To transfer or not to transfer: the dilemma of mosaic embryos - a narrative review.

A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both).

ESHRE PGT Consortium data collection XXI: PGT analyses in 2018.

Study Question: What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years?

Summary Answer: The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail.

What Is Known Already: Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published.

Telomeres and oocyte maturation rate are not reduced by COVID-19 except in severe cases.

In Brief: COVID-19 does not affect the telomeres or fertility outcomes in mild cases. However, in women with severe symptoms, telomeres of granulosa cells are shorter, and the oocyte maturation rate is decreased.

Abstract: The coronavirus SARS-CoV-2 causes COVID-19 disease and affects primarily the lungs and also other organs, causing accelerated cell aging.

Association between clinical and IVF laboratory parameters and miscarriage after single euploid embryo transfers.

Background: The goal of this study was to investigate which factors, excluding embryo aneuploidies, are associated with miscarriage in patients who have undergone a single euploid blastocyst transfer.

Methods: Retrospective, observational and multicenter study with 2832 patients undergoing preimplantational genetic testing for aneuploidies (PGT-A) due to repeated implantation failure, recurrent pregnancy loss, advanced maternal age or severe male factor were transferred one single euploid embryo.

Results: One of the main findings was a significant relationship between body mass index (BMI) and miscarriage rates (13.

Magnetic-Activated Cell Sorting (MACS): A Useful Sperm-Selection Technique in Cases of High Levels of Sperm DNA Fragmentation.

Magnetic-activated cell sorting (MACS) can be used to separate apoptotic sperm with high proportions of fragmented DNA from the rest, thus improving the overall quality of the seminal sample. Therefore, the aim of this retrospective study was to investigate the efficiency of the MACS technique to increase reproductive outcomes in patients with high levels of sperm DNA fragmentation (SDF) undergoing intracytoplasmic sperm-injection (ICSI) cycles. In this study, we analyzed a total of 724 assisted-reproduction-technique (ART) cycles that were divided into two groups: the study group ( = 366) in which the MACS selection technique was performed after density-gradient centrifugation (DGC), and the control group ( = 358) in which only DGC was used for sperm selection.