Confirmation and pathogenicity of small copy number variations incidentally detected via a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy platform.

Objective: To evaluate the technical accuracy, inheritance, and pathogenicity of small copy number variants (CNVs) detected by a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy (PGT-A) platform.

Design: Retrospective observational study performed between 2020 and 2022.

Setting: Clinic.

Evidence-based management of preimplantation chromosomal mosaicism: lessons from the clinic.

Mosaic results obtained through preimplantation genetic testing for aneuploidy pose ongoing challenges to clinical practice. Thorough genetic counseling for patients considering mosaic embryo transfer is consistently recommended by many best-practice statements, and providers are charged with the task of assessing and explaining potential prenatal, neonatal, and long-term risks. However, an increasing amount of outcome data from transferred embryos with mosaic results do not show any evidence of increased risk to ongoing pregnancies or newborns.

Transfer of embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M): experience of two high-volume fertility clinics.

Purpose: To assess the experiences of two large fertility clinics in which embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M) were transferred upon patient request, in order to explore the nature of the conditions for which these requests have been made and review ethical considerations.

Methods: Retrospective review of previous embryo transfers at the NYU Langone Fertility Center and ORM Fertility was performed. Embryo transfers prior to May 2019 in which embryo biopsy and PGT-M occurred were reviewed, and transferred embryos that were positive for a monogenic disorder (excluding autosomal recessive carriers) were identified.

Optimal euploid embryo transfer strategy, fresh versus frozen, after preimplantation genetic screening with next generation sequencing: a randomized controlled trial.

Objective: To compare two commonly used protocols (fresh vs. vitrified) used to transfer euploid blastocysts after IVF with preimplantation genetic screening.

Design: Randomized controlled trial.

Counselling considerations for chromosomal mosaicism detected by preimplantation genetic screening.

The evolution of preimplantation genetic screening (PGS) for aneuploidy to blastocyst biopsy and more sensitive 24-chromosome screening techniques has resulted in a new diagnostic category of PGS results: those classified as mosaic. This diagnosis presents significant challenges for clinicians in developing policies regarding transfer and storage of such embryos, as well as in providing genetic counselling for patients prior to and following PGS. Given the high frequency of mosaic PGS results and the wide range of possible associated outcomes, there is an urgent need to understand how to appropriately counsel patients regarding such embryos.

Use of suboptimal sperm increases the risk of aneuploidy of the sex chromosomes in preimplantation blastocyst embryos.

Objective: To compare autosomal and sex chromosome aneuploidy rates of embryos derived from sperm with abnormal and normal parameters.

Design: Retrospective cohort study.

Setting: Assisted reproduction center.