Is the Human Embryo an Organism?
Nicholas Colgrove, Bruce P. Blackshaw, Daniel Rodger in Agency, Pregnancy and Persons, 2023
Early human development is summarized in Figure 1.1. Briefly, upon sperm-egg fusion at fertilization, a single cell (the zygote) is formed (Figure 1.1A). The zygote divides rapidly, producing a number of smaller cells known as blastomeres (Figure 1.1B). By the second or third day following sperm-egg fusion, the blastomeres have formed a ball-like structure known as a morula-stage embryo (Figure 1.1C). Cell division continues, and by the fifth day, the embryo has grown to about one hundred cells and formed a fluid-filled structure known as a blastocyst (Figure 1.1E). At this stage, the first two committed cell types have arisen. The cells that make up the outer layer of the blastocyst are known as trophectoderm (TE). Inside the blastocyst is a cluster of cells, known as the inner cell mass (ICM).
Fertilization and normal embryonic and early fetal development
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Already few minutes after the ovulation, oocyte is located in the ampullar part of the fallopian tube. It is surrounded by the zona pellucida. On the surface of the zona pellucida, there are few rows of the granulosa cells that make corona radiata. At the periphery of the corona radiata are left cells of cumulus oophorus. Often, these three units are called oocyte–corona–cumulus complex. Capability for the fertilization is limited: oocyte can be fertilized only 6 to 12 hours after the ovulation. Sperms are capable for fertilization 48 to 72 hours, until they are movable. Fertilization occurs in the ampullar part of the fallopian tube. The process of fertilization begins with conditioning of the spermatozoon in the male and female reproductive tracts. Thereafter, fertilization involves not only the egg itself but also the various investments that surround the egg at the time it is released from the ovary follicle. Fertilization, therefore, is not an event; it is a complex biochemical process requiring a minimum of 24 hours to complete syngamy (formation of a diploid set of chromosomes). During that process, there is no commingling of maternal and paternal chromosomes within a single nuclear membrane (pre-zygote); after this process, the paternal chromosome material is commingled (zygote). The most important activity of this new cell is the recognition of the new genome that presents the principal information center for the development of the human being and for all its further activities.
Introduction
Rosa Maria Quatraro, Pietro Grussu in Handbook of Perinatal Clinical Psychology, 2020
The second part, which covers procreation, pregnancy and delivery, focuses instead on the adverse events that can lead to risk factors for perinatal emotional disorders, whether simultaneously with an established or interrupted pregnancy or during subsequent pregnancies and postpartum periods. The chapters of this second part unfold from a starting point of the clinical reality of those who work with women daily and who find themselves dealing with ever more complex maternity situations. Increased maternal and paternal age, environmental pollutants and stress have led to a reduction in fertility which is increasingly being overcome by homologous- and heterologous-assisted fertilization, as well as by biotechnology. All of this, though, has personal and social costs that can only be partially foreseen and that give us cause to reflect, as put forward by Joan Raphael-Leff. The costs, however, are also emotional. These women and couples are in fact often bearers of intense suffering that is little expressed and shared, and which needs to be seen, accepted and listened to by society, by doctors and by healthcare workers so that the women and the couples themselves can take charge of it. This option, as Tewes Wischmann explains in Chapter 4, also has a preventive value with respect to perinatal emotional health and to the parent-child relationship.
Resilience among involuntarily childless couples and individuals undergoing infertility treatment: a systematic review
Published in Human Fertility, 2023
Neda Haseeb Khan, Mohammad Ghazi Shahnawaz, Ansha Patel, Poonam Kashyap, Chandra Bhushan Singh
Four major databases (PubMed, Scopus, ScienceDirect, and Wiley Online Library) were searched with no predetermined year of published research. Two groups of keywords were utilized as search terms:1) resilience and 2) infertility, assisted reproductive technology, IVF, and in-vitro fertilization. The search terms within two groups were combined by using ‘AND’ and within a group were combined using ‘OR’. A total of 4101 articles were retrieved from these databases, 157 were from PubMed, 253 were from Scopus, 3560 were from ScienceDirect and 131 were from Wiley Online Library. These articles were downloaded on EndNote and duplicate articles were immediately identified and removed. Since no restrictions were set initially in the database, therefore, studies from various other subject fields i.e. biomedical, medical, genetics, etc. also got included.
Exploring Cisgender Women’s Experiences of Reproductive Loss After In Vitro Fertilization
Published in Women's Reproductive Health, 2023
Meghan Forgie, Amanda Vandyk, Wendy Peterson, Danielle Dubois
Infertility is the inability to conceive despite frequent, unprotected sex over the span of one year (Zegers-Hochschild et al., 2009). Globally, approximately 48 million couples live with infertility (Mascarenhas et al., 2012; World Health Organization, 2021). In some countries, such as Canada, infertility has doubled in the last four decades (Public Health Agency of Canada, 2019). In vitro fertilization—the process of external fertilization of the egg with sperm and the subsequent embryo transfer into the uterus (Zegers-Hochschild et al., 2009)—is a treatment option for infertility. Unfortunately, nearly 70% of people who undergo in vitro fertilization experience an unsuccessful attempt or treatment failure, and approximately 20% of pregnancies achieved through in vitro fertilization, using one’s own oocytes, result in miscarriage (Canadian Fertility & Andrology Society, 2019). Reproductive losses, such as treatment failure and miscarriage following the use of assisted reproductive technologies, can lead to stress disorders and increased levels of anxiety (Farren et al., 2016), problems within the partner relationship (Gold et al., 2010; Luk & Loke, 2019; Shreffler et al., 2012), as well as sadness and mourning (Brier, 2008; Fenstermacher & Hupcey 2013; Gameiro & Finnigan, 2017). Research has also shown that the use of in vitro fertilization itself has physical, psychological, emotional, and financial consequences (Boivin et al., 2012).
Sildenafil aggravates adriamycin-induced testicular toxicity in rats; a preliminary investigation
Published in Drug and Chemical Toxicology, 2023
Anne A. Adeyanju, Omolola R. Oyenihi, Oluwafemi O. Oguntibeju, Oreoluwa Ojomu
The cells of the reproductive system are one of the cells most affected by ADR treatment due to the rapidly proliferating characteristic of these cells similar to tumor cells (Prieto-Callejero et al.2020). Studies have reported the induction of testicular toxicity in rats by the intraperitoneal injection of a single dose of ADR (20 mg/kg) (Saalu et al.2010, Molehin et al.2018). The manifestation of testicular toxicity was assessed via analysis of sperm function: sperm count, motility, sperm viability, and morphological abnormalities (Hukkanen et al.2016). Evidence from previous studies indicates that sperm motility is an important factor in the success of fertilization, and any negative impact of motility would cause adverse effects on the fertilization capacity (Kumar and Singh 2015, Peiris et al.2015). ADR induced testicular toxicity in rats evident by a significant reduction in sperm count (99.40 ± 16.12 × 106/ml in ADR-treated rats versus 135 ± 13.52 × 106/ml in the vehicle control) and sperm motility (70 ± 7.07% in ADR-treated rats versus 85 ± 7.07% in the vehicle control) indicating a negative effect on reproductive health.
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