Importance Of Embryo Assessment
The need to identify the most viable embryo is of fundamental importance. In particular, human IVF clinics have faced this problem because stimulation protocols (1) generate more embryos to choose from and because of the increase in IVF-related multiple births (2, 3). Many methods have been suggested to evaluate embryo viability in both animal models and in human IVF programs. In human IVF clinics, a limiting factor is that these measurements need to be noninvasive and not time consuming....
Advantages and Disadvantages of Polar Body Biopsy
The advantages of polar body biopsy are that, first, it is ethically more acceptable to certain countries (e.g., Malta and Germany) where research and discarding embryos is prohibited. Second, the first and second polar bodies may not be required for further embryonic development and hence the viability of the oocytes and resulting embryos may be equally maintained. One disadvantage of polar body biopsy is that it can only be applied to diagnose maternally inherited diseases. Recombination and...
Contributors
Departments of Obstetrics and Gynecology (Division of Reproductive Medicine), and Cellular and Molecular Medicine University of Ottawa, Canada Molecular and Cellular Biology Program School of Life Sciences Arizona State University Tempe, Arizona, USA Department of OB GYN and Physiology The University of Western Ontario London, Ontario, Canada Parvathi K. Basrur Department of Biomedical Sciences Ontario Veterinary College University of Guelph Guelph, Ontario, Canada Department of Biomedical...
Sex Preselection and Prefertilization Genetics
Certain trends are now emerging in attempts to solve other infertility disorders in human reproduction. Many are linked to genetic issues such as complete spermatogenetic arrest and oocyte aging, while others relate to sex-linked diseases. Table 5.7. Relationship of Congenital Malformation or Chromosomal Defect with Pregnancy Order *Multiple gestations 13 twins, 8 triplets. In humans, there are at least 6000 heritable defects, of which about 370 are known to be X-linked. Because X-linked...
Conclusions
We have outlined the three methods of embryo biopsy in this chapter. Worldwide, the majority of clinics are performing cleavage-stage biopsy at the six- to eight-cell stage, using acid Tyrodes to drill the zona and aspiration to remove the blastomeres (3). There has been an increase in the use of the laser for zona drilling (2, 3), but the cost of the laser is still high, and its use has not been approved in every country. For those performing cleavage-stage biopsy, the decision whether to take...
Metabolic Pathway Activity
SIGNIFICANCE OF METABOLISM IN EMBRYO DEVELOPMENT The early development of the mammalian embryo is directed by its inherent genetic programming and affected by its environment. Both the genetic program and the environment act as stimuli to the early embryo to induce developmental responses, initially in its intracellular biochemical activity, and ultimately in cell division, differentiation, and function. Techniques for manipulating gene expression and development, such as gene transfer,...
Development to the Blastocyst Stage
An interest in culturing human embryos to the blastocyst stage has always existed, in particular as there were always concerns as to the logic of transferring early-cleavage-stage embryos to the uterine environment. Limited data existed that indicated an improved pregnancy rate when placing blastocysts into the uterus. Buster et al. (21) recovered in vivo-developed human blastocysts by uterine lavage and transferred the same blastocysts to achieve a high implantation rate (3 5, 60 ), well above...
