Learn More
BACKGROUND The high frequency of chromosomal abnormalities observed in human gametes and embryos is unlike that seen in other mammalian species and is of great clinical significance, leading to high rates of pregnancy loss, and live-born children with aneuploid syndromes. Although much is known concerning the aneuploidy rates of oocytes, cleavage stage(More)
OBJECTIVE To validate and determine the best array-comparative genomic hybridization (aCGH; array-CGH) protocols for preimplantation genetic screening (PGS). DESIGN Embryos had one cell removed as a biopsy specimen and analyzed by one of two array-CGH protocols. Abnormal embryos were reanalyzed by fluorescence in situ hybridization (FISH). SETTING(More)
OBJECTIVE To evaluate a new strategy for comprehensive chromosome screening at the blastocyst stage. DESIGN Clinical research study. SETTING An IVF clinic and a specialist preimplantation genetic diagnosis laboratory. PATIENT(S) Forty-five infertile couples participated in the study. The mean maternal age was 37.7 years, and most couples had at least(More)
Analysis of small numbers of chromosomes using interphase fluorescent in-situ hybridization (FISH) probes has revealed that 50% of human preimplantation embryos contain abnormal cells. Detection of high levels of mosaicism with so few probes has led some researchers to extrapolate that a full analysis of all 23 pairs of chromosomes would reveal that all(More)
Molecular genetic analysis of isolated single cells and other minute DNA samples is limited because there is insufficient DNA to perform more than one independent PCR amplification. One solution to this problem is to first amplify the entire genome, thus providing enough DNA for numerous subsequent PCRs. In this study we have investigated four different(More)
OBJECTIVE To identify and transfer cytogenetically normal embryos after screening all chromosomes of first and second polar bodies (PBs) or trophectoderm samples with the use of comparative genomic hybridization. DESIGN Clinical research study. SETTING In vitro fertilization clinic referring samples to a specialist preimplantation genetic diagnosis(More)
BACKGROUND Recent studies have suggested that biopsy of several trophectoderm (TE) cells from blastocysts followed by comparative genomic hybridization (CGH) analysis might represent an optimal strategy for aneuploidy detection, but few data on accuracy are available. The main question concerns the rate of mosaicism at the blastocyst stage, and to what(More)
Preimplantation genetic diagnosis (PGD) of single gene disorders relies on PCR-based tests performed on single cells (polar bodies or blastomeres). Despite the use of increasingly robust protocols, allele drop-out (ADO; the failure to amplify one of the two alleles in a heterozygous cell) remains a significant problem for diagnosis using single cell PCR. In(More)
BACKGROUND Preimplantation Genetic Diagnosis (PGD) using FISH to analyze up to nine chromosomes to discard chromosomally abnormal embryos has resulted in an increase of pregnancy rates in certain groups of patients. However, the number of chromosomes that can be analyzed is a clear limitation. We evaluate the reliability of using comparative genomic(More)
Despite the clinical importance of aneuploidy, surprisingly little is known concerning its impact during the earliest stages of human development. This study aimed to shed light on the genesis, progression, and survival of different types of chromosome anomaly from the fertilized oocyte through the final stage of preimplantation development (blastocyst).(More)