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Genomic technologies
Published in Wendy A. Rogers, Jackie Leach Scully, Stacy M. Carter, Vikki A. Entwistle, Catherine Mills, The Routledge Handbook of Feminist Bioethics, 2022
Genomic screening and testing programs can be used at several stages of human life. At the earliest stages, they can be used before embryo implantation in combination with reproductive technologies such as in vitro fertilization (IVF) (De Rycke et al. 2020). IVF is the most common reproductive technology. It involves several steps, including ovarian stimulation to produce multiple eggs, retrieval of the eggs from the woman’s body, mixing them with sperm to create embryos, and transferring of the embryos into the woman’s body. Before embryos are transferred, genomic screening and testing techniques are employed to identify, and usually discard, embryos that carry genomic variants associated with particular diseases or disorders, with the aim of increasing the chances of giving birth to children without the disease or disorder in question. Fertility clinics also use genomic technologies to detect embryos with aneuploidy (an abnormal number of chromosomes in a cell), in order to select unaffected embryos for transfer so as to enhance pregnancy rates.
Clinical Endocrinology of Pregnant Mares
Published in Juan Carlos Gardón, Katy Satué, Biotechnologies Applied to Animal Reproduction, 2020
Embryo implantation begins around day 36 postovulation and involves the development of the chorionic band from the trophoblast, whose cells invade the maternal endometrium giving rise to endometrial cups. The development of the invasive trophoblast requires the proliferation and differentiation of the uninuclear cells of the trophoblast into the binuclear cells that will later synthesize the equine chorionic gonadotropin (eCG). It also acquires an invasive character that allows them to penetrate the endometrial luminal epithelium (Antczak et al., 2013). In relation to this last fact, it has been postulated the implication of several growth factors such as the epidermal growth factor (EGF) and the transforming growth factor type β (TGFβ), whose expression in the glandular epithelium increases notably around the 30–40 of gestation (Lennard et al., 1995, 1998). Likewise, VEGF and its receptors are found in the luminal epithelium and glandular endometrium during the development of the chorionic band. This may autocrine stimulate the maturation of the chorionic band cells (Allen et al., 2007). Similarly, hepatocyte growth factor or “scatter factor” is expressed in the mesothelial and mesenchymal allantoid cells underlying the chorion and chorionic band, suggesting that it may act as a mitogenic agent during trophoblastic proliferation (Gerstenberg et al., 1999).
Fibroids and Endometrial Receptivity/Embryo Implantation
Published in Botros R.M.B. Rizk, Yakoub Khalaf, Mostafa A. Borahay, Fibroids and Reproduction, 2020
Kamaria C. Cayton Vaught, Maria Facadio Antero, Jacqueline Y. Maher, Chantel I. Cross
The process of embryo implantation is necessary for the establishment of a pregnancy. It involves embryo apposition, adhesion, and invasion into a receptive endometrium (Figure 3.1). In order for implantation to occur and a pregnancy to be established, embryo viability and endometrial receptivity need to be in synchrony, which normally occurs due to complex communication between both the embryo and the endometrium.
Repeated application of luteal phase oestradiol/GnRH antagonist priming increases IVF success for poor ovarian reserve patients
Published in Journal of Obstetrics and Gynaecology, 2023
Temel Ceyhan, Mustafa Ozturk, Ummu Gul Yıldız, Ulas Fidan, Elif Agacayak, Mustafa Ulubay, Cem Korkmaz
There is no standard treatment protocol applied to patients with low ovarian reserve. In this patient group, the rate of lack of response to stimulation and cycle cancellation is high. In this study, we compared the results of second cycle LPP application in patients with low ovarian reserve who resulted in failed IVF after commonly used LPP, microdose flare up protocol and antagonist protocols. b-hCG positivity and clinical pregnancy rate were found to be significantly higher in the LPP + LPP group. There was no significant difference between the two groups in terms of live birth rate. No significant difference was observed between the groups in terms of the number of oocytes collected, metaphase II oocyte count, number of embryos obtained, embryo quality and number of transferred embryos. Similarly, an increase in the number of oocytes collected was not shown with LPA when compared to MD in the study performed by Ata et al. (2011). However, a tendency towards higher embryo implantation and clinical pregnancy rates has been observed, but the differences are not statistically significant (Ata et al.2011).
Toxicological effects of the Morinda citrifolia L. fruit extract on maternal reproduction and fetal development in rats
Published in Drug and Chemical Toxicology, 2023
Thaís Leal-Silva, Maysa Rocha Souza, Larissa Lopes Cruz, Rafaianne Queiroz Moraes-Souza, Verônyca Gonçalves Paula, Thaigra Sousa Soares, Vanessa Dela Justina, Fernanda Regina Giachini, Débora Cristina Damasceno, Madileine Francely Américo, Gustavo Tadeu Volpato
For successful pregnancy, highly organized physiological and molecular processes must occur during implantation. Our results indicate that the use of M. citrifolia can potentially influence and impair the embryo implantation process in rats. The embryonic implantation number is related to the number of corpora lutea, which is an indicator of successful blastocyst implantation in the endometrium until day 4 or 5 of pregnancy in rodents (Fonseca et al. 2012). In rodents, the implantation period is limited, and blastocysts need to interact adequately with the maternal receptive endometrium. If this process does not occur in an orderly manner, embryo implantation may fail or be defective; in the latter case, adverse effects may occur during pregnancy (Cha et al. 2012). In the present study, an increased percentage of embryonic loss before implantation was observed in the group treated with the highest dose of the plant extract. Müller et al. (2009) verified a reduction in uterine contraction induced by arachidonic acid, and related it to the anti-estrogenic activity of M. citrifolia, contributing to a disturbed implantation process. Su et al. (2002) demonstrated the selective inhibitory activity of M. citrifolia on cyclooxygenase-2 (COX-2) expression. COX-2 plays important roles in reproduction and is responsible for producing prostaglandins, which affect the endometrial vascular permeability during implantation (Salleh 2014).
Developing a Reflexive, Anticipatory, and Deliberative Approach to Unanticipated Discoveries: Ethical Lessons from iBlastoids
Published in The American Journal of Bioethics, 2022
Rachel A. Ankeny, Megan J. Munsie, Joan Leach
Study of early human development is essential for continued understanding of pregnancy including effects of environmental toxins and gene mutations on development, and for studying fertility problems and refining assisted reproductive technologies. Although difficult to measure and hotly debated, recent estimates indicate that for women of reproductive age, losses between embryo implantation and clinical recognition of pregnancy are approximately 10–25%; although considerably lower than older estimates which ranged from 30–70%, this rate is still non-trivial (Jarvis 2016). But research on these developmental stages has been accompanied by considerable challenges in many locales related to ethical, social, and legal constraints on the availability of human embryos for research purposes. Hence developing in vitro models of human development (particularly three-dimensional [3-D] models that are scalable and versatile) has been a priority amongst developmental biology researchers.