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Fertilization and normal embryonic and early fetal development
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Asim Kurjak, Ritsuko K. Pooh, Aida Salihagic-Kadic, Iva Lausin, Lara Spalldi-Barisic
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.
Ultrasonic Monitoring of Follicular Growth and Ovulation in Spontaneous and Stimulated Cycles
Published in Asim Kurjak, Ultrasound and Infertility, 2020
The most important changes in the preovulatory follicle include the shift of steroidogenesis in granulosa cells from estrogen to progesterone, luteinization of granulosa cells, and initiation of the final oocyte maturation. This is accompanied by dissociation of the cumulus oophorus and separation of granulosa and theca layers.22 Some of these features can be recognized by ultrasound.
Empirical In Vitro Fertilization for Recurrent Pregnancy Loss: Is It a Valid Concept?
Published in Howard J.A. Carp, Recurrent Pregnancy Loss, 2020
Michal Kirshenbaum, Raoul Orvieto
Physiological intracytoplasmic sperm injection (PICSI) utilizes the presence of hyaluronic acid (HA) binding sites on the sperm plasma membrane. HA binding sites indicate sperm maturity and ability to attach the extracellular matrix of the cumulus oophorus. A recent Cochrane review aiming to evaluate the impact of advanced sperm selection techniques on ART outcomes could not find sufficient evidence to allow the review authors to determine whether sperm selected by surface charge, sperm apoptosis, or HA binding have any additive value over conventional selection [17]. No difference was found between the methods in terms of live births, clinical pregnancy, or miscarriage rates. However, this meta-analysis was not restricted to RPL patients.
Application of ultrasound markers measured at different time points of COH cycle in the prediction of ovarian response for individualised ovulation induction
Published in Journal of Obstetrics and Gynaecology, 2022
Yue-Wei Li, Xiao-Wen Liang, Jing-Hui Fang, Zhi-Yi Chen
The growth of cumulus cells is closely related to the development of the oocyte, and cumulus cell apoptosis affects the maturation, fertilisation, and cleavage of the oocyte and may thus be used to predict IVF outcomes. With the advancement of high-resolution TV-CDS, ultrasound features can be regarded as markers in the evaluation of ovarian response. Moreover, TV-CDS is more likely to detect the cumulus on the day of hCG injection, thus indirectly indicating a good ovarian response, which is correlated with the number of retrieved oocytes, fertilised eggs, and excellent-grade embryos (Jadaon et al. 2012). In this study, we found that the number of cumulus oophorus observed on the day of hCG injection was positively correlated with the number of oocytes and fertilised oocytes. The number of cumulus oophorus gradually increased from the low response group to the normal response group and the high response group, and the number of oocytes retrieved, the number of fertilised oocytes, and the number of high-quality embryos also gradually increased. These results indirectly prove that the cumulus oophorus is a syncytium with complete structure and function, which is closely related to the growth, development, maturation, and fertilisation of oocytes (Tola et al. 2019). According to Bertolin's study, successful fertilisation is related to the quantity and quality of cumulus expansion. The cumulus oophorus creates a beneficial microenvironment for the growth and development of oocytes (Bertolin et al. 2017). The cumulus oophorus is essential for normal oocyte development, ovulation, and fertilisation.
Thymoquinone ameliorates obesity-induced metabolic dysfunction, improves reproductive efficiency exhibiting a dose-organ relationship
Published in Systems Biology in Reproductive Medicine, 2019
Seba Harphoush, Guoqing Wu, Gao Qiuli, Margaret Zaitoun, Maissam Ghanem, Yonghui Shi, Guowei Le
The left ovary in three non-reproductive females each group and a part of left mammary gland in six lactating females each group was fixed in Paraformaldehyde 4% in PBS for 24 h and embedded in paraffin. Hematoxylin and Eosin (HE) staining was performed on 5 mm serial to analyze the histopathological changes of ovarian follicle cells and mammary alveolar lumens. HE sections were observed with a CX31 RTSF microscope (Olympus Corporation, Tokyo, Japan). In lactating mammary glands, alveolar Lumens area was measured using Image-J NIH software (McGinley and Thompson 2011). In non-reproductive females’ ovaries, follicular stages were classified to early stage follicles (primary follicles; secondary follicles; antral follicles) and later stage follicles (Graafian follicles; corpus luteum) according to the Erickson’s classification (Williams and Erickson 2012). Graafian follicle: the oocyte is surrounded by cumulus oophorus cells, and is adjacent to a single large antrum (an ovum develops prior to ovulation). Corpus luteum: It is the remains of the ovarian follicle that has released a mature ovum during a previous ovulation. Only later stage follicles were observed and counted per one ovary to estimate ovulation.
Telomeres as a molecular marker of male infertility
Published in Human Fertility, 2019
Ewa Boniewska-Bernacka, Anna Pańczyszyn, Natalia Cybulska
Infertility resulting from male factors is a growing social problem that requires understanding many cellular and molecular mechanisms. Therefore, evaluation of the sperm’s ability to properly fertilize an egg should be the main objective of semen analysis. To accomplish this multistage process, spermatozoa must undergo capacitation and the acrosome reaction, so that mutual recognition and fusion of gametes are possible. This process involves: (i) penetration through the cumulus oophorus cell layer; (ii) penetration of the zona pellucida; (iii) fusion of the spermatozoon plasma membrane with oolemma, activation of the dormant egg cell; (iv) spermatozoon chromatin decondensation; (v) male pronucleus formation; and (vi) fusion with the female pronucleus in the final stage. The male infertility factor for a given couple may be related to a disorder at each of the above stages, and the underlying cause cannot be identified in 30–40% of men (Jungwirth et al., 2015; Reig-Viader et al., 2014).