Preimplantation Genetic Testing: Where We Are Today.

Background: Preimplantation genetic testing (PGT) is widely used today in in-vitro fertilization (IVF) centers over the world for selecting euploid embryos for transfer and to improve clinical outcomes in terms of embryo implantation, clinical pregnancy, and live birth rates.

Methods: We report the current knowledge concerning these procedures and the results from different clinical indications in which PGT is commonly applied.

Results: This paper illustrates different molecular techniques used for this purpose and the clinical significance of the different oocyte and embryo stage (polar bodies, cleavage embryo, and blastocyst) at which it is possible to perform sampling biopsies for PGT.

How 1 h of abstinence improves sperm quality and increases embryo euploidy rate after PGT-A: a study on 106 sibling biopsied blastocysts.

Purpose: The aim of our study was to evaluate the influence of different ejaculatory abstinence time frames (several days versus 1 h) on semen parameters, blastocysts ploidy rate, and clinical results in assisted reproduction cycles on sibling oocytes.

Methods: This is a prospective study including 22 preimplantation genetic testing for aneuploidy (PGT-A) cycles performed between November 2015 and December 2018. Male partners with oligoastenoteratozoospermia produced two semen samples on the day of oocyte retrieval: the first one after several days of abstinence and the second, 1 h after the first one.

Influence of human sperm origin, testicular or ejaculated, on embryo morphokinetic development.

In this retrospective observational study (October 2014 - July 2016), the impact of sperm origin on embryo morphokinetics and on clinical outcomes after intracytoplasmic sperm injection was evaluated. The developmental kinetics of embryos obtained either with testicular sperm (40 cycles; testicular sperm group) or with thawed donor sperm (26 cycles; donor sperm group) was analysed up to day-3 of culture with a time-lapse incubation system. In the testicular sperm group, all patients were affected by nonobstructive azoospermia.

Extent of chromosomal mosaicism influences the clinical outcome of in vitro fertilization treatments.

Objective: To assess whether the extent of chromosomal mosaicism can influence the success rate of IVF treatments.

Design: Prospective study.

Setting: Private genetic and assisted reproduction centers.

Genetic diseases and aneuploidies can be detected with a single blastocyst biopsy: a successful clinical approach.

Study Question: Can simultaneous detection of aneuploidies and genetic diseases or chromosomal aberrations in blastocysts reduce the chance of transferring embryos with low implantation potential, guaranteeing good clinical outcomes?

Summary Answer: The screening for chromosomal aneuploidies revealed that 50.6% of blastocysts diagnosed free of genetic disease or balanced, were aneuploid, therefore avoiding the transfer of blastocysts potentially resulting in implantation failures, miscarriages, or in some cases, in health affected live births.

What Is Known Already: PGD is applied in patients at risk of transmitting genetically inheritable diseases to their offspring.