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Effect of co-incubation of oocytes with a decreasing number of spermatozoa on embryo quality
Shortened exposure of oocytes to spermatozoa has been reported to improve embryo quality. This technique requires extra manipulation of gametes in order to remove oocytes from the spermatozoa. This study presents a fertilization method that does not require additional manipulation and interference of oocytes during fertilization. To determine the benefits of this method, a prospective controlled study using sibling oocytes was conducted. The oocytes of patients were randomly allocated to study and control groups.Polarization microscopy and rescue ICSI
A fraction of standard IVF cycles is afflicted by total fertilization failure. For several years, attempts have been made to develop strategies for rescuing these cycles in order to reduce the physical, psychological and economic burden imposed by an assisted reproduction technology treatment. Rescue ICSI is the approach by which failed fertilized oocytes can be microinjected on day 1 post insemination with the aim of achieving fertilization and thereby preventing cycle cancellation. In a study presented in this issue, Moon and colleagues perfected the rescue ICSI methodology by adopting polarized light microscopy as a tool to identify and treat only failed fertilized oocytes not penetrated by spermatozoa.IVF versus ICSI for the fertilization of in-vitro matured human oocytes
Traditional dogma suggests that intracytoplasmic sperm injection (ICSI) should be performed to ensure successful oocyte fertilization in an in-vitro maturation (IVM) cycle. This study postulated that there would be no difference in the fertilization rate when ICSI was compared with IVF. This hypothesis was tested in a randomized trial of IVF versus ICSI in IVM. A total of 150 immature oocytes were collected in eight cycles of IVM for patients diagnosed with polycystic ovarian syndrome (PCOS). Patients were primed with minimal FSH before transvaginal oocyte aspiration.Temperature gradients in female reproductive tissues
Deep body temperature in mammals is generally but incorrectly regarded as uniform. Alterations of temperature in oviducts and preovulatory Graafian follicles may play a vital role in gamete maturation, fertilization and early embryonic development. At a molecular level, the conformation of regulatory proteins is susceptible to changes in temperature. Deviation from physiological temperature during IVF procedures could thereby exert a profound influence on patterns of gene expression as the embryonic genome unfolds during early cleavage stages and act to generate specific anomalies.
