Chromosomal Abnormalities and Embryonic Development into the Blastocyst Stage in Mammalian Embryos Derived In Vitro

The recent advance of many technologies in assisted reproduction in experimental and domestic animals has been remarkable. Boerjan et al. [1] described that Assisted Reproductive Technologies (ART) have been introduced 1) to overcome reproductive failures in the humans, 2) to increase the number of offspring from selected females and 3) to reduce generation intervals in l ivestock. However, many technical problems remain, for example, the rates of implantation and p regnancy o f em bryos p roduced by ass i s ted reproductive technologies are not high in cattle [2] and humans [3]. Assurance of cytogenetic quality of the embryos is essential to get higher conception rates. Especially, cytogenetic normality is a very important issue in respect of generation effects in humans. Many reports concerning chromosomal abnormalities have been published [4–10], and some of them have made ment ion of the re la t ion between chromosomal abnormalities and the maturity of oocytes and sperm concentration, however the evaluation of cytogenetic safety in ART is insufficient. It has been shown that chromosome analysis of spare human embryos may have a predictive value for their transferred sibling embryos, and detection of chromosomally normal embryos for transfer is integral for improving the success rate in human In Vitro Fertilization (IVF) [11]. The present review looks at the incidences of chromosomal abnormalities in embryos of several