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Developmental Cell Jan 2022There has been recent renewed interest in studying human early embryonic development. The advent of improved culture conditions to maintain blastocysts in vitro for an... (Review)
Review
There has been recent renewed interest in studying human early embryonic development. The advent of improved culture conditions to maintain blastocysts in vitro for an extended period and the emerging stem-cell-based models of the blastocyst and peri-implantation embryos have provided new information that is relevant to early human embryogenesis. However, the mechanism of lineage development and embryonic patterning, and the molecular pathways involved in their regulation, are still not well understood. Interest in human embryonic development has been reinvigorated recently given numerous technical advances. In this review, Rossant and Tam discuss new insights into human embryogenesis gathered from successes in culturing human embryos in vitro and stem-cell-based embryo models. Then they outline what questions still need answering.
Topics: Blastocyst; Body Patterning; Cell Lineage; Embryo Culture Techniques; Embryo, Mammalian; Embryonic Development; Embryonic Stem Cells; Gastrulation; Gene Expression Regulation, Developmental; Humans
PubMed: 35077679
DOI: 10.1016/j.devcel.2021.12.022 -
Fertility and Sterility Jun 2000To determine the relationship between blastocyst score and pregnancy outcome.
OBJECTIVE
To determine the relationship between blastocyst score and pregnancy outcome.
DESIGN
Retrospective review of blastocyst transfer in an IVF clinic.
SETTING
Private assisted reproductive technology unit.
PATIENT(S)
107 patients undergoing blastocyst culture and transfer of two embryos.
INTERVENTION(S)
Culture of all pronucleate embryos in sequential media to the blastocyst stage (day 5), followed by transfer of two blastocysts.
MAIN OUTCOME MEASURE(S)
Implantation rates, pregnancy rates, and twinning were analyzed.
RESULT(S)
When a patient received two top-scoring blastocysts (64% of patients), implantation and pregnancy rates were 70% and 87%, respectively. The twinning rate in this group was 61%. When only one top-quality blastocyst was available for transfer (21% of patients), the implantation and pregnancy rates were 50% and 70%. The twinning rate for this group was 50%. In contrast, when only low-scoring blastocysts were available for transfer (15% of patients), implantation and pregnancy rates were 28% and 44%, and the twinning rate was 29%. No monozygotic twins were observed in this group of patients.
CONCLUSION(S)
The ability to transfer one high-scoring blastocyst should lead to pregnancy rates greater than 60%, without the complication of twins.
Topics: Adult; Blastocyst; Embryo Implantation; Embryo Transfer; Female; Fertilization in Vitro; Humans; Pregnancy; Pregnancy Outcome; Pregnancy Rate; Pregnancy, Multiple; Retrospective Studies; Twins
PubMed: 10856474
DOI: 10.1016/s0015-0282(00)00518-5 -
Fertility and Sterility Mar 2014To determine the relationship between the age of the female partner and the prevalence and nature of human embryonic aneuploidy. (Review)
Review
The nature of aneuploidy with increasing age of the female partner: a review of 15,169 consecutive trophectoderm biopsies evaluated with comprehensive chromosomal screening.
OBJECTIVE
To determine the relationship between the age of the female partner and the prevalence and nature of human embryonic aneuploidy.
DESIGN
Retrospective.
SETTING
Academic.
PATIENT(S)
Trophectoderm biopsies.
INTERVENTION(S)
Comprehensive chromosomal screening performed on patients with blastocysts available for biopsy.
MAIN OUTCOME MEASURE(S)
Evaluation of the impact of maternal age on the prevalence of aneuploidy, the probability of having no euploid embryos within a cohort, the complexity of aneuploidy as gauged by the number of aneuploid chromosomes, and the trisomy/monosomy ratio.
RESULT(S)
Aneuploidy increased predictably after 26 years of age. A slightly increased prevalence was noted at younger ages, with >40% aneuploidy in women 23 years and under. The no euploid embryo rate was lowest (2% to 6%) in women aged 26 to 37, was 33% at age 42, and was 53% at age 44. Among the biopsies with aneuploidy, 64% involved a single chromosome, 20% two chromosomes, and 16% three chromosomes, with the proportion of more complex aneuploidy increasing with age. Finally, the trisomy/monosomy ratio approximated 1 and increased minimally with age.
CONCLUSION(S)
The lowest risk for embryonic aneuploidy was between ages 26 and 30. Both younger and older age groups had higher rates of aneuploidy and an increased risk for more complex aneuploidies. The overall risk did not measurably change after age 43. Trisomies and monosomies are equally prevalent.
Topics: Adult; Aneuploidy; Biopsy; Blastocyst; Cohort Studies; Ectoderm; Female; Genetic Testing; Humans; Maternal Age; Middle Aged; Retrospective Studies; Young Adult
PubMed: 24355045
DOI: 10.1016/j.fertnstert.2013.11.004 -
Proceedings of the National Academy of... Jul 2019Preimplantation genetic testing for aneuploidy (PGT-A) with trophectoderm (TE) biopsy is widely applied in in vitro fertilization (IVF) to identify aneuploid embryos....
Preimplantation genetic testing for aneuploidy (PGT-A) with trophectoderm (TE) biopsy is widely applied in in vitro fertilization (IVF) to identify aneuploid embryos. However, potential safety concerns regarding biopsy and restrictions to only those embryos suitable for biopsy pose limitations. In addition, embryo mosaicism gives rise to false positives and false negatives in PGT-A because the inner cell mass (ICM) cells, which give rise to the fetus, are not tested. Here, we report a critical examination of the efficacy of noninvasive preimplantation genetic testing for aneuploidy (niPGT-A) in the spent culture media of human blastocysts by analyzing the cell-free DNA, which reflects ploidy of both the TE and ICM. Fifty-two frozen donated blastocysts with TE biopsy results were thawed; each of their spent culture medium was collected after 24-h culture and analyzed by next-generation sequencing (NGS). niPGT-A and TE-biopsy PGT-A results were compared with the sequencing results of the corresponding embryos, which were taken as true results for aneuploidy reporting. With removal of all corona-cumulus cells, the false-negative rate (FNR) for niPGT-A was found to be zero. By applying an appropriate threshold for mosaicism, both the positive predictive value (PPV) and specificity for niPGT-A were much higher than TE-biopsy PGT-A. Furthermore, the concordance rates for both embryo ploidy and chromosome copy numbers were higher for niPGT-A than TE-biopsy PGT-A. These results suggest that niPGT-A is less prone to errors associated with embryo mosaicism and is more reliable than TE-biopsy PGT-A.
Topics: Adult; Aneuploidy; Biopsy; Blastocyst; Blastocyst Inner Cell Mass; Cell-Free Nucleic Acids; Culture Media; Female; Fertilization in Vitro; Genetic Testing; High-Throughput Nucleotide Sequencing; Humans; Karyotype; Noninvasive Prenatal Testing; Pregnancy; Preimplantation Diagnosis
PubMed: 31235575
DOI: 10.1073/pnas.1907472116 -
Journal of Assisted Reproduction and... Nov 2020A published study reported by Munné using uterine lavage to retrieve in vivo blastocysts for preimplantation genetic testing has been the subject of several technical...
A published study reported by Munné using uterine lavage to retrieve in vivo blastocysts for preimplantation genetic testing has been the subject of several technical and ethical critiques. None of these critiques has been based on a review of the study's IRB-approved informed consent. This commentary seeks to do that, examining the Munné (and related Nadal) consent forms for their conformity to existing requirements for a full and informed consent.
Topics: Blastocyst; Female; Humans; Informed Consent; Pregnancy; Preimplantation Diagnosis; Risk Assessment; Uterus
PubMed: 32909118
DOI: 10.1007/s10815-020-01938-9 -
Journal of Ovarian Research Mar 2021High-quality single blastocyst transfer (SBT) is increasingly recommended to patients because of its acceptable pregnancy outcomes and significantly reduced multiple...
BACKGROUND
High-quality single blastocyst transfer (SBT) is increasingly recommended to patients because of its acceptable pregnancy outcomes and significantly reduced multiple pregnancy rate compared to double blastocyst transfer (DBT). However, there is no consensus on whether this transfer strategy is also suitable for poor-quality blastocysts. Moreover, the effect of the development speed of poor-quality blastocysts on pregnancy outcomes has been controversial. Therefore, this study aimed to explore the effects of blastocyst development speed and morphology on pregnancy and neonatal outcomes during the frozen embryo transfer (FET) cycle of poor-quality blastocysts and to ultimately provide references for clinical transfer strategies.
METHODS
A total of 2,038 FET cycles of poor-quality blastocysts from patients 40 years old or less were included from January 2014 to December 2019 and divided based on the blastocyst development speed and number of embryos transferred: the D5-SBT (n = 476), D5-DBT (n = 365), D6-SBT (n = 730), and D6-DBT (n = 467) groups. The SBT group was further divided based on embryo morphology: D5-AC/BC (n = 407), D5-CA/CB (n = 69), D6-AC/BC (n = 580), and D6-CA /CB (n = 150).
RESULTS
When blastocysts reach the same development speed, the live birth and multiple pregnancy rates of DBT were significantly higher than those of SBT. Moreover, there was no statistical difference in the rates of early miscarriage and live birth between the AC/BC and CA/CB groups. When patients in the SBT group were stratified by blastocyst development speed, the rates of clinical pregnancy (42.44 % vs. 20.82 %) and live birth (32.35 % vs. 14.25 %) of D5-SBT group were significantly higher than those of D6-SBT group. Furthermore, for blastocysts in the same morphology group (AC/BC or CA/CA group), the rates of clinical pregnancy and live birth in the D5 group were also significantly higher than those of D6 group.
CONCLUSIONS
For poor-quality D5 blastocysts, SBT can be recommended to patients because of acceptable pregnancy outcomes and significantly reduced multiple pregnancy rate compared with DBT. For poor-quality D6, the DBT strategy is recommended to patients to improve pregnancy outcomes. When blastocysts reach the same development speed, the transfer strategy of selecting blastocyst with inner cell mass "C" or blastocyst with trophectoderm "C" does not affect the pregnancy and neonatal outcomes.
Topics: Adult; Blastocyst; Embryo Culture Techniques; Embryo Implantation; Female; Humans; Pregnancy; Retrospective Studies; Treatment Outcome; Vitrification
PubMed: 33789698
DOI: 10.1186/s13048-021-00798-w -
Stem Cell Reports Nov 2022The recent derivation of human trophoblast stem cells (TSCs) from placental cytotrophoblasts and blastocysts opened opportunities for studying the development and...
The recent derivation of human trophoblast stem cells (TSCs) from placental cytotrophoblasts and blastocysts opened opportunities for studying the development and function of the human placenta. Recent reports have suggested that human naïve, but not primed, pluripotent stem cells (PSCs) retain an exclusive potential to generate TSCs. Here we report that, in the absence of WNT stimulation, transforming growth factor β (TGF-β) pathway inhibition leads to direct and robust conversion of primed human PSCs into TSCs. The resulting primed PSC-derived TSC lines exhibit self-renewal, can differentiate into the main trophoblast lineages, and present RNA and epigenetic profiles that are indistinguishable from recently established TSC lines derived from human placenta, blastocysts, or isogenic human naïve PSCs expanded under human enhanced naïve stem cell medium (HENSM) conditions. Activation of nuclear Yes-associated protein (YAP) signaling is sufficient for this conversion and necessary for human TSC maintenance. Our findings underscore a residual plasticity in primed human PSCs that allows their in vitro conversion into extra-embryonic trophoblast lineages.
Topics: Female; Humans; Pregnancy; Blastocyst; Cell Differentiation; Placenta; Pluripotent Stem Cells; Trophoblasts
PubMed: 36270280
DOI: 10.1016/j.stemcr.2022.09.008 -
Communications Biology Mar 2021Approaches to reliably predict the developmental potential of embryos and select suitable embryos for blastocyst culture are needed. The development of time-lapse...
Approaches to reliably predict the developmental potential of embryos and select suitable embryos for blastocyst culture are needed. The development of time-lapse monitoring (TLM) and artificial intelligence (AI) may help solve this problem. Here, we report deep learning models that can accurately predict blastocyst formation and usable blastocysts using TLM videos of the embryo's first three days. The DenseNet201 network, focal loss, long short-term memory (LSTM) network and gradient boosting classifier were mainly employed, and video preparation algorithms, spatial stream and temporal stream models were developed into ensemble prediction models called STEM and STEM. STEM exhibited 78.2% accuracy and 0.82 AUC in predicting blastocyst formation, and STEM achieved 71.9% accuracy and 0.79 AUC in predicting usable blastocysts. We believe the models are beneficial for blastocyst formation prediction and embryo selection in clinical practice, and our modeling methods will provide valuable information for analyzing medical videos with continuous appearance variation.
Topics: Algorithms; Blastocyst; Deep Learning; Embryonic Development; Humans; Time-Lapse Imaging
PubMed: 33772211
DOI: 10.1038/s42003-021-01937-1 -
Journal of Assisted Reproduction and... Aug 2013To review the history of experimental embryo culture and how culture media that permitted complete preimplantation development in vitro were first discovered, and the... (Review)
Review
PURPOSE
To review the history of experimental embryo culture and how culture media that permitted complete preimplantation development in vitro were first discovered, and the physiological insights gained.
METHODS
This article reviews the history of in vitro mammalian embryo culture, in particular the efforts that led to the current generation of successful culture media and how these reflect embryo physiology, highlighting the contributions of Dr. John D. Biggers and his colleagues and students.
RESULTS
The culture of mammalian embryos began about a century ago. However, defined media without biological fluids were only developed in the late 1950s, and the first live young born from cultured embryos, using these media, were produced by McLaren and Biggers in 1958. It wasn’t until the late 1980s, however, that preimplantation mammalian embryos could generally be cultured in vitro from fertilized eggs to blastocysts. These new media led to insights into embryo physiology, including the importance of cell volume homeostasis to early embryo viability.
CONCLUSIONS
The development of successful preimplantation embryo culture media has had a profound effect on assisted reproduction technologies and on research into early embryo physiology.
Topics: Animals; Blastocyst; Culture Media; Embryo Culture Techniques; Embryo, Mammalian; Embryonic Development; Fertilization in Vitro; History, 20th Century; Humans
PubMed: 24077810
DOI: 10.1007/s10815-013-0095-x -
Journal of Ovarian Research Aug 2021Preimplantation genetic testing (PGT) is offered to a wide range of structural and numerical chromosomal imbalances, with PGT- polymerase chain reaction (PCR), as the...
BACKGROUND
Preimplantation genetic testing (PGT) is offered to a wide range of structural and numerical chromosomal imbalances, with PGT- polymerase chain reaction (PCR), as the method of choice for amplifying the small DNA content achieved from the blastomere biopsy or trophectoderm (TE) biopsy, that might have a detrimental impact on embryonic implantation potential. Since human embryos cultured until Day-5-6 were noticed to expel cell debris/ fragments within the zona pellucida, we aimed to examine whether these cell debris/ fragments might be used for PGT, as an alternative to embryo biopsy.
METHODS
Blastocysts, which their Day-3 blastomere biopsy revealed an affected embryo with single-gene defect, and following hatching leaved cell debris/fragments within the zona pellucida were analyzed. Each blastocyst and its corresponding cell debris/fragments were separated and underwent the same molecular analysis, based on multiplex PCR programs designed for haplotyping using informative microsatellites markers. The main outcome measure was the intra-embryo congruity of Day-3 blastomere biopsy and its corresponding blastocyst and cell debris/fragments.
RESULTS
Fourteen affected embryos from 9 women were included. Only 8/14 (57.2%) of embryos demonstrated congruent molecular genetic results between Day-3 embryo and its corresponding blastocyst and cell debris/fragments. In additional 6/14 (42.8%) embryos, molecular results of the Day-3 embryos and their corresponding blastocysts were congruent, while the cell debris/fragments yielded no molecular diagnoses (incomplete diagnoses).
CONCLUSIONS
It might be therefore concluded, that in PGT cycles, examining the cell debris/fragments on Day-4, instead of Day-3 blastomere or Day-5 TE biopsies, is feasible and might avoid embryo biopsy with its consequent detrimental effect on embryos' implantation potential. Whenever the latter results in incomplete diagnosis, TE biopsy should be carried out on Day-5 for final genetic results. Further large well-designed studies are required to validate the aforementioned PGT platform.
Topics: Adult; Blastocyst; Embryo Implantation; Female; Genetic Testing; Humans; Pregnancy; Preimplantation Diagnosis
PubMed: 34380524
DOI: 10.1186/s13048-021-00853-6