The Effect of Prolonged Culture of Chromosomally Abnormal Human Embryos on The Rate of Diploid Cells

Evaluating the Plausibility of Euploid Embryos Transfer on Day-5 by Reanalysis of Day-3 Single Aneuploid Embryos: A Case Series

Background

During preimplantation development, single aneuploidies are more commonly tolerated than complex aneuploidies. Some studies have reported that blastocysts with aneuploid karyotypes on Day-3 embryo biopsy can exhibit a normal karyotype on Day-5 rebiopsy, suggesting that single aneuploidies may have a higher likelihood of presenting a normal karyotype on Day-5. The purpose of the current study was to assess the benefit of reanalyzing the karyotypes of Day-3 single aneuploid embryos on Day-5.

Methods

Day-3 and Day-5 biopsies of preimplantation embryos were subjected to array comparative genomic hybridization (aCGH). A proof of concept case series study was conducted involving 13 Day-5 embryos from 4 couples across 3 ART centers, collected between October 2019 and June 2020. Each center provided one normal embryo and 3-4 embryos with single aneuploidy based on Day-3 aCGH results. The karyotype of each Day-5 embryo was compared with its corresponding Day-3 karyotype.

Results

Among the 10 embryos with single aneuploidy on Day-3, 3 (30%) exhibited discordant karyotypes on Day-5, while the remaining 7 single aneuploid embryos and 3 normal embryos maintained the same karyotype from Day-3 to Day-5. None of the Day-3 single aneuploid embryos displayed a normal karyotype on Day-5.

Conclusion

Contrary to previous reports suggesting the potential correction of single aneuploidies in some embryos, the findings of this study did not support such a possibility in the analyzed embryos. Genomic reanalysis of Day-3 single aneuploid embryos on Day-5 does not appear to be a reliable method for identifying euploid embryos suitable for transfer.

Lapatinib Decreases the Preimplantation Aneuploidy Rate of in vitro Fertilized Mouse Embryos without Affecting Completion of Preimplantation Development

One of the major reasons for implantation failure and spontaneous abortion is a high incidence of preimplantation chromosomal aneuploidy. Lapatinib simultaneously inhibits EGFR and HER2, leading to apoptosis. We hypothesized a higher sensitivity for aneuploid cells in preimplantation embryos to lapatinib based on reports of aneuploid cell lines being sensitive to some anticancer drugs. Late 2-cell mouse embryos were treated with lapatinib after determining a nontoxic dose. Morphologies were recorded 24, 48, and 60 hours later. The effect of lapatinib on the aneuploidy rate was evaluated by studying blastocyst cells using FISH. Although the rate of development to 8-cell and morula stage was higher in the control group (p < 0.05), there was no difference in development to the blastocyst stage at the same studied intervals between lapatinib-treated and control groups (p = 0.924). The mean number of cells in morula and blastocyst stages were not different between the groups (p = 0.331 and p = 0.175, respectively). The frequency of aneuploid cells and diploid embryos was, respectively, significantly lower and higher in lapatinib-treated embryos, (p < 0.001). Since lapatinib treatment reduced the aneuploidy rate without impact on the development of mouse preimplantation embryos to the blastocyst stage and number of total cells, lapatinib seems useful for prevention of preimplantation aneuploidy in in vitro fertilization.

Analysis of a Preimplantation Genetic Test for Aneuploidies in Embryos from Colombian Couples: A Report of Cases

BACKGROUND

Assisted reproduction techniques (ARTs) and the preimplantation genetic test for aneuploidies (PGT-A) help couples with fertility problems to achieve a healthy live birth around the world. The aim of this study was to determine the rate of whole chromosomal copy number variations in embryos from couples undergoing ART and PGT-A, associations of chromosomal variations with embryo morphological parameters, and their relationship to maternal age.

METHODS

This study included a retrospective analysis of the number of whole chromosomal copies identified by aCGH in embryos from couples undergoing ART.

RESULTS

Seventy-six embryos from 29 couples using their own gametes were analyzed, of which 25 (32.9%) were chromosomally normal, and 51 (67.1%) were abnormal. Eleven embryos were evaluated from the group of couples with donated gametes, of which 5 (45.4%) embryos were chromosomally normal, and 6 (54.5%) embryos were abnormal. The main aneuploidies observed were trisomy X (7.8%), trisomy 21 (5.9%), trisomy 9 (3.9%), monosomy 11 (3.9%), monosomy 13 (3.9%) and monosomy X (3.9%), and the principal chromosomes affected were 19, X and 13. A significant association was found between the quality of the embryo and the genetic condition: embryos with euploidy and aneuploidy (p=0.046).

CONCLUSION

The rate of aneuploidies from couples with their own gametes was 67.1% (51/76) and from couples with donated eggs and/or sperm was 54.5% (6/11). The quality of the embryo determinated by the morphological parameters was not associated with the embryo genetic status, and also there was no association between maternal age and aneuploidy rate.

Total Antioxidant Capacity; A Potential Biomarker for Non-Invasive Sex Prediction in Culture Medium of Preimplantation Human Embryos

Objective

The presence of a sex related metabolic difference in glucose utilization and, on the other hand, different developmental kinetic rates in human preimplantation embryos, has been previously observed, hawever, the correlation between these two events is unknown. Oxidative stress (OS) induced by higher glucose consumption appears to be a possible cause for the delayed development rate in female embryos. We examined the correlation between glucose consumption and total antioxidant capacity (TAC) concentration in individual embryo culture media for both male and female embryos.

Materials and Methods

In this cross-sectional study, we evaluated high quality embryos from 51 patients that underwent intracytoplasmic sperm injection (ICSI) and preimplantation genetic diagnosis (PGD) at the Royan Institute between December 2014 and September 2017. The embryos were individually cultured in G-2TMmedium droplets at days 3-5 or 48 hours post PGD. We analysed the spent culture media following embryo transfer for total antioxidant capacity (TAC) and any remaining glucose concentrations through fluorometric measurement by chemiluminecence system which indirectly was used for measurement of glucose consumed by embryos.

Results

The results showed that female embryos consumed more glucose which was associated with decreased TAC concentration in their culture medium compared to male embryos. The mean of glucose concentration consumed by the female embryos (30.7 ± 4.7 pmol/embryo/hour) was significantly higher than that of the male embryos (25.3 ± 3.3 pmol/embryo/hour) (P<0.001). There were significantly lower levels of TAC in the surrounding culture medium of female embryos (22.60 ± 0.19 nmol/µl) compared with male embryos (24.74 ± 0.27 nmol/µl, P<0.01).

Conclusion

This finding highlighted the utilization of sex dependent metabolic diversity between preimplantation embryos for non-invasive sex diagnosis and suggests the TAC concentration as a potential noninvasive biomarker for prediction of sex.

Improving preimplantation genetic diagnosis (PGD) reliability by selection of sperm donor with the most informative haplotype

BACKGROUND

The study is aimed to describe a novel strategy that increases the accuracy and reliability of PGD in patients using sperm donation by pre-selecting the donor whose haplotype does not overlap the carrier's one.

METHODS

A panel of 4-9 informative polymorphic markers, flanking the mutation in carriers of autosomal dominant/X-linked disorders, was tested in DNA of sperm donors before PGD. Whenever the lengths of donors' repeats overlapped those of the women, additional donors' DNA samples were analyzed. The donor that demonstrated the minimal overlapping with the patient was selected for IVF.

RESULTS

In 8 out of 17 carriers the markers of the initially chosen donors overlapped the patients' alleles and 2-8 additional sperm donors for each patient were haplotyped. The selection of additional sperm donors increased the number of informative markers and reduced misdiagnosis risk from 6.00% ± 7.48 to 0.48% ±0.68. The PGD results were confirmed and no misdiagnosis was detected.

CONCLUSIONS

Our study demonstrates that pre-selecting a sperm donor whose haplotype has minimal overlapping with the female's haplotype, is critical for reducing the misdiagnosis risk and ensuring a reliable PGD. This strategy may contribute to prevent the transmission of affected IVF-PGD embryos using a simple and economical procedure.

TRIAL REGISTRATION

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. DNA testing of donors was approved by the institutional Helsinki committee (registration number 319-08TLV, 2008). The present study was approved by the institutional Helsinki committee (registration number 0385-13TLV, 2013).