Intracytoplasmic Sperm Injection
Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh in Male Infertility in Reproductive Medicine, 2019
Specialized sperm-selection methods: Zech selector [41] depends on selecting progressive motile sperm as both nuclear and mitochondrial DNA can be damaged by strand breaks, so the spermatozoa swimming so far have significantly reduced rates of DNA fragmentation. Microfluidic separation [42] is based on a sperm-sorting method with a parallel laminar flow stream to separate motile sperm of good quality. Electrophoretic isolation [43] selection of negatively charged sperm (less DNA damage) helps isolate sperm, which are relatively free of DNA damage, and can be used for ART based on membrane charge. The Zeta method [44] depends on the sperm surface charge. Mature sperm possess an electrical charge of −16 to −20 mV. The electrical charge has been termed ZETA potential (electro kinetic potential) which is the electric potential in the slip plane between the sperm membrane and its surroundings. This method is very simple and entails just holding the sample tube within the gloved hand and turning it three rounds to get the needed charges. With magnetic activated cell sorting (MACS) [45] apoptotic and DNA fragmented sperm have affinity for and so are labeled by annexin V (apoptotic sperm marker) conjugated magnetic spheres. A weak magnetic field separates out those from normal sperm.
Pre-implantation genetic diagnosis
Sheila A.M. McLean, Sarah Elliston in Regulating Pre-Implantation Genetic Diagnosis, 2012
The availability of PGD makes it possible to select embryos based on their sex. While this may be used to avoid the transmission of genetic disease, it could also be used to select embryos purely because of sex, for example for ‘family balancing’. In some families there may be a preponderance of children of one sex, where the parents might wish for a child of the other, and the possibility of sex selection through assisted conception technology is a topic of considerable debate.3233 Whereas the American Society of Reproductive Medicine does not oppose the use of preconception techniques such as sperm sorting to couples ‘who are seeking gender variety in their offspring’,34 neither it nor the American College of Obstetricians and Gynecologists condones the use of PGD for non-medical purposes.3536 Where there is a significant preferential desire for a child or children of one sex – usually male such as in the Middle East,37 China38 and India39 – different rules are generally regarded as necessary to avoid the discrimination that a preference for one sex (usually male) over the other would generate. Although opposition to sex selection for non-medical reasons is not universal,40 it remains impermissible in many jurisdictions and is specifically outlawed by the Human Fertilisation and Embryology Act 2008 in the UK.
Microfluidics in assisted reproduction technology: Towards automation of the in vitro fertilization laboratory
David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham in Textbook of Assisted Reproductive Techniques, 2017
Due to the limitations inherent in a microfluidic sperm sorting device, utilization of the technology must provide some added benefit over conventional processing methods. Conventional sperm preparation methods, such as serial centrifugation, density gradient separation, or swim up, are reported to induce sperm DNA damage, perhaps due to exposure to reaction oxygen species (ROS) (62–64). Preliminary data indicate that sperm isolated using a microfluidic sperm sorting device had significantly lower levels of DNA damage and higher motility compared to those isolated using more conventional approaches (31, 65). Thus, microfluidic sperm sorting may allow for the selection of higher-quality sperm, potentially leading to improved embryo quality.
Microfluidic sperm selection yields higher sperm quality compared to conventional method in ICSI program: A pilot study
Published in Systems Biology in Reproductive Medicine, 2021
Fatemeh Anbari, Mohammad Ali khalili, Abdul Munaf Sultan Ahamed, Esmat Mangoli, Ali Nabi, Fatemeh Dehghanpour, Mojdeh Sabour
Recently, the most rapidly developing field had been the microfluidics-based technologies for sperm preparation and selection. Microfluidic devices have been introduced based on the characteristic of sperm forward movement. Smith and colleagues were first to publish a series of papers demonstrating microfluidics as a viable approach for improving, not only sperm quality, but also laboratory efficiency. They showed that using microfluidics could eliminate the mechanical stress induced on sperm during preparation, such as centrifugation step. Meanwhile, this method can maintain a suitable environment with stable osmolality, temperature and pH (Smith et al. 2012). Thus, microfluidics may help develop new techniques for gamete selection; while, causing minimal damage. This technique provides ability for sperm sorting, insemination and evaluation of sperm and embryo quality in a microenvironment closely resembling the natural conditions in female reproductive system (Samuel et al. 2018). Recently, Quinn and associates compared sperm concentration, progressive motility and DNA fragmentation between DSU and sorting by a microfluidic chip. Their findings demonstrated that spermatozoa processed with these microfluidic chips yielded higher DNA integrity compared with conventional sorting techniques (Quinn et al. 2018). Later, Parrella et al. proposed a microfluidic system as a noninvasive alternative to recover spermatozoa with superior genomic competence for ICSI treatment in men with high DNA fragmentation. Their study proposes a conservative approach to treat couples with recurrent assisted reproductive technology (ART) and implantation failures without resorting to testicular biopsy (Parrella et al. 2019).
Implementing Expanded Prenatal Genetic Testing: Should Parents Have Access to Any and All Fetal Genetic Information?
Published in The American Journal of Bioethics, 2022
Michelle J. Bayefsky, Benjamin E. Berkman
One possible state interest in regulating the scope of prenatal genetic testing would be if unrestricted access to fetal genetic information would cause detrimental population-wide effects. For example, if fetal genetic testing resulted in systematic selection against a particular gender or race and population demographics might shift as a result. Although the state has an interest in protecting the common good, which forms the legal basis of public health interventions such as mandatory vaccination (Jacobson v. Massachusetts 197 U.S. 11 919050), there is little evidence to suggest that ePGT will cause population-level shifts. Data on sex selection, which has long been possible in the United States on the basis of ultrasound findings, show that there may be biases toward male children for third + births among certain immigrant populations (Chinese, Asian Indian and Korean). Even for these minority communities, however, the sex ratios were fairly equal and sex selection only exceeded expected biological variation for child number three or more (Egan et al. 2011). Studies on sex selection associated with assisted reproductive technologies (ART) including preimplantation genetic diagnosis and sperm sorting indicate that many parents want to exercise control over their child’s sex but there is little overall bias for males or females in the US (Dahl et al. 2006; Jain et al. 2005). In general, when people utilize ART to pursue sex selection, it is to achieve “family balancing” (Jain et al. 2005), which could reinforce problematic conceptions of gender but is unlikely to cause the kind of demographic shift that would justify government intervention. ePGT will extend far beyond testing for sex. Given the wide range of possible conditions that can be identified, combined with the low incidence of the kinds of severe conditions for which most parents would consider termination (Sullivan et al. 2019), it is very unlikely that ePGT would result in detrimental population-wide effects. However, it is possible that in cultural contexts outside the United States, population-wide shifts with ePGT could be more significant.
Related Knowledge Centers
- Artificial Insemination
- Egg Cell
- Sperm
- X Chromosome
- Y Chromosome
- In Vitro Fertilisation
- Flow Cytometry
- Fertilisation
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- Sperm Washing