Mémoire (M.Sc.)--Université Laval, 1991. / "Mémoire présenté pour l'obtention du grade de maître es sciences (M.Sc.)" Ce mémoire a été réalisé à l'Université du Québec à Chicoutimi dans le cadre du programme de maîtrise en médecine expérimentale (volet génétique), extensionne de l'Université Laval à l'Université du Québec à Chicoutimi. CaQCU CaQCU Document électronique également accessible en format PDF. CaQCU

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Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 36-39).

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Las pruebas de tamizaje prenatal comprenden el asesoramiento preconcepcional, tamizaje materno bioquímico y la ultrasonografía, además de pruebas diagnósticas invasivas como amniocentesis clásica, temprana y con técnica de filtración, la biopsia de vellosidades coriales, biopsia fetal y cordocentesis.El objetivo principal de este estudio fue analizar comparativamente el método de amniofiltración, sus ventajas e inconvenientes en relación con los métodos existentes como la biopsia corial y la amniocentesis precoz sin amniofiltración. Analizando el tiempo necesario para realizar cada procedimiento, los fallos en el cultivo, así como las complicaciones intraprocedimiento y postprocedimiento de cada técnica.En el estudio participaron 921 mujeres candidatas a cariotipo fetal. A 310 pacientes se les realizó biopsia corial, a 302 pacientes amniocentesis precoz con amniofiltración y a 309 pacientes amniocentesis precoz convencional sin amniofiltración. La biopsia corial se realizó a las 11.09 semanas, la amniocentesis precoz con amniofiltración a las 12.48 semanas y la amniocentesis precoz sin amniofiltración a las 12.98 semanas en promedio.Comparativamente, la amniocentesis precoz con amniofiltración requirió mayor tiempo de realización en relación a las otras dos técnicas. De los 921 casos, solo en un 3.4 % se presentaron complicaciones clasificadas como leves moderadas y graves; 9 de ellas en el procedimiento de biopsia corial, 12 durante el procedimiento de amniocentesis precoz con amniofiltración y 11 durante y post procedimiento de amniocentesis precoz sin amniofiltración.Se presentaron 6 casos de fallo de cultivo para cariotipo en la biopsia corial, 2 en la amniocentesis precoz con amniofiltración y 3 en amniocentesis precoz sin amniofiltración.A partir de estos resultados se puede concluir que el método de diagnóstico prenatal amniocentesis precoz con amniofiltración no conlleva ventaja sobre las técnicas de amniocentesis precoz sin amniofiltración y la biopsia corial y que la mayoría de los autores concuerdan en que existen mayores complicaciones cuando estas técnicas se realizan a menor edad gestacional.No existen estudios randomizados para la amniocentesis entre las semanas 13-15 que demuestren claramente la efectividad de la amniocentesis temprana y amniofiltración, por lo que no se debe de considerar como un procedimiento seguro en comparación con la amniocentesis clásica y biopsia de vellosidades coriales, además que en la actualidad existen técnicas como la hibridación in situ con inmunoflourescencia y reacción en cadena de la polimerasa cuantitativa fluorescente, que brindan un diagnóstico citogenético más rápido y seguro de la mayoría de las anormalidades cromosómicas. / Early amniocentesis with amniofiltration in prenatal diagnostic comparative with biopsy of the chorionic villi and early amniocentesis without amniofiltrationThe prenatal screening tests consist of assessment before conception, maternal biochemical screening and a sonogram, in addition to invasive diagnostic tests such as the classical early amniocentesis with a filtration technique, a biopsy of the chorionic villi, a fetal biopsy and chordocentesis.The main objective of this study was to comparatively analyze the amniofiltration method, its advantages and disadvantages in relation to existing methods such as the chorionic biopsy and early amniocentesis without amniofiltration. The time necessary to carry out each procedure was analyzed as well as the problems with the culture and all of the intraprocedural and post-procedural complications of each technique.921 women fetal karyotype candidates participated in the study. A chorionic biopsy was carried out on 310 patients, 302 patients had early amniocentesis with amniofiltration and 309 patients had conventional early amniocentesis without amniofiltration. On the average, chorionic biopsies were performed at 11.09 weeks, early amniocentesis with amniofiltration was performed at 12.48 weeks and early amniocentesis without amniofiltration was performed at 12.98 weeks.Comparatively, the early amniocentesis with amniofiltration required more time to be performed when compared to the other two techniques. Of the 921 cases, only 3.4% had complications classified as slightly moderate to serious, 9 of them occurred with the chorionic biopsy procedure, 12 during the early amniocentesis with amniofiltration procedure and 11 during and after the early amniocentesis without amniofiltration procedure.6 cases of karytype failures of the cultures occurred with the chorionic biopsy, 2 with the early amniocentesis with amniofiltration and 3 with early amniocentesis without amniofiltration.From these results, it can be concluded that the prenatal diagnostic method of early amniocentesis with amniofiltration does not provide any advantage over early amniocentesis techniques without amniofiltration or an advantage over the chorionic biopsy. The majority of authors agree that there are greater complications when these techniques are carried out during earlier stages of gestation.There are no random studies for amniocentesis between weeks 13-15 that clearly demonstrate the effectiveness of early amniocentesis and amniofiltration and for that reason it should not be considered to be a safe procedure when compared with classic amniocentesis and biopsies of chorionic villi. In addition, at present techniques exist such as in situ hybridization with immunofluorescence and a chain reaction of the quantitative fluorescent polymerase that provide faster and safer cytogenic diagnosis of the majority of chromosomal abnormalities.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains iv, 50 p. Includes abstract. Includes bibliographical references (p. 28-30).

Student number: 0200150A MSc (Med) Genetic Counselling - School of Pathology / Increasing numbers of pregnant women of advanced maternal age (AMA) counselled in the prenatal genetic counselling clinics in Johannesburg are human immunodeficiency virus (HIV) positive. This has altered the information these women must consider when deciding about amniocentesis for prenatal diagnosis of chromosomal abnormalities. Antiretroviral treatment (ART) is advised for HIV positive women prior to the procedure, to minimise vertical transmission from mother to child. The risk of mother to child transmission (MTCT) of HIV also necessitates counselling regarding termination of pregnancy (TOP). A study over two 6-month periods in 2003 and 2004 documented the HIV status of the advanced maternal age women attending genetic counselling clinics at three academic hospitals in Johannesburg, and the choices these women made regarding testing for possible chromosome abnormalities. An interview schedule, conducted over 6 months in 2004, investigated the HIV positive women’s perceptions of HIV in pregnancy, and their thoughts on termination of pregnancy based on HIV transmission risk. Of 169 women seen over six months, February to July 2003, 83 (49%) were HIV negative, 15 (9%) were HIV positive and 71 (42%) were of unknown status. Forty (48%) HIV negative patients had amniocenteses compared to 2 (13%) HIV positive women. In 2004, 181 patients were seen; 100 (55%) were HIV negative, 29 (16%) were HIV positive and 52 (29%) were of unknown status. Thirty-nine (39%) HIV negative patients had amniocenteses compared to 4 (14%) HIV positive women. Data from fifteen completed questionnaires indicated that most women understood the severity of HIV infection, 12/15 (80%), five (33%) considered termination of pregnancy based on the HIV transmission risk, and four (27%) would have had amniocentesis if they had been HIV negative. A significant percentage of AMA women attending the genetic counselling clinics are HIV positive, and they are faced with difficult issues, including the risk of chromosome abnormalities in the fetus, the risk of transmission of HIV during pregnancy and amniocentesis, and the option of TOP up to 20 weeks gestation based on the risk of vertical HIV transmission. It is vital that cogent policies are developed to provide optimum care for these women. Ideally, the access to highly active antiretroviral therapy (HAART) throughout pregnancy, to reduce the risk of MTCT of HIV to about 1%, would make the option of prenatal diagnosis a safer one for AMA women to consider.

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A non‐mosaic trisomy 20 was discovered in all cells in two separate cultures from an age‐related genetic amniocentesis. Karyotypes of cells obtained via amniocentésis at the time of termination and of cells cultured from the placenta gave the same unambiguous results. However, the fetus, under macro‐ and microscopic analysis, showed only two minor anomalies: left simian crease and low‐set ears. These findings are more suggestive of a normal or at most mosaic trisomy 20 state. The significance of this finding for prenatal diagnosis is discussed.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 4 uppsatser och 1 appendix.