High survival rate of metaphase II human oocytes after first polar body biopsy and vitrification: determining the effect of previtrification conditions

Comparison outcome of fresh and vitrified donor oocytes in an egg-sharing donation program

“…In total, 192 of 210 (91.4%) oocytes survived after vitrification. We found that there was no statistically significant difference in fertilization rates (84.4% vs. 86.6%) between the vitrified and fresh oocytes, which is similar to what other researchers have obtained with other vitrification systems (13,(30)(31)(32)(33)(34)(35). This suggests that vitrified oocytes retain their morphologic and functional integrity.…”

Application of intra- and extracellular sugars and dimethylsulfoxide to human oocyte cryopreservation

“…Earlier studies using mouse oocytes and zygotes also showed that microinjected trehalose at its effective concentrations was non-toxic and quickly eliminated during embryonic development [15,29]. In recent years, several studies reported excellent survival rates after vitrification of human oocytes [6,9,[32][33][34]. These results are encouraging; yet the vitrification procedure used in these studies requires direct contact with LN2, and thus is of concern due to contamination risk.…”

Intra-age, intercenter, and intercycle differences in chromosome abnormalities in oocytes

“…In addition to interage differences, we observed substantial variation between centers. This variation could be due to the use of different stimulation protocols (21,52,53) and/or other technical differences in the IVF procedure (54), or in the FISH technique, as discussed previously. In absolute number of euploid eggs in comparison to the mean number of euploid eggs per each age group and center, the variability does not appear to be as big, with 31.4% of patients having AE2 or more euploid eggs than the average.…”

“…An alternative to freezing ever increasing numbers of oocytes with increasing maternal age to compensate for those that are expected to be chromosomally abnormal is to test the oocytes by first PB analysis to determine how many euploid oocytes would be available (27,54). The study of Keskintepe et al (54) showed that first PB removal before egg preservation is safe and does not interfere with egg survival.…”

“…The study of Keskintepe et al (54) showed that first PB removal before egg preservation is safe and does not interfere with egg survival. An ongoing clinical randomized study organized by the European Society of Human Reproduction and Embryology (ESHRE) PGD consortium will determine whether PB biopsy and array CGH can improve pregnancy results.…”