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Journal of Assisted Reproduction and... Sep 2019The aim was to evaluate mtDNA content and its dynamics in euploid and aneuploid embryos from cleavage to blastocyst stage following consecutive biopsies. The effect of...
PURPOSE
The aim was to evaluate mtDNA content and its dynamics in euploid and aneuploid embryos from cleavage to blastocyst stage following consecutive biopsies. The effect of female age on mtDNA content was evaluated by comparing reproductively younger (≤ 37 years) with older (> 37 years) women.
METHODS
A retrospective single-centre descriptive study was performed between August 2016 and January 2017. Forty patients, with 112 embryos, undergoing preimplantation genetic testing for aneuploidies (PGT-A) by next-generation sequencing (NGS) were included. Embryos that reached the blastocyst stage and were not selected for fresh embryo transfer were included following consecutive biopsies of a single blastomere on day 3 and trophectoderm biopsy of day 5 blastocysts.
RESULTS
Cleavage-stage mtDNA was significantly lower in fast cleaving embryos (p = 0.016). Based on the concordance between day 3 and day 5 biopsies, a difference was identified in blastocyst mtDNA content between groups (p = 0.019); true euploid blastocysts presented a lower mtDNA content. No association was identified between cleavage-stage mtDNA content and ploidy status (OR 1.008 [0.981-1.036], p = 0.565) nor between blastocyst mtDNA content and ploidy outcome (OR 0.954 [0.898-1.014], p = 0.129). No difference was found when comparing mtDNA content and ploidy outcome between the two reproductive age groups (p = 0.505 (cleavage stage) and p = 0.774 (blastocyst)).
CONCLUSION
Mitochondrial DNA content of cleavage-stage embryos and blastocysts is unable to predict ploidy status. Subgroup analysis based on ploidy concordance between day 3 and day 5 revealed a significantly lower mtDNA content for true euploid blastocysts. Reproductive ageing does not affect mtDNA content.
Topics: Adult; Aneuploidy; Blastocyst; Blastomeres; DNA, Mitochondrial; Embryo Implantation; Embryo Transfer; Female; Humans; Maternal Age; Middle Aged; Ploidies; Pregnancy; Retrospective Studies; Young Adult
PubMed: 31392663
DOI: 10.1007/s10815-019-01544-4 -
Chinese Medical Journal Jun 2018Despite recent advances that have improved the pregnancy success rates that can be achieved via in vitro fertilization (IVF) therapy, it is not yet clear which...
BACKGROUND
Despite recent advances that have improved the pregnancy success rates that can be achieved via in vitro fertilization (IVF) therapy, it is not yet clear which blastocyst morphological parameters best predict the outcomes of single blastocyst transfer. In addition, most of the previous studies did not exclude the effect of embryo aneuploidy on blastocysts transfer. Thus, the present study investigated the predictive value of various parameters on the pregnancy outcomes achieved via the transfer of frozen euploid blastocysts.
METHODS
The study retrospectively analyzed 914 single euploid blastocyst transfer cycles that were performed at the Peking University Third Hospital Reproductive Medical Center between June 2011 and May 2016. The expansion, trophectoderm (TE), and inner cell mass (ICM) quality of the blastocysts were assessed based on blastocyst parameters, and used to differentiate between "excellent", "good", "average", and "poor"-quality embryos. The relationship between these embryo grades and the achieved pregnancy outcomes was then analyzed via the Chi-square and logistic regression tests.
RESULTS
For embryo grades of excellent, good, average and poor, the clinical pregnancy rates were 65.0%, 59.3%, 50.3% and 33.3%, respectively; and the live-birth rates were 50.0%, 49.7%, 42.3% and 25.0%, respectively. Both the clinical pregnancy rate (χ = 21.28, P = 0.001) and live-birth rate (χ = 13.50, P < 0.001) increased with the overall blastocyst grade. Both rates were significantly higher after the transfer of a blastocyst that exhibited either an A-grade or B-grade TE, and similarly, an A-grade ICM, than after the transfer of a blastocyst that exhibited a C-grade TE and/or ICM. The degree of blastocyst expansion had no apparent effect on the clinical pregnancy or live-birth rate. All odds ratio were adjusted for patient age, body mass index, length (years) of infertility history, and infertility type.
CONCLUSIONS
A higher overall euploid blastocyst quality is shown to correlate most strongly with optimal pregnancy outcomes. The study thus supports the use of the described TE and ICM morphological grades to augment current embryo selection criteria.
Topics: Blastocyst; Chi-Square Distribution; Embryo Transfer; Female; Humans; Logistic Models; Odds Ratio; Pregnancy; Pregnancy Outcome; Retrospective Studies
PubMed: 29786036
DOI: 10.4103/0366-6999.232808 -
Fertility and Sterility Jun 2018To study whether late spontaneous vacuolization on day 4 is an artefact or an alternate means of blastocele formation and to analyze its impact on pregnancy outcome and... (Observational Study)
Observational Study
OBJECTIVE
To study whether late spontaneous vacuolization on day 4 is an artefact or an alternate means of blastocele formation and to analyze its impact on pregnancy outcome and live birth.
DESIGN
Prospective observational study.
SETTING
University teaching hospital.
PATIENT(S)
A total of 424 patients who fulfilled inclusion criteria were subgrouped according to the spontaneous vacuolization on day 4: Group 1 had all morulas affected, group 2 showed no signs of vacuoles, and group 3 was mixed (some day 4 embryos had vacuoles and others did not).
INTERVENTION(S)
Screening for the presence of vacuoles on day 4 and fresh single-blastocyst transfer.
MAIN OUTCOME MEASURE(S)
Morula and blastocyst scoring, utilization rate, pregnancy and live birth rates.
RESULT(S)
Patients of group 1 had a reduced blastocyst formation rate on day 5 (P<.01) and significantly fewer good-quality blastocysts for usage (P<.05). In addition, pregnancy (P<.001) and live birth (P<.01) rate were significantly worse in group 1 compared with groups 2 and 3.
CONCLUSION(S)
Late onset of vacuolization around compaction stage is a negative predictor of blastocyst formation and outcome.
Topics: Adult; Birth Rate; Blastocyst; Cell Survival; Embryo Implantation; Embryo Transfer; Embryonic Development; Female; Humans; Morula; Pregnancy; Pregnancy Outcome; Pregnancy Rate; Quality Control; Vacuoles
PubMed: 29935640
DOI: 10.1016/j.fertnstert.2018.02.131 -
Journal of Ovarian Research Jan 2021Standard morphologic evaluation has been the most widely adopted approach to embryo selection, and remains the most common strategy.The objective of the study to...
BACKGROUND
Standard morphologic evaluation has been the most widely adopted approach to embryo selection, and remains the most common strategy.The objective of the study to determine the association between the morphologic grading and implantation rate of euploid blastocysts in single frozen-thawed embryo transfer (SET) cycles.
METHODS
A total of 271 patients aged 20-40 years undergoing euploid SET from January 2017 to December 2019 were included in retrospective cohort study.The cycles were divided into three groups based on their morphologic grading before cryopreservation: good-quality (n = 58), average-quality (n = 88) and poor-quality blastocysts (n = 125). The pregnancy outcome of the three morphologic groups were analyzed and a logistic regression of implantation rate was conducted.
RESULTS
Good-quality blastocysts yielded statistically significantly higher implantation rates than poor-quality (79.31% vs. 48%; P<0.001). Planned subgroup analyses by age and the day of TE biopsy were conducted. Logistic regression analyses that adjusted for these variables identified higher implantation rates (adjusted odds ratio(aOR) = 4.083, 95% confidence interval (CI):1.836-9.082, P<0.001) for the good-quality blastocysts than for those that underwent poor-quality cycles in women aged < 35 years, but not in women aged ≥35 years (aOR = 6.074, 95% CI: 0.456-80.919, P = 0.172). The implantation rates were higher among women with good-quality blastocysts on both Day 5 and Day 6 of TE biopsy than among those with poor-quality blastocysts (Day 5, aOR = 3.294, 95% CI:1.260-8.616, P = 0.015; Day 6, aOR = 4.179, 95% CI:1.004 ~ 17.399, P = 0.049). Day 5 euploid blastocysts had no significant difference in implantation potential and early spontaneous abortion rate compared with similarly graded Day 6 euploid blastocysts.
CONCLUSIONS
Blastocyst morphologic grading was associated with implantation rate for euploid embryo transfers after adjustment for potential confounders. These findings suggest that evaluating blastocyst morphology is critical when selecting the best euploid blastocyst.
Topics: Adult; Blastocyst; Embryo Implantation; Embryonic Development; Female; Humans; Pregnancy; Young Adult
PubMed: 33485390
DOI: 10.1186/s13048-021-00770-8 -
Fertility and Sterility Jun 2022To determine what patient and embryo characteristics are correlated with the developmental potential of the peri-implantation embryo.
OBJECTIVE
To determine what patient and embryo characteristics are correlated with the developmental potential of the peri-implantation embryo.
DESIGN
Retrospective study.
SETTING
Research laboratory.
PATIENTS
Six hundred fifty-one cryopreserved human blastocysts donated for research with informed patient consent.
INTERVENTIONS
Not applicable.
MAIN OUTCOME MEASURES
Blastocyst attachment to fibronectin-coated plates, trophectoderm outgrowth area, epiblast cell number, total cell number, human chorionic gonadotropin secretion.
RESULTS
Patients' body mass index, age, follicle-stimulating hormone: luteinizing hormone ratio on menstrual cycle day 3, antral follicle count on menstrual cycle day 3, antimüllerian hormone level on menstrual cycle day 3, and blastocyst morphological grade were correlated with peri-implantation development outcomes. After controlling for good-quality morphological grades, blastocysts from patients of advanced maternal age developed fewer epiblast cells than blastocysts from younger patients.
CONCLUSIONS
Extended embryo culture during the peri-implantation period mirrors several disparities in fertility treatment outcome that we see clinically, including those from patients with advanced maternal age, high body mass index, and low ovarian reserve and from embryos with lower-quality morphological grades. This model system may be useful by providing an alternative or more sensitive endpoint assessment in studying patient, clinical, or laboratory factors that may influence preimplantation embryo developmental potential.
Topics: Aneuploidy; Blastocyst; Embryo Culture Techniques; Embryo Implantation; Embryonic Development; Female; Humans; Retrospective Studies
PubMed: 35367060
DOI: 10.1016/j.fertnstert.2022.02.018 -
Human Genomics Jan 2020To compare the concordance between trophectoderm (TE) analysis and whole blastocyst analysis of embryos from chromosomal structural rearrangement (SR) carriers.
BACKGROUND
To compare the concordance between trophectoderm (TE) analysis and whole blastocyst analysis of embryos from chromosomal structural rearrangement (SR) carriers.
METHOD
Sixty-three abnormal blastocysts identified by preimplantation genetic testing for chromosomal structural rearrangement (PGT-SR) were included. The whole blastocysts were processed through multiple displacement amplification cycle and sequenced for 24-chromosome aneuploidy screening by next-generation sequencing (NGS). The sequencing results were compared with those of TE biopsy from the same blastocysts and the primary chromosomal rearrangement of the couples.
RESULTS
Analysis of the 63 blastocysts showed 68% (43/63) complete concordance between TE sequencing analysis and whole blastocyst results. Approximately one third (20/63, 32%) of the sequencing results showed some level of discordance between the two samples. Of these, 14% (9/63) of the embryos were identified as euploid after whole blastocyst sequencing. Among them, seven blastocysts were classified as chromosome mosaicism (five whole chromosomes, two segmental) after TE analysis, while two displayed non-SR related segmental changes in the TE biopsy. Of the original analyses, 70% (44/63) of findings were associated with the primary parental chromosomal rearrangement, while 30% (19/63) had no association.
CONCLUSIONS
TE biopsy with NGS for PGT-SR is an efficient strategy to identify embryos suitable for transfer. While there was a high concordance between TE and whole blastocyst chromosome results, some embryos classified as mosaic in the original analysis and therefore unsuitable for transfer were reclassified as chromosomally balanced. To maximize the number of embryos available for PGT-SR patients, we suggest that embryos with mosaic non-SR chromosomal rearrangement should be stored and considered for transfer after appropriate counseling.
Topics: Aneuploidy; Biopsy; Blastocyst; Chromosome Aberrations; Female; Genetic Testing; High-Throughput Nucleotide Sequencing; Humans; Pregnancy; Preimplantation Diagnosis; Trophoblasts
PubMed: 31931889
DOI: 10.1186/s40246-019-0253-z -
Fertility and Sterility Oct 2011To explore the occurrence of ploidy and parental self-correction in tripronuclear (TPN) human embryos. (Comparative Study)
Comparative Study
OBJECTIVE
To explore the occurrence of ploidy and parental self-correction in tripronuclear (TPN) human embryos.
DESIGN
Experimental.
SETTING
Research facility.
PATIENT(S)
Thirty-two TPN embryos resulting from intracytoplasmic sperm injection (ICSI-TPN) and 18 TPN embryos resulting from conventional IVF (IVF-TPN).
INTERVENTION(S)
Tripronuclear embryos were cultured in vitro for 6 days. Those with ≥ 6 cells were biopsied for ploidy analysis. Blastocysts were studied for ploidy or parental inheritance. Heteroparental inheritance was determined after comparing polymorphic loci in the genomic DNA of a blastocyst and in the parents' DNA.
MAIN OUTCOME MEASURE(S)
Tripronuclear origin, cell number at biopsy, chromosome analysis using fluorescent in situ hybridization, parental inheritance analysis using polymerase chain reaction amplification and sequencing, in vitro development to the blastocyst stage, and percentage of diploid and triploid cleavage embryos and blastocysts.
RESULT(S)
Half of ICSI-TPN embryos became self-corrected blastocysts whereas only one IVF-TPN embryo did.
CONCLUSION(S)
Both ICSI-TPN and IVF-TPN embryos are capable of self-correction, but the latter to a lesser extent. Neither parental inheritance nor ploidy determines the ability of a TPN embryo to progress to the blastocyst stage. However, the ability of a TPN embryo to become self-corrected is determined by the parental origin of the extra pronucleus.
Topics: Blastocyst; Cell Nucleus; Embryo Transfer; Female; Humans; Male; Organ Culture Techniques; Ploidies; Sperm Injections, Intracytoplasmic
PubMed: 21851936
DOI: 10.1016/j.fertnstert.2011.07.1087 -
Biomolecular Concepts Dec 2018Extracellular histones support rodent and human embryo development in at least two ways. First, these molecules in uterine secretions protect embryos from inflammation... (Review)
Review
Extracellular histones support rodent and human embryo development in at least two ways. First, these molecules in uterine secretions protect embryos from inflammation caused by pathogens that gain access to the reproductive tract. Also, histones in uterine secretions likely support penetration of the uterine epithelium by blastocysts during embryo implantation. Extracellular histones seem to preserve amino acid transport system B0,+ in blastocysts by inhibiting its activity. Preservation of system B0,+ is needed because, at the time of invasion of the uterine epithelium by motile trophoblasts, system B0,+ is likely reactivated to help remove tryptophan from the implantation chamber. If tryptophan is not removed, T-cells proliferate and reject the implanting blastocyst. Epigenetic modification of histones could alter their promotion of normal implantation through, say, incomplete tryptophan removal and, thus, allow partial T-cell rejection of the conceptus. Such partial rejection could impair placental development, embryonal/fetal nutrition, and weight gain prior to birth. Small-for-gestational-age offspring are predisposed to developing metabolic syndrome, obesity, and associated complications as adults. Shifting expression of these phenotypes might contribute to transgenerational variation and evolution. The spectrum of possible extracellular histone targets in early development warrant new research, especially since the effects of epigenetic histone modifications might be transgenerational.
Topics: Animals; Blastocyst; Epigenesis, Genetic; Female; Histone Code; Phenotype; Uterus
PubMed: 30864391
DOI: 10.1515/bmc-2018-0017 -
Molecular Human Reproduction Aug 2016We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0? (Review)
Review
STUDY QUESTION
We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0?
STUDY FINDING
Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS.
WHAT IS KNOWN ALREADY
It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst stage is currently called into question.
STUDY DESIGN, SAMPLES/MATERIALS, METHODS
A questionnaire was developed on the three major aspects of PGS 2.0: the Why, with general questions such as PGS 2.0 indications; the How, specifically on genetic analysis methods; the When, on the ideal method and timing of embryo biopsy. Thirty-five colleagues have been selected to address these questions on the basis of their experience with PGS, and demonstrated by peer-reviewed publications, presentations at meetings and participation in the discussion. The first group of experts who were asked about 'The Why' comprised fertility experts, the second group of molecular biologists were asked about 'The How' and the third group of embryologists were asked about 'The When'. Furthermore, the geographical distribution of the experts has been taken into account. Thirty have filled in the questionnaire as well as actively participated in the redaction of the current paper.
MAIN RESULTS AND THE ROLE OF CHANCE
The 30 participants were from Europe (Belgium, Germany, Greece, Italy, Netherlands, Spain, UK) and the USA. Array comparative genome hybridization is the most widely used method amongst the participants, but it is slowly being replaced by massive parallel sequencing. Most participants offering PGS 2.0 to their patients prefer blastocyst biopsy. The high efficiency of vitrification of blastocysts has added a layer of complexity to the discussion, and it is not clear whether PGS in combination with vitrification, PGS alone, or vitrification alone, followed by serial thawing and eSET will be the favoured approach. The opinions range from in favour of the introduction of PGS 2.0 for all IVF patients, over the proposal to use PGS as a tool to rank embryos according to their implantation potential, to scepticism towards PGS pending a positive outcome of robust, reliable and large-scale RCTs in distinct patient groups.
LIMITATIONS, REASONS FOR CAUTION
Care was taken to obtain a wide spectrum of views from carefully chosen experts. However, not all invited experts agreed to participate, which explains a lack of geographical coverage in some areas, for example China. This paper is a collation of current practices and opinions, and it was outside the scope of this study to bring a scientific, once-and-for-all solution to the ongoing debate.
WIDER IMPLICATIONS OF THE FINDINGS
This paper is unique in that it brings together opinions on PGS 2.0 from all different perspectives and gives an overview of currently applied technologies as well as potential future developments. It will be a useful reference for fertility specialists with an expertise outside reproductive genetics.
LARGE SCALE DATA
none.
STUDY FUNDING AND COMPETING INTERESTS
No specific funding was obtained to conduct this questionnaire.
Topics: Aneuploidy; Blastocyst; Comparative Genomic Hybridization; Embryo Implantation; Expert Testimony; Female; Genetic Testing; Humans; Pregnancy; Preimplantation Diagnosis
PubMed: 27256483
DOI: 10.1093/molehr/gaw034 -
Biophysical Journal Dec 2018It has long been recognized that mechanical forces underlie mammalian embryonic shape changes. Before gastrulation, the blastocyst embryo undergoes significant shape...
It has long been recognized that mechanical forces underlie mammalian embryonic shape changes. Before gastrulation, the blastocyst embryo undergoes significant shape changes, namely, the blastocyst cavity emerges and expands, and the inner cell mass (ICM) forms and changes in shape. The embryo's inner pressure has been hypothesized to be the driving mechanical input that causes the expansion of the blastocyst cavity and the shape changes of the ICM. However, how the inner pressure and the mechanics of the trophoblast and the ICM change during development is unknown because of the lack of a suitable tool for quantitative characterization. This work presents a laser-assisted magnetic tweezer technique for measuring the inner pressure and Young's modulus of the trophoblast and ICM of the blastocyst-stage mouse embryo. The results quantitatively showed that the inner pressure and Young's modulus of the trophoblast and ICM all increase during progression of mouse blastocysts, providing useful data for understanding how mechanical factors are physiologically integrated with other cues to direct embryo development.
Topics: Animals; Biomechanical Phenomena; Blastocyst; Mice; Pressure; Trophoblasts
PubMed: 30509858
DOI: 10.1016/j.bpj.2018.11.008