Mina Alikani

Differences in chromosome susceptibility to aneuploidy and survival to first trimester.

The purpose of this study was to find specific rates of aneuploidy in cleavage-stage embryos compared with first trimester data and to evaluate post-zygotic selection against aneuploidy. A total of 2058 embryos were analysed by flurorescence in-situ hybridization (FISH), and specific aneuploidy rates were obtained for 14 chromosomes. Data from morphologically abnormal embryos could be pooled with data from preimplantation genetic diagnosis (PGD) cycles because it was observed that they had similar rates of aneuploidy; thus, for the purpose of studying aneuploidy they could be, and were, pooled. Specific chromosome aneuploidy rates were not related to morphology or development of the embryos. The average maternal age of patients with aneuploid embryos was significantly higher than the overall analysed population. Monosomy appeared more commonly than trisomy. The chromosomes most frequently involved in aneuploidy were (in order) 22, 16, 21 and 15. When compared with first trimester pregnancy data, aneuploidies detected at cleavage stage seem to die in excess of 90% before reaching first trimester, with the exception of chromosome 16 and gonosomes (76% and 14% respectively). Differences in chromosome-specific aneuploidy rates at first trimester conceptions are probably produced by different chromosome-specific aneuploidy rates at cleavage stage and different survival rates to first trimester.

Chromosome abnormalities in embryos obtained after conventional in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated zygotes produced by intracytoplasmic sperm injection (ICSI) and conventional IVF. DESIGN Embryos were classified by maternal age and morphological and developmental characteristics to avoid bias when comparing chromosome abnormalities in ICSI and IVF embryos. SETTING The Institute for Reproductive Medicine and Science of Saint Barnabas Medical Center, West Orange, New Jersey. PATIENT(S) Seventy-nine couples undergoing IVF and 53 couples undergoing ICSI. INTERVENTION(S) Embryos donated for research were fully biopsied, and their cells were analyzed by fluorescence in situ hybridization with specific probes for chromosomes X, Y, 13, 18, and 21 and some with also a probe for chromosome 16. MAIN OUTCOME MEASURE(S) Embryo chromosome abnormalities. RESULT(S) A total of 245 embryos obtained through conventional IVF and 136 embryos obtained through ICSI were analyzed. There were no statistical differences between the rates of numerical chromosomal abnormalities detected in the IVF (61%) and ICSI (52%) embryos analyzed. Regarding gonosomal aneuploidy, the same rate was found in both ICSI (1%) and IVF groups (2%). CONCLUSION(S) If the parents are chromosomally normal, the results indicate that, at the embryo level and before any embryo selection has occurred in utero, ICSI does not produce more numerical chromosomal abnormalities than conventional IVF.

HUMAN EMBRYO MORPHOLOGY AND DEVELOPMENTAL CAPACITY

Human embryos obtained during therapeutic in vitro fertilization (IVF) are morphologically diverse and display features not common among other mammalian embryos in vitro. Logic dictates and experience concurs that embryo quality assessment must entail more than phenotype alone, but so far and at least in the human, no other evaluation scheme has proven to be more practical or clinically useful. This chapter presents current opinions on the relationship between gross morphology and developmental capacity. An overview of data from a clinical embryology database (EggCyte™) with large numbers of records has also been incorporated.

A high-resolution molecular-based panel of assays for identification and characterization of human embryonic stem cell lines

Meticulous characterization of human embryonic stem cells (hESC) is critical to their eventual use in cell-based therapies, particularly in view of the diverse methods for derivation and maintenance of these cell lines. However, characterization methods are generally not standardized and many currently used assays are subjective, making dependable and direct comparison of cell lines difficult. In order to address this problem, we selected 10 molecular-based high-resolution assays as components of a panel for characterization of hESC. The selection of the assays was primarily based on their quantitative or objective (rather than subjective) nature. We demonstrate the efficacy of this panel by characterizing 4 hESC lines, derived in two different laboratories using different derivation techniques, as pathogen free, genetically stable, and able to differentiate into derivatives of all three germ layers. Our panel expands and refines a characterization panel previously proposed by the International Stem Cell Initiative and is another step toward standardized hESC characterization and quality control, a crucial element of successful hESC research and clinical translation.