scholarly journals Preimplantation loss of fertilized human ova: estimating the unobservable

2020 ◽  
Vol 35 (4) ◽  
pp. 743-750 ◽  
Author(s):  
Allen J Wilcox ◽  
Quaker Harmon ◽  
Kevin Doody ◽  
Don P Wolf ◽  
Eli Y Adashi
Keyword(s):  
In Vitro Fertilization ◽  
Success Rates ◽  
Multiple Sources ◽  
Vitro Fertilization ◽  
Summary Estimate ◽  
Environmental Health Sciences ◽  
Registration Number ◽  
Competing Interest

Abstract STUDY QUESTION What proportion of fertilized human ova are lost before implantation? SUMMARY ANSWER An estimated 40 to 50% of fertilized ova fail to implant. WHAT IS KNOWN ALREADY Preimplantation loss is not detectable with current technology. Published estimates of preimplantation loss range from 10 to 70%. STUDY DESIGN, SIZE, DURATION We combine data from epidemiologic, demographic, laboratory and in vitro fertilization studies to construct an empirical framework for the estimation of preimplantation loss. This framework is summarized in a user-friendly Excel file included in supplement. PARTICIPANTS/MATERIALS, SETTING, METHODS We draw from multiple sources to generate plausible estimates of fecundability, sterility, transient anovulation, intercourse patterns and the proportion of ova fertilized in the presence of sperm. We combine these estimates to generate a summary estimate of preimplantation loss. This estimate can be considered an average for couples in their prime reproductive years. MAIN RESULTS AND THE ROLE OF CHANCE Under a plausible range of assumptions, we estimate that 40 to 50% of fertilized ova fail to implant. LIMITATIONS, REASONS FOR CAUTION A crucial factor in estimating preimplantation loss is the probability that an ovum will be fertilized when exposed to sperm. Human data are available only from in vitro fertilization (IVF), which may not accurately represent events in vivo. We therefore assume a range of in vivo fertilization rates, from 64% (human IVF data) to 90% (mouse data). WIDER IMPLICATIONS OF THE FINDINGS Our estimate of preimplantation loss takes into account the biological processes relevant to fertilization and loss. Using this empirical basis for estimation, we find support for the usual assumption that risk of loss is highest in the earliest days following fertilization. Furthermore, this framework can provide improved estimates as better reproductive data become available. To the extent that our estimates are accurate, more fertilized ova are apparently lost in vitro than in vivo, suggesting that further improvements in IVF success rates may be possible. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the Intramural Program of the National Institute of Environmental Health Sciences, NIH. Professor Adashi serves as Co-Chair of the Safety Advisory Board of Ohana Biosciences, Inc. The other authors have no competing interests. TRIAL REGISTRATION NUMBER N/A.

scholarly journals In Vitro Fertilization of In Vitro and In Vivo Matured Oocytes from Prepubertal Meishan Gilts

1990 ◽  
Vol 61 (11) ◽  
pp. 1011-1016
Author(s):  
Takashi MIYANO ◽  
Kiyoshi YOSHIKAWA ◽  
Seishiro KATO ◽  
Hiroshi HARAYAMA ◽  
Iwao NANJO ◽  
...  
Keyword(s):  
In Vitro Fertilization ◽  
Vitro Fertilization

scholarly journals Robust Metabolomics Approach For The Evaluation Of Human Embryos From In-Vitro Fertilization.

2021 ◽  
Author(s):  
Cecilia Figoli ◽  
Marcelo Garcea ◽  
Claudio Bisioli ◽  
Valeria Tafintseva ◽  
Volha Shapaval ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
In Vitro Fertilization ◽  
Selection Criterion ◽  
Human Embryos ◽  
Spectral Features ◽  
Success Rates ◽  
Vitro Fertilization ◽  
Main Challenge ◽  
Culture Supernatants

Abstract The identification of the most competent embryos for transfer to the uterus constitutes the main challenge of in-vitro fertilization (IVF). We established a metabolomic-based approach applying Fourier Transform Infrared spectroscopy (FTIR) on 130 samples of 3-days embryo culture supernatants from 26 embryos that implanted and 104 that failed. Examining the internal structure of the data by unsupervised multivariate analysis, it was observed that the supernatants of nonimplanted embryos contained highly heterogeneous spectral features. These features were overlapping with metabolic-implantation fingerprints, thus demonstrating that in establishing embryo-assessment models a one-class modelling involving only the samples with positive-implantation outcomes should be applied. Analysis of variance confirmed that the women´s age (>40 years) undermined the implantation of the embryos exhibiting implantation metabolomics, and also that constituted a condition triggering embryos to express nonimplantation metabolomics. We conclude that IVF-success rates can be significantly improved if FTIR spectroscopy is used as an embryo-selection criterion.

scholarly journals Piglets produced by transfer of embryos obtained by in vitro fertilization of oocytes matured in vitro with thymosin: A case report

2020 ◽  
Vol 76 (03) ◽  
pp. 6356-2020 ◽  
Author(s):  
KATARZYNA PONIEDZIAŁEK-KEMPNY ◽  
BARBARA GAJDA ◽  
IWONA RAJSKA ◽  
LECHOSŁAW GAJDA ◽  
ZDZISŁAW SMORĄG
Keyword(s):  
Case Report ◽  
In Vitro Fertilization ◽  
Control Group ◽  
First Birth ◽  
Vitro Fertilization ◽  
Research Material ◽  
Preliminary Study ◽  
Experimental Group

The aim of the study was to examine the in vivo viability of in vitro-produced (IVP) porcine embryos obtained from oocytes matured with thymosin. The research material for this study consisted of immature pig oocytes obtained from ovaries after slaughter and ejaculated semen obtained from one boar. The immature oocytes were cultured in vitro until the metaphase II stage in a medium supplemented with thymosin (TMS). The presumptive zygotes obtained were cultured in vitro for 4-40 hours. The presumptive zygotes and 2-4-cell embryos were evaluated in vivo after transferring them to synchronized recipients. After the transfer of embryos from the experimental group into 2 recipients (50 embryos into each gilt) and the transfer of 50 embryos from the control group into 1 recipient, both gilts that had received embryos obtained by in vitro fertilization of oocytes matured with TMS became pregnant and delivered a total of 16 live piglets. After the transfer of embryos from the control group, no pregnancy was achieved. In conclusion, the results of our preliminary study suggest that the maturation of pig oocytes with thymosin supports the in vivo survival of in vitro produced embryos. It is important to note, that this was the first birth of piglets obtained after transfer of IVP embryos in Poland.

scholarly journals The obligate need for accuracy in reporting preclinical studies relevant to clinical trials: autologous germline mitochondrial supplementation for assisted human reproduction as a case study

2020 ◽  
Vol 14 ◽  
pp. 263349412091735
Author(s):  
Jonathan L. Tilly ◽  
Dori C. Woods
Keyword(s):  
Energy Transfer ◽  
In Vitro Fertilization ◽  
Clinical Studies ◽  
Human Reproduction ◽  
Fertility Treatment ◽  
Success Rates ◽  
Vitro Fertilization ◽  
Mouse Study ◽  
Mitochondrial Supplementation

A now large body of work has solidified the central role that mitochondria play in oocyte development, fertilization, and embryogenesis. From these studies, a new technology termed autologous germline mitochondrial energy transfer was developed for improving pregnancy success rates in assisted reproduction. Unlike prior clinical studies that relied on the use of donor, or nonautologous, mitochondria for microinjection into eggs of women with a history of repeated in vitro fertilization failure to enhance pregnancy success, autologous germline mitochondrial energy transfer uses autologous mitochondria collected from oogonial stem cells of the same woman undergoing the fertility treatment. Initial trials of autologous germline mitochondrial energy transfer during - in vitro fertilization at three different sites with a total of 104 patients indicated a benefit of the procedure for improving pregnancy success rates, with the birth of children conceived through the inclusion of autologous germline mitochondrial energy transfer during in vitro fertilization. However, a fourth clinical study, consisting of 57 patients, failed to show a benefit of autologous germline mitochondrial energy transfer– in vitro fertilization versus in vitro fertilization alone for improving cumulative live birth rates. Complicating this area of work further, a recent mouse study, which claimed to test the long-term safety of autologous mitochondrial supplementation during in vitro fertilization, raised concerns over the use of the procedure for reproduction. However, autologous mitochondria were not actually used for preclinical testing in this mouse study. The unwarranted fears that this new study’s erroneous conclusions could cause in women who have become pregnant through the use of autologous germline mitochondrial energy transfer during- in vitro fertilization highlight the critical need for accurate reporting of preclinical work that has immediate bearing on human clinical studies.

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