Do the risks of preimplantation genetic testing for aneuploidy outbalance the benefits?

Die Gynäkologie - Much has been achieved in the field of preimplantation genetic testing for aneuploidy (PGT-A; previously preimplantation genetic screening, PGS) in recent years, particularly...     

Long-read sequencing on the SMRT platform enables efficient haplotype linkage analysis in preimplantation genetic testing for β-thalassemia

Journal of Assisted Reproduction and Genetics - This study aimed to evaluate the value of long-read sequencing for preimplantation haplotype linkage analysis. The genetic material of the three...     

Women’s health providers’ perspectives on preimplantation genetic testing

Research questionWhat are the perspectives of women’s health providers on the use of preimplantation genetic testing (PGT) for common medical disorders?DesignA cross-sectional 15-question online anonymous survey was conducted of women’s health providers specializing in general obstetrics/gynaecology, gynaecologic oncology and infertility at a tertiary care academic institution in Massachusetts, USA. Respondents could answer ‘yes’, ‘no’ or ‘unsure’ to each thematic question.ResultsThe survey was sent to 1060 providers and 240 providers responded (response rate 22.6%). Overall, 93% of respondents supported the use of PGT for the identification of genetic mutations which lead to childhood-onset disease, 83% supported the use of PGT for chromosomal aneuploidy screening, and 76% supported the use of PGT for cancer-related genetic disorders. Only 1.7% of respondents supported the use of PGT for non-disease-related indications, including sex selection and physical traits. Compared with general obstetrics/gynaecology providers, infertility specialists were more supportive of PGT. In total, 22.5% of respondents reported no prior knowledge of PGT.ConclusionsIn a sample of women’s health providers across multiple different obstetrics/gynaecology specialties, there was overall support for the use of PGT for a variety of common indications. Infertility specialists were the most supportive, which may reflect the familiarity that these providers have with this procedure. There was an overwhelmingly non-supportive response for the use of PGT for non-disease-related indications. The percentage of medical professionals working in women’s health without prior knowledge of PGT (22.5%) was higher than expected, identifying the need for more education regarding the availability and potential indications for this procedure.     

Oocyte and embryo quality: do the apoptotic markers have a place in the preimplantation genetic diagnostic?

In Assisted Reproductive Technology (ART), the pregnancy and birth rates following in vitro fertilization (IVF) attempts are still low. Recently, research in the field of ART has explored new oocyte and embryo quality selection criteria such as apoptotic markers. Many studies provided evidence that bad oocyte and embryo quality can be associated with apoptosis. The aim of this review is to summarize our current knowledge on the apoptosis process in oocytes and embryos, and focus on the possibility of using apoptotic markers as a reliable and predictive marker to select competent oocytes and embryos during IFV.     

Birth of a healthy infant after preimplantation genetic diagnosis by sequential blastomere and trophectoderm biopsy for β-thalassemia and HLA genotyping

Background

Preimplantation genetic diagnosis (PGD) is a widely used technique for couples at genetic risk and involves the diagnosis and transfer of unaffected embryos generated through in vitro fertilization (IVF) techniques.

Study design

For those couples who are at risk of transmitting a genetic disease to their offspring, preimplantation embryos can be selected according to their genetic status as well as human leukocyte antigen (HLA) compatibility with the affected child. Stem cells from the resulting baby's umbilical cord blood can be used for transplantation to the affected sibling without graft rejection.

Results

Here we report successful hematopoietic stem cell transplantation (HSCT) after the birth of a healthy infant, who was born after successful PGD testing with both cleavage stage and blastocyst stage biopsy for the purpose of diagnosis of β-thalassemia and HLA compatibility.

Conclusion

The specific feature of this work is not only to have the first successful HSCT achieved in Bulgaria after using preimplantation HLA typing technique, it also demonstrates how to accomplish this success via cross-border collaboration of different units, which makes the application of these sophisticated methods possible in hospitals not having the necessary equipments and expertise.     

Preimplantation genetic testing for aneuploidy in patients with low embryo numbers: benefit or harm?

Journal of Assisted Reproduction and Genetics - We sought to explore the utility of preimplantation genetic testing for aneuploidy (PGT-A) in a poor prognosis group of women with...     

Should every embryo undergo preimplantation genetic testing for aneuploidy? A review of the modern approach to in vitro fertilization

Aneuploid conceptions constitute the majority of pregnancy failures in women of advanced maternal age. The best way to combat age-related decline in fertility is through preimplantation genetic testing for aneuploidy (PGT-A). PGT-A allows for better embryo selection, which improves implantation rates with single embryo transfer and reduces miscarriage rates. Single embryo transfers decrease multiple gestations and adverse pregnancy outcomes such as preterm or low birth weight infants. Advancements in extended embryo culture, blastocyst biopsy techniques, and 24-chromosome aneuploidy screening platforms have made PGT-A safe and accessible for all patients who undergo in vitro fertilization. Improved genomic coverage of new sequencing platforms, such as next-generation sequencing, has increased the identification and diagnosis of mosaicism and partial aneuploidies in preimplantation embryos. Mosaic embryos have decreased viability compared to euploid embryos when transferred, but some mosaic embryos result in normal live births. Whole genome amplification artifacts may contribute to a misdiagnosis of mosaicism, or some mosaic embryos may self-correct to euploid after implantation. For this reason, patients without euploid embryos should be given the option of transferring mosaic embryos after genetic counseling. Further research is needed to characterize which mosaic embryos may be viable.     

Can preimplantation genetic diagnosis overcome recurrent pregnancy failure?

PURPOSE OF REVIEW: Preimplantation genetic diagnosis is widely used for the detection of embryo aneuploidy before implantation, with the aim of avoiding miscarriage or pregnancy termination of an aneuploid fetus. The majority of first trimester miscarriages occur due to chromosomal imbalances. The aim of this review is to assess whether preimplantation genetic diagnosis can help women who suffer from recurrent pregnancy loss. RECENT FINDINGS: Several in-vitro fertilization clinics have employed preimplantation genetic diagnosis in women with recurrent pregnancy loss. Patients were classified into groups according to their age. Preimplantation genetic diagnosis was very successful in treating couples where one of the parents was a carrier of a balanced chromosomal abnormality such as a translocation. Similarly, recurrent pregnancy loss rate was reduced in women more than 35 years in age with a normal karyotype. On the other hand, in younger patients the beneficial effect of this procedure is debatable. In general, women with recurrent pregnancy loss produced more abnormal embryos than control groups. SUMMARY: Preimplantation genetic diagnosis can be beneficial for three major subgroups of patients with recurrent pregnancy loss: couples carrying chromosomal translocations; women more than 35 years of age; women of any age whose previous miscarriages were due to fetal aneuploidy. It is likely that the rate of miscarriage will be further reduced with the new advances in methods of performing preimplantation genetic diagnosis for more chromosomes.     

Preimplantation genetic testing for aneuploidy (PGT-A)—a single-center experience

Journal of Assisted Reproduction and Genetics - The aim of this study was to determine the prevalence and nature of human embryonic aneuploidy based on the preimplantation genetic testing for...