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Biomedical subjects

A Lippman-Hand

Publications and source records attributed to A Lippman-Hand.

16 recordsLinked to original sources
PubMed1983

Balanced translocations among couples with two or more spontaneous abortions: are males and females equally likely to be carriers?

Chromosome studies were performed on a series of 177 couples referred for genetic counseling following two or more spontaneous abortions to clarify the relationship between karyotype and fertility in males and females and to provide risk figures for genetic counseling. The results of these investigations, when combined with those in the literature, suggest that 2-3% of individuals in couples experiencing early fetal losses carry a balanced translocation and that this is not markedly influenced by the number of losses greater than two. Females are more likely than males to be the carrier, reflecting the fact that structural abnormalities of the chromosomes that are compatible with fertility in the female may be associated with sterility in the male. Karyotyping should be performed on both members of a couple following two spontaneous abortions and the products of conception should be studied whenever possible to begin to determine the biological basis of the association between parental rearrangement and fetal loss.

Abortion, Habitual↗
PubMed1982

Prevention of mental retardation in offspring of hyperphenylalaninemic mothers.

Maternal hyperphenylalaninemia constitutes a potential hazard to the fetus for whom the risks of postnatal mental retardation, microcephaly, and congenital malformations are elevated. Preconception and intragestational dietary treatment can apparently improve the outcome of such pregnancies. In the absence of predictive mechanisms for pregnancies at risk and preventive measures involving reproductive counseling and treatment, there could be a rebound in the population frequency of mental retardation related to disorders of phenylalanine metabolism in subsequent generations. We describe a program serving a population of six million that includes screening, diagnosis, treatment, and counseling of the hyperphenylalaninemias. The program has recently added a simple dedicated register for males and females with hyperphenylalaninemia to supplement traditional methods for continuous surveillance of probands. We registered 153 patients: 43 females and 56 males with phenylketonuria, 23 females and 31 males with benign hyperphenylalaninemia, of which 22, 7, 27 and 5, respectively, had reached their 12th birthday in an 1981. Regional centers in the program provided counseling about the consequences of maternal hyperphenylalaninemia and the options to prevent them. No family has rejected the principle or fact of the Register and its goals.

Adolescent↗
PubMed1982

Maternal-age effect in aneuploidy: does altered embryonic selection play a role?

The age of mothers of children with trisomy 21 (47,+21) is elevated no matter if the extra chromosome is of maternal or paternal origin, and it has been postulated that decreasing maternal selection against affected conceptuses with advancing age might explain this observation. Since the absence of sufficient data on 47,+21 abortuses precludes a direct test of this hypothesis, we have taken an indirect approach. Pooled data from spontaneous abortions and live births with autosomal trisomies, XXY and XXX, were examined to determine the natural history of these aneuploid conceptuses and its relation to maternal age. The results are consistent with decreasing embryonic selection in older women.

Abortion, Spontaneous↗
PubMed1981

Prenatal diagnosis for the detection of Down syndrome: why are so few eligible women tested?

Postpartum women greater than or equal to 33 years were interviewed about their attitudes to and knowledge and use of prenatal diagnosis. Overall, 68 per cent had heard of prenatal diagnosis: nevertheless, only 30 per cent of those greater than or equal to 35 had actually been tested. The only significant difference between eligible women who were tested and those who were not was maternal age. Of those tested, half requested it for themselves; conversely, only two thirds of women requesting the procedure actually received it. Among women not tested, 82 per cent were never offered the procedure by the physician. Expressed attitudes to prenatal diagnosis were strongly positive among all women, with 75 per cent continuing to want testing after learning both their age-specific risk of having an affected child and the possible risks of amniocentesis. The data document a potential demand for amniocentesis far in excess of current use and present service facilities. They suggest, moreover, that underuse may reflect professional hesitation and underreferral more than consumer lack of demand or reluctance to be tested.

Adult↗
PubMed1981

The convenience sample as a source of data in the study of Down syndrome.

Epidemiologic and health care research on Down syndrome are frequently based on cases known to a specific hospital, clinic or social service agency. To determine if there are any systematic differences between such readily available cases and their birth cohort that might impair their use for research, we compared a total population of children with Down syndrome live-born in Montreal in 1975 and 1976 (n = 88) with two convenience samples drawn from this population: cases known to a hospital genetic counselling centre and cases participating in an early intervention programme. Complete information on maternal age and parity, birth weight and sex of child, presence or absence of congenital heart disease and residential placement was obtained for eighty-three members of the cohort. Analysis revealed that the cases known to the genetic counselling centre were more likely to have younger mothers caring for them at home than the remaining cases in the Down syndrome population; children participating in an early intervention programme were also more likely to be residing in their natural homes than those cases in the remaining comparison population. The majority of potential cases from the original population were not included in either case group. The findings suggest that "convenience" samples differ significantly from their parent population and that caution is required when applying data generated from selected groups to the remaining population.

Adolescent↗
PubMed1980

Influence of obstetricians' attitudes on their use of prenatal diagnosis for the detection of Down's syndrome.

Practising obstetricians were surveyed to determine the relation between their referral patterns and their knowledge and attitudes concerning prenatal diagnosis by amniocentesis for women aged 35 years and over. Although 82% had referred at least one eligible patient for prenatal diagnosis during the past year, almost none had used the available services for all appropriate patients. There was a statistically significant trend for increased referral as correct knowledge of the risks and accuracy of prenatal diagnosis increased. Moreover, a discriminant function combining risk and accuracy estimates, type and size of practice, and language distinguished the referrers from the nonreferrers (P = 0.0002), although there was considerable overlap between the physicians classified according to a high, moderate or low rate of referral. The data suggest that while knowledge and practice characteristics can distinguish obstetricians who refer patients for prenatal diagnosis from those who never do so, the frequency of referral may involve other factors, such as how physicians accept innovation and perceive risks.

Adult↗
PubMed1979

Genetic counseling: provision and reception of information.

To explore verbal communication between family and counselor, transcripts of 30 tape-recorded or observed genetic counseling sessions are analyzed qualitatively. In half the cases, available data did not allow counselors to give parents a single estimate of the recurrence rate. Moreover, limits on the language available for communicating small probabilities made common the use of nonnumerical statements about a family's chance of having an abnormal child. Counselees processed the factual information they were given, most commonly translating recurrence rates in ways that emphasized the uncertainties associated with them. They tended to view these rates in binary form and requested guidelines for their behavior, indicating uncertainty about how to proceed with reproductive decision-making. The findings suggest that strategies for processing information are an important element influencing parental perspectives on and approaches to the problems created by being at-risk and to possible courses of action.

Attitude to Health↗
PubMed1979

Genetic counseling--the postcounseling period: I. Parents' perceptions of uncertainty.

To investigate how parents who have had genetic counseling perceive the problems created by being at risk, transcripts of open-ended, semistructured follow-up interviews with 53 counselees were analyzed qualitatively. Rate information, though recalled accurately by parents considering further childbearing, was discounted as impersonal, and subjects overwhelmingly perceived the chance of recurrence in binary form -- it either will or will not happen. By processing rates this way, they simplified probabilistic information and shifted their focus to the implications of being at risk and the potential impact of that which might or might not occur. The many uncertainties they faced, the "consequences" of being at risk that parents felt had to be resolved during the decision-making process, fell into 3 major categories: uncertainty that arose because of the ambiguous impact and meaning of having an affected child; uncertainty about how to make a choice and how others would view it, the burden of decision-making; and uncertainty about their ability to fulfill their roles as parents. These issues were perceived as part of the problem to be resolved and were consolidated into "scenarios" in which the parents "tried out the worst." This analysis of counselees' perceptions of the problems created by being at genetic risk suggests that parents may process the disparate facts of their situation in common ways that emphasize their uncertainty, and it indicates that how parents perceive factual information may be more important in orienting their deliberations than what these facts (diagnosis, prognosis, risks) actually are.

Decision Making↗
PubMed1979

Genetic counseling -- the postcounseling period: II. Making reproductive choices.

Qualitative analysis of transcripts of follow-up interviews with 53 parents who had had genetic counseling was undertaken to characterize the process by which childbearing decisions were made and to determine how counselees resolved the problems created by being at risk. Although specific issues to be resolved varied with a parent's perception of his or her situation, all those who considered having subsequent children attempted to limit the uncertainties they faced and to neutralize those consequences perceived as most problematic. To do so, counselees uniformly inferred from factual information and experiences available to them how they could manage the possible consequences of taking a chance. Factors influencing a parent's ability to make a clear decision included the presence of a previous normal child, the diffusion of decision-making responsibility to others, and recognition that one had already managed the worst. When these "facts" could not be processed to provide a sense of coping, parents either decided against reproduction and took appropriate action or made a "non-decision" about reproduction by choosing to leave conception to chance. These various tactics allowed parents to create a "least-lose" option in terms of their child-bearing choices. This analysis of how parents make reproductive decisions, along with previous findings, suggests that being at risk both creates common problems and elicits common responses from counselees. Moreover, it highlights the importance of recognizing parents' perceptions of their situation to understand how their deliberations are structured and how factual information influences their ultimate choices.

Decision Making↗
PubMed1978

Inidcations for prenatal diagnosis in relatives of patients with neural tube defects.

We have reviewed the family histories of children with neural tube defects to determine which relatives are at sufficient risk to be offered amniocentesis for prenatal diagnosis. The recurrence risks for sibs was 6%; therefore, women with one affected child should be made aware of the availability of this test for monitoring subsequent pregnancies. The empiric recurrence risks for various groups of second and third degree relative exceeds 1% only for mothers' sisters' children. The lower values for the other groups may reflect either true biologic differences of reporting biases. Unit the matter is clarified, all sibs of affected children and all sibs of the parents of affected children should be informed of the availability of amniocentesis for monitoring their (or their spouse's) pregnancies.

Amniocentesis↗