Identifying parental and cell-division origins of aneuploidy in the human blastocyst.

Preimplantation genetic testing commonly employs simplistic copy-number analyses to screen for aneuploidy in blastocyst trophectoderm biopsies. Interpreting intermediate copy number alone as evidence of mosaicism has led to suboptimal estimation of its prevalence. Because mosaicism originates from mitotic nondisjunction, utilizing SNP microarray technology to identify the cell-division origins of aneuploidy might provide a more accurate estimation of its prevalence.

Accurate detection and frequency of abnormal ploidy in the human blastocyst.

Objective: To validate the detection of abnormal ploidy in preimplantation embryos and evaluate its frequency in transferrable blastocysts.

Design: A high-throughput genome-wide single nucleotide polymorphism microarray-based preimplantation genetic testing (PGT) platform was validated using multiple positive controls, including cell lines of known haploid and triploid karyotypes and rebiopsies of embryos with initial abnormal ploidy results. This platform was then tested on all trophectoderm biopsies in a single PGT laboratory to calculate the frequency of abnormal ploidy and the parental and cell division origins of error.

A new safe, simple and successful vitrification method for bovine and human blastocysts.

This study examined a new method for vitrification of blastocysts that is safe, simple and easy to learn and use. Current vitrification techniques have shortcomings that include the use of dimethyl sulphoxide, one of the more toxic cryoprotectants, and minute containers that are difficult to handle and are usually open to contamination. Cell handling and loading times are very short, which allows no room for user-associated errors and increases the difficulty of the procedure.

Effect of infertility, maternal age, and number of previous miscarriages on the outcome of preimplantation genetic diagnosis for idiopathic recurrent pregnancy loss.

Objective: To determine whether preimplantation genetic diagnosis (PGD) would decrease spontaneous abortion rates in patients with idiopathic recurrent pregnancy loss (RPL).

Design: Controlled clinical study.

Setting: IVF center and PGD reference laboratory.

Maternal age, morphology, development and chromosome abnormalities in over 6000 cleavage-stage embryos.

Previous studies assessing the relationship between embryo development, maternal age and chromosome abnormalities were either small or analysed mostly embryos not suitable for replacement. The present study includes >6000 embryos, including many suitable for replacement. Embryos with the best morphology and development were 44% euploid in patients younger than 35, decreasing to 21% in patients 41 and older.