ABSTRACT
In vitro fertilization (IVF) is the most successful and efficient approach to infertility treatment. Choosing the appropriate embryos for transfer significantly decreases the pregnancy failure rate and improves IVF results. Invasive procedure to acquire embryo DNA has a significant limitation. The differences of metabolites, nucleic acids, proteins and other components in embryo medium can help to screen embryos with potential development to improve implantation rate and pregnancy rate, reduce abortion rate and avoid the transfer of aneuploid embryos and the transmission of mutated genes to offspring. The metabolomics screening of high developmental potential embryos with embryo culture medium can assess the developmental potential of embryos comprehensively, objectively and noninvasiveness, which is crucial for improving the pregnancy rate of single embryo transfer.
ABSTRACT
From patients with a poor prognosis of pregnancy, 1620 embryos generated in vitro and chromosomal analysis was performed on these embryos. The result was yielded in 1596 embryos, out of them 536(34%) were euploid and 1060(66%) carried chromosomal abnormalities. In addition, 92% of embryos with multinucleated cells were diagnosed mosaics whereas the 86% of chromosomal abnormalities were associated to the presence of cytoplasmic concentration. For the derivation of the normal embryonic stem cell (ESC)lines and developmental modelling aneuploid embryos have been used. Genetic diagnosis at the cleavage or blastocyst stage could be partly abnormal because during the preimplantation diploid- aneuploid mosaic embryos was most frequently observed. From a single cell of a particular embryo the chromosomal status of that embryo can be determined, thus the prevalence of mosaicism. Detection of aneuploidy in single cells have been developed recently. After conducting research methods, it was confirmed that aneuploidy is a common feature of human oocytes and preimplantation embryos. The detection of segmental aneuploidy is currently considered problematic for embryo diagnosis and patient counselling, so the data are of great relevance for preimplantation genetic testing. The first major milestone in early mammalian embryogenesis was the formation of a totipotence blastocyst which is capable of implantation. The whole chromosomal abnormalities, or aneuploidy, determines whether the human embryos will arrest or reach the blastocyst stage. Certain embryos can still form blastocyst depending on the type of chromosomal abnormalities and that can be morphologically indistinguishable from chromosomally normal embryos.
ABSTRACT
El juicio ético se realiza mediante la integración interdisciplinar del sentido natural de los procesos biológicos con su significado humano. Las Técnicas de Reproducción Asistida son paradigmáticas de una experimentación que no cumple los requisitos científicos ni éticos. La biología de la fecundación ha sido pasto de ficciones al no reconocer los límites naturales. Sobre esa pseudo-biología, la bioética ha sufrido la embestida de la ideología del hombre autónomo, que se arroga reinventar al hombre y dirigir el progreso con base en poder tecnológico. La ética de la bioética exige una nueva reflexión que parta de una ciencia libre de prejuicios.
Ethical judgment is made by the interdisciplinary integration of the natural sense of the biological processes and its human meaning. Assisted reproduction techniques are a paradigm of experiments that do not fulfill both the scientific and the ethical requirements. Fecundation biology has been a subject of frictions as it has not recognized the natural boundaries. On that pseudo-biology, bioethics has suffered the attack of the autonomous man's ideology, which claims that it re-invents the concept of mankind and manages progress, based on technological power. The ethics of bioethics demands a new reflection based on a prejudice-free science.
O juízo ético se realiza mediante a integração interdisciplinar do sentido natural dos processos biológicos com seu significado humano. As Técnicas de Reprodução Assistida são paradigmáticas de uma experimentação que não cumpre os requisitos científicos nem éticos. A biologia da fecundação foi pasto de ficções ao não reconhecer os limites naturais. Sobre essa pseudobiologia, a bioética sofreu a investida da ideologia do homem autônomo, que se arroga reinventar ao homem e dirigir o progresso com base em poder tecnológico. A ética da bioética exige uma nova reflexão que parta de uma ciência cesses and its human meaning. Assisted reproduclivre de preconceitos.
ABSTRACT
OBJECTIVE: The majority of embryo transfers (ETs) to date have been performed on day 3 to reduce the potential risk of developmental arrest of in vitro cultured embryos before ET. Development of sequential media has significantly improved culture conditions and allowed blastocyst transfer on day 5. While day 5 ET provides higher clinical pregnancy outcomes with reduced risks of multiple pregnancies, it still has potential risks of developmental arrest of IVF embryos. The aim of this study was to evaluate the clinical outcomes of day 4 ETs and compare the efficacy of day 4 ET with day 5 ET. METHODS: From 2006 to 2009, a total of 747 fresh IVF-ET cycles were retrospectively analyzed (day 4, n=440 or and day 5, n=307). The cycles with any genetic factors were excluded. The rates of matured oocytes, fertilization, good embryos, and clinical pregnancy of the two groups were compared. The chi-square test and t-test were used for statistical analysis. RESULTS: There were no significant differences between the two groups with respect to the mean age of the females and rates of matured oocytes. The pregnancy outcomes of day 4 ET (40.7%) were similar to those of day 5 ET (44.6%). The implantation rate of day 5 ET (24.2%) was significantly higher than that of day 4 ET (18.4%) (p=0.003). CONCLUSION: Day 4 ET can be chosen to avoid ET cancellation in day 5 ET resulting from suboptimal circumstances in the IVF laboratory, but the decremented quality of embryos for transfer and the decreased pregnancy rate must be taken into consideration.
Subject(s)
Female , Humans , Pregnancy , Blastocyst , Embryo Transfer , Embryonic Structures , Fertilization , Oocytes , Pregnancy Outcome , Pregnancy Rate , Pregnancy, Multiple , Retrospective StudiesABSTRACT
El diagnóstico genético preimplantacional (DGP) es el estudio de alteraciones cromosómicas y genéticas en el embrión, antes de su transferencia a la madre. Permite conocer aquellos embriones libres de anomalías cromosómicas o mutaciones genéticas. En esta revisión se describe la experiencia de un centro de reproducción asistida en Perú, realizando diagnóstico genético preimplantacional a embriones en día 3 de desarrollo. Se muestra resultados de cinco años, con 711 ciclos. El diagnóstico genético preimplantacional sería una herramienta eficaz para seleccionar los embriones con mayor potencial de implantación, que puedan dar origen a un nacido vivo sano.
Preimplantation genetic diagnosis (PGD) is the study of chromosomal or genetic alterations in the human embryo before transfer to the mother. It determines those embryos free of chromosomal abnormalities or genetic mutations. This review describes the 5-year experience including 711 cycles of an assisted reproduction center in Peru, performing PGD to embryos on day 3 of development. Preimplantation genetic diagnosis would be an effective tool to select embryos with higher implantation potential, which may lead to a healthy live birth.