveloped form. The cellular entry of purified enveloped and purified deenveloped virus was examined by electron microscopy during critical time periods. Both forms appeared to enter cells by a viropexis mechanism in which particles were engulfed by pseudopodia which either surround the virus and fuse with the cell membrane or to other pseudopodia, forming fusion vacuoles containing from one to numerous viral particles. This mode of entry was noted extensively at 5 min postinoculation. Deenveloped particles were apparently infectious only for hamsters, with a large inoculum being required. Contamination by enveloped forms was not noted after exhaustive search by electron microscopy.
Animals↗
State legislation on abortion after Roe v. Wade: selected constitutional issues.
Over the past three years, a great volume of legislation on abortion has been produced by state legislatures in an attempt to fill the vacuum created by the United States Supreme Court's 1973 decision in Roe v. Wade. This Article examines several of the most common types of statutory provisions and assesses their constitutionality in light of Roe v. Wade and other applicable federal and state legal standards.
Aborted Fetus↗
Transferrin C subtypes in extremely premature newborn infants.
Genetic typing of serum transferrin was performed in a group of 88 extremely premature infants (gestation age less than 32 wk) and in a control group of 351 full-term infants, using isoelectric focusing technique on ultrathin layer of polyacrilamide gel. A major incidence of C2 type was found among the preterm infants when compared to full-term infants X2 = 22,86, (P less than 0.001). In view of the previously reported higher incidence of this phenotype in women prone to spontaneous abortion, a selective mechanism associated with this serum transferrin type promoting spontaneous abortion and preterm delivery, seems to occur. The relative risk of preterm delivery were calculated to 1.4 and 8.3 for the C2-1 and C2 types, respectively. Supportive evidence in favour of this hypothesis is offered by the correlation existing between transferrin C2 allele and placental alkaline phosphatase variant F, the latter being associated with increased risk of spontaneous abortion.
Female↗
Son preference, sex selection, and the "new" new reproductive technologies.
Throughout recorded history, humans have tried to influence the sex of their offspring, through pregnancy injunctions, infanticide, and infant/child neglect. Reproductive technologies developed in the late 20th century allow determination of the sex of the offspring during pregnancy, making "sex selection" through abortion possible. Especially in parts of East and South Asia, sex selection against female fetuses has had dramatic consequences for male/female sex ratios. However, "newer" new reproductive technologies, such as prenatal genetic diagnosis and DNA-weighted semen selection, can now be applied for sex selection; eventually, the latter technology may become easily accessible as a noninvasive method. The prospects of these new technologies for sex selection must be considered in the light of cultural values surrounding son preference / daughter discrimination in many parts of the world, most notably Asia, as well as preferences for a "gender-balanced" family in much of the West. The ethical issues surrounding these technologies, such as the right to life and the equal treatment of female children, are potentially profound, but legislating the appropriate use of these "newest" new reproductive technologies will be difficult.
Asia↗
Public opinion and legal abortion in New Zealand.
In 1972 and 1974 opinions on legal abortion were surveyed over national random probability samples each of 2400 respondents aged 15 years and above. Both surveys found majorities favouring certain specific grounds for legal abortion. Some of these reasons approved by the majority are not legal under present law. There is a general consensus in the rank ordering of acceptability of grounds for legal abortion. Polarised minorities of respondents favour absolute legality or illegality of abortion. There has been a swing away from extreme pro- or anti-abortion sentiment to selective support for legal abortion on specific grounds.
Abortion, Legal↗
Women's perceptions on medical abortion.
The reasons why women choose medical abortion vary in different countries. In most countries, the most common reasons for choosing medical abortion are as follows: (a) avoidance of surgery or general anesthesia; (b) perception that it is safer; and (c) perception that it is more natural than a surgical procedure. In most studies, over 80% of women who chose medical abortion found it acceptable and would choose the same method again if they needed another abortion in the future. They would also recommend this procedure to other women who need an abortion. In selected women, the administration of misoprostol at home was also acceptable. The acceptability of medical abortion may decrease with increasing gestational age of pregnancy, failure of medical abortion, prolonged bleeding and high levels of discomfort and anxiety during the abortion procedure. There was no significant difference in the emotional responses or incidences of psychiatric morbidity between women undergoing medical and women undergoing surgical abortion.
Abortion, Induced↗
Abortions that fail.
In this study of 33,090 suction curettage abortions performed at less than or equal to 12 weeks' gestation, the rate of unrecognized failed abortions was 2.3 per 1000 abortions. Women with one or more prior pregnancies and those having an abortion at less than or equal to six weeks' gestation, particularly when small suction cannulae were used, were at higher risk for this complication (relative risks of 2.2, 2.9, and 11.1, respectively). Failures were also more likely when abortions were performed by resident physicians (relative risk of 2.2) and when they were performed on women with uterine anomalies (relative risk of 90.6). Physicians can minimize the risk of failed abortion by selecting an appropriate suction cannula size and by planning the optimal time to perform the abortion. Likewise, abortions performed either by residents or on women with uterine anomalies merit extra care.
Abortion, Legal↗
Adverse events that are associated with the selective estrogen receptor modulator levormeloxifene in an aborted phase III osteoporosis treatment study.
OBJECTIVE: Selective estrogen receptor modulators are novel compounds that bind to the estrogen receptor and have mixed agonistic and antagonistic activities. Recently, an increase in urinary incontinence has been reported with hormone replacement therapy use. A decrease in surgical procedures for pelvic floor relaxation has been recently reported with raloxifene, a selective estrogen receptor modulator that is not uterotropic. Levormeloxifene is a selective estrogen receptor modulator that was developed for the purpose of the treatment and prevention of postmenopausal osteoporosis. STUDY DESIGN: This was a multicentered prospective study of healthy women aged >or=65 years with osteoporosis who were randomized to blindly receive placebo or levormeloxifene 0.5 mg or 1.25 mg daily as part of a planned 3-year osteoporosis treatment study. Multiple medical and gynecologic evaluations were performed. Adverse events were reported to investigators and coded with the use of World Health Organization terminology. This study was halted after 10 months because of the large number of gynecologic and other adverse events. RESULTS: Among 2924 women who were studied, those women who were treated with levormeloxifene had a marked increase compared with placebo in leukorrhea (30% vs 3%), increased endometrial thickness on ultrasound scan (19% vs 1%), enlarged uterus (17% vs 3%), uterovaginal prolapse (7% vs 2%), urinary incontinence (17% vs 4%), increased micturition frequency (9% vs 4%), lower abdominal pain (17% vs 6%), hot flushes (10% vs 3%), and leg cramps (6% vs 0.8%). All of these differences were highly statistically significant with a probability value of.0001 for each. CONCLUSION: Levormeloxifene results in multiple adverse gynecologic and other events in postmenopausal women with osteoporosis.
Abdominal Pain↗
[Repeat abortion--utilization and social influences].
The frequency of repeat abortions in the institution from 1972 to 1987 was analysed. In order to assess occurrence in the area, epidemiological characteristics were developed and their changes described in chronological order. Above all, the relationship between repeat abortion and selected social factors on influence was investigated. The effects of the practised system of care to reduce abortion frequency can be seen in the low rates and numbers of repeat abortions. The results of the investigation into repeat abortion enable clues to be deduced that can help in further reducing such repeat abortions.
Abortion, Legal↗
Surgical techniques of uterine evacuation in first- and second-trimester abortion.
Induced abortion is an ancient procedure. Vacuum curettage is a recent innovation and is demonstrably superior to other methods for first-trimester abortions. Patient selection, patient preparation and the necessary instruments are described. The only absolute contraindications for local anaesthesia, vacuum curettage abortions are pregnancies too far advanced and allergy to local anaesthestics. The only mandatory laboratory tests are Rh blood group and cervical culture for gonorrhoea. Rh-negative patients must receive anti-D (Rh0) immunoglobulin. Perioperative antibiotics are of proven benefit. The technique of first-trimester vacuum curettage is described in detail here. The technique for very early abortion with the Karman cannula is also described. Fresh examination of tissue is critical after any abortion in order to rule out incomplete or missed abortion and to detect ectopic or molar pregnancy. Management of suspected perforation, haemorrhage, post-abortal syndrome and failed abortion are described. Dilation and evacuation (D&E) is the safest technique for mid-trimester abortion, especially when performed at 13-16 weeks. Some mid-trimester techniques are reviewed and the technique we follow is described in detail. Laminaria tents are left in place overnight, and the procedure is performed under paracervical block with intravenous sedation using low doses of diazepam and fentanyl. Evacuation is by means of large-bore vacuum cannula system and large ovum forceps. General anaesthesia is avoided because it increases the risk of perforation and haemorrhage. Adjuncts to D&E are described: intraoperative real-time ultrasound, intracervical vasopressin, two days' treatment with laminaria tents, and Hern's technique combining laminaria with intra-amniotic infusion of urea prior to D & E.
Abortion, Induced↗
The development of functionally responsive T cells.
The work reviewed in this article separates T cell development into four phases. First is an expansion phase prior to TCR rearrangement, which appears to be correlated with programming of at least some response genes for inducibility. This phase can occur to some extent outside of the thymus. However, the profound T cell deficit of nude mice indicates that the thymus is by far the most potent site for inducing the expansion per se, even if other sites can induce some response acquisition. Second is a controlled phase of TCR gene rearrangement. The details of the regulatory mechanism that selects particular loci for rearrangement are still not known. It seems that the rearrangement of the TCR gamma loci in the gamma delta lineage may not always take place at a developmental stage strictly equivalent to the rearrangement of TCR beta in the alpha beta lineage, and it is not clear just how early the two lineages diverge. In the TCR alpha beta lineage, however, the final gene rearrangement events are accompanied by rapid proliferation and an interruption in cellular response gene inducibility. The loss of conventional responsiveness is probably caused by alterations at the level of signaling, and may be a manifestation of the physiological state that is a precondition for selection. Third is the complex process of selection. Whereas peripheral T cells can undergo forms of positive selection (by antigen-driven clonal expansion) and negative selection (by abortive stimulation leading to anergy or death), neither is exactly the same phenomenon that occurs in the thymic cortex. Negative selection in the cortex appears to be a suicidal inversion of antigen responsiveness: instead of turning on IL-2 expression, the activated cell destroys its own chromatin. The genes that need to be induced for this response are not yet identified, but it is unquestionably a form of activation. It is interesting that in humans and rats, cortical thymocytes undergoing negative selection can still induce IL-2R alpha expression and even be rescued in vitro, if exogenous IL-2 is provided. Perhaps murine thymocytes are denied this form of rescue because they shut off IL-2R beta chain expression at an earlier stage or because they may be uncommonly Bcl-2 deficient (cf. Sentman et al., 1991; Strasser et al., 1991). Even so, medullary thymocytes remain at least partially susceptible to negative selection even as they continue to mature.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Issues in evolutionary medicine.
This paper illustrates the utility of applying evolutionary thought to medical issues with three examples: selection arenas, aging, and tradeoffs. First, the human female reproductive tract functions as a selection arena at two levels: in the ovaries, where atresia reduces the number of oocytes by more than 99.99% before any are ovulated, and in the uterus, where early embryos homozygous for immune genes are spontaneously aborted. These selective filters early in life have implications both for eugenics and for the anti-abortion movement. Second, the evolutionary theory of aging predicts that intrinsic mortality should reflect extrinsic mortality: if life for adults is risky, then it does not pay to invest in maintenance at the expense of reproduction. This idea is well confirmed, at least in populations where density effects are not important. While only organisms that reproduce asymmetrically should age, even bacteria reproduce asymmetrically, and they do age, suggesting that all organisms reproduce asymmetrically and therefore age. Third, tradeoffs are central to theories of phenotypic design, but the mechanisms that cause them remain obscure. A method is suggested to get at the mechanisms of tradeoffs by examining conflicts among functions over gene expression. It could be applied in humans to the tradeoff between reproductive performance and disease resistance.
Aging↗
Blood transfusions generate/increase previously absent/weak blocking antibody in women with habitual abortion.
Women who suffered recurrent spontaneous abortions of unknown cause were studied for cellular reactivity and blocking antibody in a one-way mixed lymphocyte culture. A defined group of 20 women whose serum displayed no blocking capacity was given three transfusions of leukocyte-rich erythrocyte concentrates. Serum from all women displayed significant blocking capacity 2 months after the third transfusion. Because blocking antibody seems to be one of the necessary prerequisites for successful pregnancy, leukocyte transfusions from third-party donors ought to be an effective cure for habitual abortion in selected cases.
ABO Blood-Group System↗
Characteristics of repeat aborters in Vietnam.
Two hundred and sixty married women seeking induced abortion service in Hanoi, Vietnam were interviewed to determine the magnitude of repeat induced abortion and explore selected characteristics of the repeat aborters. Seventy-one percent of the sample reported having had at least one previous induced abortion. After adjustment for age and number of living children, poor attitudes toward contraception, low use of modern contraceptives and failure of contraception were shown to be significantly associated with repeat induced abortion. Woman's age, number of living children, contraceptive knowledge and experience and desire for no more children were positively related to repeat induced abortion. Socio-demographic characteristics were not related to repeat induced abortion. Improvement of attitudes toward contraception, persuasion to use modern contraception and promotion of contraceptive effectiveness are recommended strategies to prevent repeat induced abortion.
Abortion, Induced↗
Abortion in adolescence.
This article reviews the difficult but complex subject of abortion in adolescents. Methods of abortion are outlined and additional aspects are presented: psychological effects, counseling issues, and legal parameters. It is our conclusion that intense efforts should be aimed at education of youth about sexuality and prevention of pregnancy, utilizing appropriate contraceptive services. When confronted with a youth having an unwanted pregnancy, all legal options need to be carefully explored: delivery, adoption, or abortion. The decision belongs to the youth and important individuals in her environment. Understanding developmental aspects of adolescence will help the clinician deal with the pregnant teenagers. If abortion is selected, a first trimester procedure is best. Finally, physicians are urged to be aware of the specific, ever changing legal dynamics concerning this subject which are present in their states. Abortion is a phenomenon which has become an emotional but undeniably important aspect of adolescent sexuality and adolescent health care, in this country and around the world.
Abortion, Induced↗
Attitudes toward abortion as a means of sex selection.
A questionnaire was administered to 317 unmarried male and female college students in order to determine the acceptability of abortion as a means of achieving offspring of a desired sex. Respondents were given three hypothetical situations (first, second, and last child) to rate, comparing the present method of amniocentesis followed by abortion with proposed simpler methods. Acceptance ranged from 4.2% to 40.3%, being greatest among the less religious, male, and Protestant respondents. Proposed methods were only slightly more acceptable than the present one. Thus, simplifying the abortion procedure for the purpose of sex selection would not appear to increase its acceptability or utilization.
Abortion, Induced↗