Prematurely condensed chromosomes and meiotic abnormalities in unfertilized human oocytes after ovarian stimulation with and without gonadotropin-releasing hormone agonist

Analysis of Oocyte-Like Cells Differentiated from Porcine Fetal Skin-Derived Stem Cells

“…For example, deficiency in the expression of meiosis maker gene such as DMC1 caused male infertility and decreased female reproductive function [54]. In addition, prematurely condensed chromosomes and meiotic abnormalities are found after in vitro fertilization in unfertilized humans [55]. Future studies on manipulating the system by addition or removal of factors to and from the medium may help to identify factors that are critical for proper meiosis and successful oocyte development.…”

Cytogenetic Analysis ofIn VivoandIn VitroMatured Oocytes Derived from Naturally Cycling and Stimulated Mice

“…Aneuploidy occurs at high rates (up to 52.1%) in mature human oocytes collected from gonadotropin stimulated cycles [Gras et al 1992;Delhanty and Handyside 1995;Wall et al 1996;Racowsky et al 1997;Hodges et al 2002]. Interestingly it has been reported that only 18% of in vitro matured human oocytes have gross meiotic aberrations [Kuliev et al 2003].…”

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

“…It was indicated that superovulation protocols used in IVF did not have an impact on aneuploidy rates in failed fertilized human oocytes [26,47]. However, the higher incidence of meiotic aberrations and prematurely c o n d e ns e d s pe r m c h r o mo s o me s ( P C C ) i n t h e unfertilized population indicated that some retrieved oocytes exhibited incomplete nuclear and cytoplasmic maturation after superovulation [47].…”

“…However, the higher incidence of meiotic aberrations and prematurely c o n d e ns e d s pe r m c h r o mo s o me s ( P C C ) i n t h e unfertilized population indicated that some retrieved oocytes exhibited incomplete nuclear and cytoplasmic maturation after superovulation [47]. Although the mechanism of the formation of second meiotic errors in human oocytes remains open to speculation, the situation with respect to first meiotic-division nondisjunction is somewhat clearer in relation to the maternal age affect [48].…”

“…Although there is no report to our knowledge of chromosomal analysis in morphologically abnormal embryos or developmentally delayed embryos in mice and domestic animals, many results of chromosomal analysis in unfertilized human eggs have been reported [7,26,47,50]. However, it is evident that the incidence of chromosomal anomalies in humans is calculated from abnormal eggs or remaining excessive embryos, which are not transferred to the uterus, while all of the embryos produced by IVF are analyzed in mice and domestic animals.…”