scholarly journals Superovulation Does Not Alter Calcium Oscillations Following Fertilization

Author(s):  
Virginia Savy ◽  
Paula Stein ◽  
Min Shi ◽  
Carmen J. Williams

Superovulation is a common approach to maximize the number of eggs available for either clinical assisted reproductive technologies or experimental animal studies. This procedure provides supraphysiological amounts of gonadotropins to promote continued growth and maturation of ovarian follicles that otherwise would undergo atresia. There is evidence in mice, cows, sheep, and humans that superovulation has a detrimental impact on the quality of the resulting ovulated eggs or embryos. Here we tested the hypothesis that eggs derived from superovulation have a reduced capacity to support calcium oscillations, which are a critical factor in the success of embryo development. Eggs were obtained from mice that were either naturally cycling or underwent a standard superovulation protocol. The eggs were either parthenogenetically activated using strontium or fertilized in vitro while undergoing monitoring of calcium oscillatory patterns. Following parthenogenetic activation, superovulated eggs had a slightly delayed onset and longer duration of the first calcium transient, but no differences in oscillation persistence, frequency, or total calcium signal. However, in vitro fertilized superovulated eggs had no differences in any of these measures of calcium oscillatory behavior relative to spontaneously ovulated eggs. These findings indicate that although subtle differences in calcium signaling can be detected following parthenogenetic activation, superovulation does not disrupt physiological calcium signaling at fertilization, supporting the use of this method for both clinical and experimental purposes.

2021 ◽  
Author(s):  
Virginia Savy ◽  
Paula Stein ◽  
Min Shi ◽  
Carmen J Williams

Superovulation is a common approach to maximize the number of eggs available for either clinical assisted reproductive technologies or experimental animal studies. This procedure provides supraphysiological amounts of gonadotropins to promote continued growth and maturation of ovarian follicles that otherwise would undergo atresia. There is evidence in mice, cows, sheep and humans that superovulation has a detrimental impact on the quality of the resulting ovulated eggs or embryos. Here we tested the hypothesis that eggs derived from superovulation have a reduced capacity to support calcium oscillations following fertilization, which is a critical factor in the success of embryo development. Eggs were obtained from mice that were either naturally cycling or underwent a standard superovulation protocol. Naturally cycling mice were mated to vasectomized males and vaginal plugs were checked to assure ovulation had occurred. The superovulated mice were also mated to vasectomized males for consistency of treatment across groups. The eggs were fertilized in vitro while undergoing monitoring of calcium oscillatory patterns. There were no differences in any measures of calcium oscillatory behavior, including length of the first oscillation, area under the curve of calcium signal, or frequency or persistence of oscillations. These findings indicate that superovulation does not disrupt calcium signaling at fertilization, supporting the use of this method for both clinical and experimental purposes.


2005 ◽  
Vol 17 (9) ◽  
pp. 101
Author(s):  
C. G. Grupen ◽  
R. B. Gilchrist ◽  
S. J. Schulz ◽  
L. J. Ritter ◽  
D. T. Armstrong

The marmoset monkey (Callithrix jacchus) is a valuable model for developing assisted reproductive technologies in humans and endangered primate species. Calcium ionophore treatments have been used to induce parthenogenetic activation in a number of species, but the effectiveness of this reagent in initiating marmoset embryo development has not yet been reported. The aim of this study was to determine the developmental potential of in vitro matured (IVM) marmoset oocytes, following treatment with calcium ionophore. Immature oocytes from large (LA; >1.5 mm) and small (SA; 0.67–1.5 mm) antral follicles were isolated from the ovaries of FSH-primed animals and cultured in modified G2 medium for 26–30 h at 37.0°C in 6% CO2 in air. Meiotically mature oocytes were sequentially incubated with 5 μM ionomycin for 5 min and 2 mM 6-dimethylaminopurine for 3 h and cultured in G1/G2 sequential medium at 37.0°C in 5% O2, 6% CO2, 89% N2 for 10 days. Cumulus cell expansion associated with LA oocytes (n=118) was greater than that of SA oocytes (n=212), as determined using well established classification criteria (2.7±0.1 v. 1.8±0.2; P<0.01). A greater proportion of LA oocytes completed meiosis to the metaphase-II stage compared with SA oocytes (85±7% v. 63±7%; P<0.05). Pronuclear formation was induced at similar rates in mature oocytes of both groups, but the rate of cleavage was higher for LA oocytes compared with SA oocytes (93±6% v. 66±5%; P<0.05). The number of cells per embryo was not different between the groups.This is the first study to demonstrate that calcium ionophore effectively induces parthenogenetic activation in IVM marmoset oocytes. However, the development of parthenotes was limited beyond the 8-cell stage. Further studies are needed to determine the cause of the developmental block.


GYNECOLOGY ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 113-116
Author(s):  
L A Bagdasaryan ◽  
I E Korneyeva

The aim of the study is to systematically analyze the data available in the modern literature on the relationship between endometrial thickness and the frequency of pregnancy in the program of assisted reproductive technologies (ART). Materials and methods. The review includes data from foreign and domestic articles found in PubMed on this topic. Results. The article presents data on the relationship between the thickness of the endometrium and the frequency of pregnancy in ART programs. The greatest number of studies is devoted to the evaluation of the relationship between the thickness of the endometrium and the frequency of pregnancy on the day of the ovulation trigger. Data are presented on the existence of a correlation between the thickness of the endometrium measured on the day of the ovulation trigger and the frequency of clinical pregnancy, as well as data on the need to evaluate the structure of the endometrium and the state of subendometric blood flow. The importance of multilayered (three-layered) endometrium as a prognostic marker of success in in vitro fertilization/intracytoplasmic sperm injection programs in the ovum is emphasized. The conclusion. The thickness of the endometrium can not be used as an argument for canceling the cycle or abolishing embryo transfer to the uterine cavity. Further studies in this direction are needed with a study of the morphological and molecular genetic characteristics of the endometrium, which in the future will allow us to evaluate the relationship between the thickness of the endometrium and the probability of pregnancy.


Author(s):  
N.A. Altinnik , S.S. Zenin , V.V. Komarova et all

The article discusses the factors that determine the content of the legal limitations of pre-implantation genetic diagnosis in the framework of the in vitro fertilization procedure, taking into account international experience and modern domestic regulatory legal regulation of the field of assisted reproductive technologies. The authors substantiates the conclusion that it is necessary to legislate a list of medical indications for preimplantation genetic diagnosis, as well as the categories of hereditary or other genetic diseases diagnosed in the framework of this procedure.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sandra Monfort ◽  
Carmen Orellana ◽  
Silvestre Oltra ◽  
Mónica Rosello ◽  
Alfonso Caro-Llopis ◽  
...  

AbstractDevelopment of assisted reproductive technologies to address infertility has favored the birth of many children in the last years. The majority of children born with these treatments are healthy, but some concerns remain on the safety of these medical procedures. We have retrospectively analyzed both the fertilization method and the microarray results in all those children born between 2010 and 2019 with multiple congenital anomalies, developmental delay and/or autistic spectrum disorder (n = 486) referred for array study in our center. This analysis showed a significant excess of pathogenic copy number variants among those patients conceived after in vitro fertilization with donor oocyte with respect to those patients conceived by natural fertilization (p = 0.0001). On the other hand, no significant excess of pathogenic copy number variants was observed among patients born by autologous oocyte in vitro fertilization. Further studies are necessary to confirm these results and in order to identify the factors that may contribute to an increased risk of genomic rearrangements, as well as consider the screening for genomic alterations after oocyte donation in prenatal diagnosis.


2021 ◽  
pp. medhum-2020-011864
Author(s):  
Lisa Guntram

Uterus transplantation combined with in vitro fertilisation (IVF) (henceforth called UTx-IVF) as a treatment for infertility caused by an absence or malfunction of the uterus is advancing. About 50 transplantations have been conducted worldwide and at least 14 children have been born—9 of them by women taking part in a Swedish research project on UTx-IVF. The Swedish research protocol initially stated that the potential recipient must ‘have her own donor’ who is preferably related to the recipient. But what does it mean to ask someone for a uterus? What challenges does this question instigate? And what norms may it enact? In this article, I explore how 10 women—who have considered, and sometimes pursued, UTx-IVF—describe their experiences of searching for a donor. I aim to show how an analysis of such accounts can help us unpack some of the specific relational and gendered dimensions of UTx-IVF and by doing so enrich discussions of risks, benefits, care and support in UTx-IVF. Drawing on research in social sciences and medical humanities that has demonstrated how assisted reproductive technologies and organ donation can provoke social and familial conundrums, with respect to such topics as embodiment and identity, I present three patterns that describe different dimensions of the interviewees’ quest for a uterus donor. I discuss the negotiations that took place, how expectations unfolded and how entanglements were managed as the interviewees considered asking someone for a donation. Such an examination, I suggest, contributes to make care and support more attuned to the experiences and entanglements that UTx-IVF entails for those pursuing it. This will become increasingly important if (or when) UTx-IVF becomes part of general healthcare. To conclude, I problematise responsibilities and relational challenges in medical innovation, and in this way provide insights into how the ethical debate over UTx-IVF can broaden its scope.


Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Shiori Ashibe ◽  
Kanade Irisawa ◽  
Ken Yokawa ◽  
Yoshikazu Nagao

Summary Hyaluronidase is widely used in animal and human assisted reproductive technologies (ARTs) to remove cumulus cells around oocytes. However, adverse effects of hyaluronidase treatment, such as increased rates of degeneration and parthenogenesis, have been found after treatment of human and mouse oocytes. Currently, the mechanism(s) of the detrimental effects are unclear. The present study was initiated to identify the mechanism of adverse responses to hyaluronidase treatment in bovine oocytes and early embryos. Cumulus cells were removed from cumulus–oocyte complexes (COCs) with or without hyaluronidase and the oocytes were subjected to intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). Significantly lower rates of blastocyst formation were obtained in the hyaluronidase treatment group after ICSI (22.4%) and IVF (21.2%) compared with the non-hyaluronidase control groups: 36.1% after ICSI and 30.4% after IVF. Next, we examined the effect of hyaluronidase on parthenogenetic development rates and on the cytoplasmic levels of free calcium ions (Ca2+), reactive oxygen species (ROS) and reduced glutathione (GSH). No differences in parthenogenesis rates were found between treated and untreated groups. Ca2+ levels in oocytes from the hyaluronidase treatment group indicated using mean fluorescence intensity were significantly higher (68.8 ± 5.3) compared with in the control group (45.0 ± 2.5). No differences were found in the levels of ROS or GSH between the treated and untreated groups. We conclude that hyaluronidase might trigger an increase in Ca2+ levels in oocytes, resulting in a decreased potential for normal embryonic development.


2021 ◽  
Vol 10 (12) ◽  
pp. 2687
Author(s):  
Kaan Aydos ◽  
Oya Sena Aydos

Retrieving spermatozoa from the testicles has been a great hope for patients with non-obstructive azoospermia (NOA), but relevant methods have not yet been developed to the level necessary to provide resolutions for all cases of NOA. Although performing testicular sperm extraction under microscopic magnification has increased sperm retrieval rates, in vitro selection and processing of quality sperm plays an essential role in the success of in vitro fertilization. Moreover, sperm cryopreservation is widely used in assisted reproductive technologies, whether for therapeutic purposes or for future fertility preservation. In recent years, there have been new developments using advanced technologies to freeze and preserve even very small numbers of sperm for which conventional techniques are inadequate. The present review provides an up-to-date summary of current strategies for maximizing sperm recovery from surgically obtained testicular samples and, as an extension, optimization of in vitro sperm processing techniques in the management of NOA.


Zygote ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 154-159
Author(s):  
Juliana I. Candelaria ◽  
Anna C. Denicol

SummaryPreantral follicles are a potential reservoir of oocytes to be used in assisted reproductive technologies. With the increasing interest in developing techniques to grow preantral follicles in vitro, and as the bovine emerges as an appropriate model species to understand human folliculogenesis, the establishment of an accurate classification of developmental stages is needed. Classification of bovine preantral follicles has been mostly based on histological analysis and estimation models, which may not translate well to correctly characterize preantral follicles isolated from the ovary. In this study, we classified bovine preantral follicles by morphology upon isolation, determined diameter and number of granulosa cells by direct counting, and compared our results with previous studies reporting bovine preantral follicle classification. Follicles were isolated via homogenization of ovary tissue and classified into primary, early secondary and secondary stage based on morphology and number of layers of granulosa cells. Diameter was individually measured and Hoechst 33342 was used as a nuclear stain to count granulosa cells. We found that follicles classified by morphology into primary, early secondary, and secondary had different mean diameter and cell number (P < 0.01); cell number and diameter were positively correlated, as were cell density and cell number in each developmental stage (P < 0.01). Results obtained here were mostly in agreement with previous classifications based on histological sections and on isolated follicles, with some discrepancies. The present data add accuracy to classification of bovine preantral follicles that is critical to optimize culture conditions to produce developmentally competent oocytes.


Author(s):  
Nikolai A. Ognerubov

In connection with the active development and use of assisted reproductive technologies, protection of the human embryo and its legal status issue is currently being actualized. We make an attempt to reveal and explain some of the international aspects of the criminal law protection of the life and rights of the embryo. We consider the concept of “embryo” not only from the point of view of various scientific approaches (medicine, biology, embryology, jurisprudence), but also from the legislative side. We present and analyze the first mention of the embryo in Roman private law in connection with modern domestic law. We carry out an analysis of international legal acts that provide protection of embryos both “in vitro” and “in vivo”, followed by consideration of specific criminal law norms of foreign countries, namely Brazil and Colombia. We pay attention to some of the most famous cases from the jurisprudence of the European Court of Human Rights in order to understand the applied international legal acts “de facto”. The study also takes into account modern domestic legislation and considers point “g” of part 2 of Article 105 of the Criminal Code of the Russian Federation.


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