Size Of Follicle and Oocyte Maturation Status in an Assisted Reproductive Technology Programme

2012 ◽  
Vol 1 (3) ◽  
2020 ◽  
Vol 103 (6) ◽  
pp. 1157-1170
Author(s):  
Michael J D’Occhio ◽  
Giuseppe Campanile ◽  
Pietro S Baruselli

Abstract Kisspeptin (KISS1) is encoded by the KISS1 gene and was initially found to be a repressor of metastasis. Natural mutations in the KISS1 receptor gene (KISS1R) were subsequently shown to be associated with idiopathic hypothalamic hypogonadism and impaired puberty. This led to interest in the role of KISS1 in reproduction. It was established that KISS1 had a fundamental role in the control of gonadotropin releasing hormone (GnRH) secretion. KISS1 neurons have receptors for leptin and estrogen receptor α (ERα), which places KISS1 at the gateway of metabolic (leptin) and gonadal (ERα) regulation of GnRH secretion. More recently, KISS1 has been shown to act at peripheral reproductive tissues. KISS1 and KISS1R genes are expressed in follicles (granulosa, theca, oocyte), trophoblast, and uterus. KISS1 and KISS1R proteins are found in the same tissues. KISS1 appears to have autocrine and paracrine actions in follicle and oocyte maturation, trophoblast development, and implantation and placentation. In some studies, KISS1 was beneficial to in vitro oocyte maturation and blastocyst development. The next phase of KISS1 research will explore potential benefits on embryo survival and pregnancy. This will likely involve longer-term KISS1 treatments during proestrus, early embryo development, trophoblast attachment, and implantation and pregnancy. A deeper understanding of the direct action of KISS1 at reproductive tissues could help to achieve the next step change in embryo survival and improvement in the efficiency of assisted reproductive technology.


2019 ◽  
Vol 167 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Osamu Udagawa ◽  
Naotada Ishihara

Abstract Mitochondria play many critical roles in cells, not only by supplying energy, but also by supplying metabolites, buffering Ca2+ levels and regulating apoptosis. During oocyte maturation and subsequent embryo development, mitochondria change their morphology by membrane fusion and fission, and coordinately undergo multiple cellular events with the endoplasmic reticulum (ER) closely apposed. Mitochondrial fusion and fission, known as mitochondrial dynamics, are regulated by family members of dynamin GTPases. Oocytes in animal models with these regulators artificially altered exhibit morphological abnormalities in nearby mitochondria and at the ER interface that are reminiscent of major cytoplasmic dysmorphisms in human assisted reproductive technology, in which a portion of mature oocytes retrieved from patients contain cytoplasmic dysmorphisms associated with mitochondria and ER abnormal morphologies. Understanding organelle morpho-homeostasis in oocytes obtained from animal models will contribute to the development of novel methods for determining oocyte health and for how to deal with dysmorphic oocytes.


2001 ◽  
Vol 13 (1) ◽  
pp. 95 ◽  
Author(s):  
Lyndon Hale

A review of current literature (1990–2000) was undertaken to identify factors that are important in the correct placement of embryos in utero. Although there are no absolute prerequisites, ultrasound monitoring to ensure correct catheter placement, pretreatment assessment of the cervical canal, minimization of trauma, avoidance of mucus and the use of a ‘soft’ catheter are all considered important factors in this process. Early patient mobilization after the transfer procedure has not been shown to influence the outcome. The establishment of a benchmark against which to evaluate individual performance and participation in ‘refresher courses’ if indicated will help to maximize the implantation rates of the assisted reproductive technology programme as a whole.


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