The influence of balanced complex chromosomal rearrangements on preimplantation embryonic development potential and molecular karyotype.
ABSTRACT: BACKGROUND:Balanced complex chromosome rearrangements (BCCR) are balanced chromosomal structural aberrations that involve two or more chromosomes and at least three breakpoints. It is very rare in the population. The objective is to explore the difference of influence of three types of BCCR on early embryonic development and molecular karyotype. RESULTS:Twelve couples were recruited including four couples of three-way rearrangements carriers (group A), three couples of double two-way translocations carriers (group B) and five couples of exceptional CCR carriers (group C). A total of 243 oocytes were retrievedin the seventeen preimplantation genetic testing (PGT) cycles, and 207 of these were available for fertilization. After intracytoplasmic sperm injection, 181oocytes normally fertilized. The rates of embryos forming on day3 in three groups were 87.88, 97.78 and77.14%, which was significantly different (P?=?0.01). Compared with group B, the rate of embryo formation was statistically significantly lower in group C (P?=?0.01). Furthermore, the rates of high-quality blastocysts in three group were 14.71, 48.15 and 62.96%, respectively, which was significantly different (P?=?0.00). Compared with group B andC, the rate of high-quality blastocysts in group A was statistically significantly lower (P?=?0.00;P?=?0.00). Comprehensive chromosome analysis was performed on 83 embryos, including 75 trophectodermcellsand 8 blastomeres. Except 7 embryos failed to amplify, 9.01%embryos were diagnosed as euploidy, and 90.91% were diagnosed as abnormal. As for group A, the euploid embryo rate was 10.71%and the abnormal embryo rate was 89.29%. In group B,the euploid embryo rate was 3.85%, the abnormal embryo rate was 96.15%. The euploid embryo rate was 13.04%, the abnormal embryo rate was 86.96% in group C. There were no significant differences among the three groups (P?=?0.55). CONCLUSIONS:The lowest rate of high quality blastocysts has been for three-way rearrangements and the lowest rate of euploidy has been for double two-way translocations, although no significant difference. Different types of BCCR maybe have little effect on the embryonic molecular karyotype. The difference of influence of BCCR on early embryonic developmentandmolecular karyotypeshould be further studied.
Project description:PURPOSE:In this study, we tested the hypothesis that, in PGT-A cycles, decreased semen quality is associated with increased rates of mosaic blastocysts. METHODS:In a retrospective analysis, three hundred and forty PGT-A cycles are divided into study groups according to semen quality. Cycles were initially divided into two groups, discerning couples with absence of male factor of infertility (non-male factor: NMF; N?=?146 cycles) from couples with a male factor of infertility (MF; N?=?173 cycles). Couples with severe male factor (SMF) infertility (n?=?22) were assessed separately. Embryos were cultured to the blastocyst stage and chromosomally assessed by array comparative genomic hybridization (aCGH). The study did not involve specific interventions. RESULTS:The reproductive outcome of MF and NMF groups did not indicate statistically significant differences. However, while no differences were found between MF and NMF groups in terms of euploid or aneuploid blastocysts rates, a significantly higher rate of mosaic blastocysts was observed in the MF group (3.6% vs. 0.5%, respectively; P?=?0.03). A similar pattern of results was observed in the SMF group when compared with those of the other PGT-A cycles taken together (no SMF). In particular, a significantly higher rate of mosaic blastocysts was observed in the SMF group (7.7% and 1.8%, respectively; P?=?0.008). CONCLUSIONS:The study outcome strongly suggests that compromised semen quality is associated with increased rates of mosaic blastocysts analysed in PGT-A cycles. Sperm assessment appears therefore as an important factor in the determination of embryo development and for a more precise prognostic assessment of PGT-A cases.
Project description:BACKGROUND:Previous studies from this as well as other research groups suggested that non-invasive chromosome screening (NICS) with embryo culture medium can be used to identify chromosomal ploidy and chromosomal abnormalities. We here report a series of clinical cases utilizing the technology. METHODS:A total of 45 couples underwent in vitro fertilisation during a period between February 2016 and February 2017. Karyotyping revealed normal chromosomes in both partners in 23 couples, and chromosomal rearrangements in at least one partner in 22 couples. Intracytoplasmic sperm injection (ICSI) was used for fertilization. NICS was carried out using embryo culture medium at the blastocyst stage via multiple annealing and looping-based amplification cycles, whole-genome amplification and next-generation sequencing. RESULTS:A total of 413 embryos were obtained; 170 blastocysts were subjected to NICS. The screening showed euploidy in 79 embryos, aneuploidy in 52 embryos, and mosaic ploidy for 33 embryos. The rate of euploidy was comparable in couples with normal karyotype (50.7%; 38/75) vs. chromosomal rearrangement (43.2%; 41/95). A total of 52 euploid embryos (50 oocyte retrieval cycles) were transferred in 43 women. Biochemical pregnancy rate was 72.0% (36/50). Clinical pregnancy rate was 58.0% (29/50). The rate of spontaneous miscarriage was 3/29 (none with chromosomal aneuploidy). A total of 27 healthy babies were delivered. CONCLUSIONS:NICS could identify embryo chromosomal abnormalities in couples either with or without chromosomal rearrangement, with satisfying clinical outcomes.
Project description:PURPOSE:This paper aims to investigate the efficacy of IVF with preimplantation genetic testing for aneuploidy (PGT-A), using only best-scoring blastocysts from young (??35 years) infertile patients undergoing single blastocyst frozen embryo transfers (FET). METHOD:In this randomized controlled trial (RCT) registered 29 March 2017, 302 infertile patient-couples eligible to participate underwent autologous ICSI blastocyst freeze-all cycles. Two-hundred and twenty patient-couples satisfied the inclusion criteria (i.e., female age???35 years, two-day 5 ??2BB blastocysts) and were randomized to either the PGT-A (PGT-A group, n?=?109) selection arm or morphology score (morphology group, n?=?111) selection arm. In both arms, the highest ranking (by morphological score) blastocysts were selected for FET. RESULTS:Of the 109 best-scoring blastocysts that underwent PGT-A, 80 were predicted to be euploid (73.4%) and were transferred in FET (euploid subgroup). There was no statistical difference in LB rate between the euploid subgroup and morphology group (56.3% vs 58.6%, odds ratio 0.91 (95% CI 0.51-1.63), p?=?0.750). In a multiple logistic regression, the transfer of euploid blastocysts was not found to be a significant predictor of LB when adjusting for female age, infertility duration, antral follicle count, and blastocyst quality, with the independent odds expressed as 0.91 (95% CI 0.50-1.66, p?=?0.760). CONCLUSION:In young (??35 years) infertile patients with at least two ??2BB blastocysts, PGT-A blastocyst selection does not result in an enhanced LB rate, with the evidence suggesting that the effectivity of PGT-A may be limited by the effectivity of TE biopsy. TRIAL REGISTRATION:ClinicalTrials.gov ID: NCT03095053.
Project description:The purpose of this study was to investigate the chromosomal constitution and the developmental potential of intracytoplasmic sperm injection (ICSI) deriving embryos displaying a single pronucleus at the zygote stage.Eighty-eight embryos from single pronucleus (1PN) two polar bodies (2PB) ICSI zygotes from 64 preimplantational genetic screening (PGS) cycles (October 2012-December 2014), were retrospectively analyzed. Zygotes were cultured in a time-lapse incubator. Embryo biopsy was performed on day 3 and genetic analysis approached by array comparative genomic hybridization.Chromosomal analysis revealed that 17% (15/88) of embryos derived from 1PN 2PB zygotes were diagnosed as euploid. After blastomere biopsy at day 3, the blastocyst rate at day 5 was 3.4% (3/88). Only 2.3% (2/88) euploid blastocysts were obtained. In two couples and after counseling and patient agreement, the transfer of a euploid blastocyst from a 1PN 2PB ICSI zygote was performed resulting in the birth of a healthy child.These results open the possibility to consider embryos coming from 1PN 2PB ICSI zygotes for transfer when no other embryos from 2PN 2PB ICSI zygotes are available and if a PGS diagnosis of euploidy is obtained. Confirmation of biparental inheritance is strongly recommended.
Project description:PURPOSE:The aim of the study is to investigate how blastocyst contraction behaviour affects the reproductive competence in high-quality euploid embryos. METHODS:Eight hundred ninety-six high-quality blastocysts derived from 190 patients (mean age 38.05 (SD = 2.9) years) who underwent preimplantation genetic testing for aneuploidies (PGT-A) from January 2016 to October 2017 were included in this study. PGT-A results were reported as euploid or aneuploid. Aneuploid embryos were sub-classified into three categories: monosomy, trisomy and complex aneuploid. Retrospective studies of time-lapse monitoring (TLM) of those embryos were analysed and reproductive outcome of transferred embryos was collected. RESULTS:A total of 234/896 were euploid (26.1%) whilst 662/896 (73.9%) blastocysts were proven to be aneuploid from which 116 (17.6%) presented monosomies, 136 (20.5%) trisomies and 410 (61.9%) were complex aneuploid. The most frequent chromosomal complements were trisomies affecting chromosome 21 and monosomies involving chromosomes 16 and 22. Data analysis showed a statistical difference in the number of contractions being reported greater in aneuploid when compared to euploid embryos (0.6 vs 1.57; p < 0.001). Analysis of the aneuploid embryos showed that monosomies present less number of contractions when compared to embryos affected with trisomies or complex aneuploidies (1.23 vs 1.53 and 1.40; p < 0.05). No difference was observed when comparing the latter two groups. Euploid embryos presenting at least one contraction resulted in lower implantation and clinical pregnancy rates when compared to blastocysts that do not display this event (47.6 vs 78.5% and 40.0 vs 59.0% respectively). CONCLUSIONS:Most aneuploid blastocysts diagnosed by PGT-A have complex aneuploidies, showing that aneuploid embryos can develop after genomic activation and reaching high morphological scores. It becomes clear that embryo contraction, despite being a physiological feature during blastulation, is conditioned by the ploidy status of the embryo. Furthermore, the presence of contractions may compromise implantation rates.
Project description:This was a retrospective comparison study of SNP-based preimplantation genetic screening (SNP-PGS) and FISH-based preimplantation genetic diagnosis (FISH-PGD) for 575 couples in total with chromosome translocations, including 169 couples treated by SNP-PGS between October 2011 and August 2012, and 406 couples treated by FISH- PGD between January 2005 and October 2011. In total, 773 blastocysts obtained from 169 couples were biopsied and frozen, embryo transfer was carried out on the balanced embryos. The PGS results and pregnancy outcomes were compared with those of FISH-PGD for 406 translocation carriers with 3,968 embryos biopsied on day 3. Of the 773 biopsied blastocysts, reliable SNP-PGS results were obtained for 717 (92.76%). For Robertsonian translocation carriers, the rate of normal/balanced embryos, embryos with translocation-related abnormalities, and embryos with abnormalities unrelated to a translocation were 57.80%, 23.39% and 18.81%, respectively. In reciprocal translocation carriers, the rate of normal/balanced embryos, embryos with translocation-related abnormalities and embryos with abnormalities unrelated to translocation were 35.47%, 52.10% and 12.42%, respectively. There was no significant differences in patient age, basal endocrine level and the average number of retrieved oocytes and good quality day 3 embryos before biopsy in the SNP-PGS group compared with the FISH-PGD group. The number of embryos biopsied in the FISH-PGD group was higher than in the SNP-PGS group. However, the pregnancy rate with successful delivery per oocyte retrieval and the implantation rate were both lower in the FISH-PGD group than in the SNP-PGS group. The spontaneous abortion rate was higher in the FISH-PGD group than in the SNP-PGS group. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from trophectoderm cells.
Project description:Human embryogenesis frequently coinciding with cell division mistakes contributing to pervasive embryonic aneuploidy/mosaicism. While embryo self-correction was elegantly demonstrated in mouse models, human studies are lacking. Here we are witness to human embryos ability to eliminate/expel abnormal blastomeres as cell debris/fragments. Each blastocyst and its corresponding debris were separated and underwent whole genome amplification. Seven of the 11 pairs of blastocysts and their corresponding cell debris/fragments revealed discordant results. Of the 9 euploid blastocysts, four showed euploid debris, while in the others, the debris were aneuploid. In the remaining pairs, the debris showed additional aneuploidy to those presented by their corresponding blastocyst. The observed ability of human embryos to self-correction doubts many invasive and non-invasive preimplantation testing for aneuploidy at the blastocyst stage, rendering high rate of false positive (discarding “good” embryos) by identifying the cell-free DNA originated from the expelled cell debris, as aneuploidy/mosaic blastocyst.
Project description:We investigated the incidence of aneuploidy in embryos from couples carrying monogenic diseases and the effect of embryo aneuploidy screening on the monogenic disease preimplantation genetic diagnosis (PGD). From November 2014 to April 2017, 36 couples carrying monogenic diseases were enrolled. The karyomap gene chip technique was used to analyze the blastocysts from the subjects and select normal embryos for transfer. A total of 43 single-gene PGD cycles were performed. A total of 687 eggs were obtained and 186 blastocysts were biopsed. After analysis via karyomap chip, 175 blastocysts received diagnostic results. In our monogenic disease PGD, 66.8% (117/175) of the embryos were diagnosed as normal or non-pathogenic (silent carriers), and 33.2% (58/175) of the embryos were diagnosed as abnormal or pathogenic. For preimplantation genetic screening (PGS), the aneuploidy rate of embryos was 22.9% (40/175). Among embryos diagnosed as normal for monogenic diseases, 26.5% (31/117) of the embryos were aneuploid and could not be transferred. Thus, approximately 1/4 of normal or non-pathogenic blastocysts diagnosed based on monogenic disease PGD were aneuploid, indicating the necessity and importance of embryo aneuploidy screening during PGD for monogenic diseases.
Project description:Uniparental disomy (UPD) has been shown to be rare in human normal blastocysts, but its frequency in discarded morphologically abnormal embryos and its relevance to embryonic self-correction of aneuploid remains unknown. The aim of this study was to detect UPD in discarded morphologically abnormal embryos. Both discarded morphologically abnormal embryos, including zero-pronuclear zygotes (0PN), one-pronuclear zygotes (1PN), three-pronuclear zygotes (3PN) and 2PN embryos scored as low development potential were cultured into blastocysts then underwent trophectoderm biopsy. Genome-wide UPD screening of the trophectoderm of 241 discarded morphologically abnormal embryo sourced blastocysts showed that UPD occurred in nine embryos. Five embryos exhibited UPDs with euploid chromosomes, and four displayed UPDs with chromosomal aneuploid. The percentage of UPDs among the morphologically abnormal sourced blastocysts was 3.73%, which is significant higher than the percentage observed in normal blastocysts. The frequency of UPD in 3PN-sourced blastocysts was 7.69%, which is significantly higher than that in normal blastocysts. This study provides the first systematic genome-wide profile of UPD in discarded morphologically abnormal embryos. Our results indicated that UPD may be a common phenomenon in discarded morphologically abnormal embryos and may be relevant to human embryonic self-correction.
Project description:<h4>Purpose</h4>The purpose of this study is to summarize the clinical outcomes of apparently balanced chromosome rearrangement (ABCR) carriers in preimplantation genetic testing (PGT) cycles by next-generation sequencing following microdissecting junction region (MicroSeq) to distinguish non-carrier embryos from balanced carriers.<h4>Methods</h4>A retrospective study of 762 ABCR carrier couples who requested PGT for structural rearrangements combined with MicroSeq at the Reproductive and Genetic Hospital of CITIC-Xiangya was conducted between October 2014 and October 2019.<h4>Results</h4>Trophectoderm biopsy was performed in 4122 blastocysts derived from 917 PGT-SR cycles and 3781 blastocysts were detected. Among the 3781 blastocysts diagnosed, 1433 (37.9%, 1433/3781) were balanced, of which 739 blastocysts were carriers (51.57%, 739/1433) and 694 blastocysts were normal (48.43%, 694/1433). Approximately 26.39% of cycles had both carrier and normal embryo transfer, and the average number of biopsied blastocysts was 6.7. In the cumulative 223 biopsied cycles with normal embryo transfer, all couples chose to transfer the normal embryos. In the 225 cycles with only carrier embryos, the couples chose to transfer the carrier embryos in 169/225 (75.11%) cycles. A total of 732 frozen embryo transfer cycles were performed, resulting in 502 clinical pregnancies. Cumulatively, 326 babies were born; all of these babies were healthy and free of any developmental issues.<h4>Conclusion</h4>Our study provides the first evaluation of the clinical outcomes of a large sample with ABCR carrier couples undergoing the MicroSeq-PGT technique and reveals its powerful ability to distinguish between carrier and non-carrier balanced embryos.