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Embryo Cell-Free DNA in the Culture Medium and Its Potential for Non-Invasive Aneuploidy Testing
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Carmen Rubio, Luis Navarro-Sánchez, Carmen M. García-Pascual
Despite the promise of this non-invasive technology, several questions remain: 1) Can different embryo culture protocols be applied? 2) How long should the medium be in contact with the embryo before it is collected? 3) Are assisted hatching (AH) or previous vitrification needed to obtain sufficient cfDNA? 4) Is the amount of cfDNA collected influenced by the embryo quality? 5) How can contamination from cumulus cells be minimized? 6) Do the amplification methods, sequencing platforms, or bioinformatics analyses used impact the results? And the core question: can cfDNA from SBM be reliably used for aneuploidy testing in human blastocysts? In this chapter, we review the studies published in this field so far and discuss our own research.
Use of Blastocyst Culture
Published in Botros Rizk, Yakoub Khalaf, Controversies in Assisted Reproduction, 2020
Mohamed A. Aboulghar, Mona M. Aboulghar
A Cochrane review (24) included 32 studies: 17 studies of randomized women (total 3666), 3 randomized cycles (total 1018), and 12 randomized oocytes (over 15,230). It was not possible to pool any of the data because each study compared different culture media. Only seven studies reported live birth or ongoing pregnancy. Four of these studies found no evidence of a difference between the media compared, for either day 3 or day 5 embryo transfer. Most studies (22/32) failed to report their source of funding, and none described their methodology in adequate detail. The overall quality of the evidence was rated as very low for nearly all comparisons. The authors’ conclusions were that an optimal embryo culture medium is important for embryonic development and, subsequently, the success of IVF or ICSI treatment. There has been much controversy about the most appropriate embryo culture medium. Numerous studies have been performed, but no two studies compared the same culture media, and none of them found any evidence of a difference between the culture media used. We conclude that there is insufficient evidence to support or refute the use of any specific culture medium. Properly designed and executed randomized trials are necessary.
Intracytoplasmic Sperm Injection
Published in Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh, Male Infertility in Reproductive Medicine, 2019
Emad Fakhry, Medhat Amer, Botros Rizk
Embryo culture: After oocyte injection, the oocytes are cultured in embryo culture media (single step or sequential culture). The single-step media was developed for zygote development to the blastocyst stage. Prior to compaction, human embryos require pyruvate and nonessential amino acids for nutrition. They subsequently use essential amino acids and glucose. Several factors affect the embryo culture system including pH, gas concentration in the incubator (CO2 and O2), temperature, frequency of opening the incubator, culture media droplet size, protein supplement, single or group culture, and the presence of ROS [31].
Ethics Considerations Regarding Artificial Womb Technology for the Fetonate
Published in The American Journal of Bioethics, 2023
Felix R. De Bie, Sarah D. Kim, Sourav K. Bose, Pamela Nathanson, Emily A. Partridge, Alan W. Flake, Chris Feudtner
Fertilization of a human egg outside of the maternal body and subsequent successful implantation was first performed in 1978 in the United Kingdom, resulting in the birth of the famous “test tube baby” Louise Brown (Steptoe and Edwards 1978). In vitro fertilization (IVF) since then has become the cornerstone of assisted reproductive technologies, which in the United States in 2018 was involved in 1.9% of births according to data available from the Centers for Disease Control and Prevention (CDC 2018). Upon fertilization, the zygote is typically cultured for three to five days before it is implanted in the womb to become an embryo. In an experimental setting however, continued research efforts have led to optimization of culture conditions allowing human embryo culture until 14days conceptional age (CA)(Deglincerti et al. 2016; Shahbazi et al. 2016). In most jurisdictions, legal restrictions prohibit the culture of human embryos beyond 14days of development (Pera 2017). Although the authors of this experimental work invoke these legal reasons for not going beyond the two-week hallmark, their work and findings have been used to advocate for an extension of these legal and moral limitations (Morris 2017). In 2021, the International Society for Stem Cell Research (ISSCR) updated their guidelines, recommending that studies proposing to grow human embryos beyond the two-week mark be considered on a case-by-case basis, and be subjected to several phases of review to determine at what point the experiments must be stopped (ISCCR 2021; Subbaraman 2021).
In vitro study of the toxic and teratogenic effects of prednisolone, azathioprine and mycophenolate mofetile on embryological development of rats
Published in Drug and Chemical Toxicology, 2022
Zeliha Fazliogullari, Ahmet Kagan Karabulut, Nadire Unver Dogan, Ismihan Ilknur Uysal, Hasan Acar
Teratogenic agents can cause abnormal embryogenesis in developing cells and tissues through special mechanisms. Teratogenic effects of the agents are mostly determined after the changes they cause in apoptosis, biosynthesis and morphogenesis (Bailey 2005). After the probable toxic and teratogenic effects of the drugs used in our study were evaluated by using the embryo cultivation technique, the effects on apoptosis of these drugs were evaluated through use of the TUNEL assay. PRZ was detected to cause apoptosis beginning at the minimum toxic dose (30 µg/ml), while the other drugs caused the same effect beginning at the lower doses (AZ: 3 µg/ml, MMF: 1 µg/ml). In literature review, no in vitro embryo culture studies on the effects of these drugs on apoptosis were found. Only the major abnormalities can be detected through evaluation system of embryological growth and development using the in vitro embryo culture technique. Apoptosis is a chain of events occurring at the cellular level. AZ and MMF used in this study are the drugs which directly affect the DNA and RNA synthesis by inhibiting the purine and pyrimidine syntheses. Therefore, these effects could not be detected using the morphological system while a high ratio of apoptosis was identified at the cellular level.
Proteomics based drug repositioning applied to improve in vitro fertilization implantation: an artificial intelligence model
Published in Systems Biology in Reproductive Medicine, 2021
Roberto Matorras, Raquel Valls, Mikel Azkargorta, Jorge Burgos, Aintzane Rabanal, Felix Elortza, Jose Manuel Mas, Teresa Sardon
Polaprezinc also leads to higher expression of numerous growth factors that participate in uterine receptivity and vascular hyperpermeability necessary for blastocyst implantation. One of the key players among those is vascular endothelial growth factor (VEGF), an angiogenic factor known to be essential for endometrial repair (Chen et al. 2015). The corresponding receptors are expressed at peri-implantation stages and mediate vascular hyperpermeability necessary for blastocyst implantation (Torry et al. 2007). It has been argued that VEGF levels are tightly regulated in the decidua, and disruption of this balance could lead to implantation failure (Torry et al. 2007). In addition, it has been proposed as a useful addition to embryo culture medium (Streiter et al. 2016). This is a very interesting candidate with various concomitant benefits on EI and high predictive value for both the condition (70.99%) and the key points of intervention (69.28%). However, the use of the drug to prevent implantation failure has not been reported.