Pregnancies achieved after cryopreservation of in vitro and in vivo matured oocytes are not associated with adverse pregnancy outcomes and may represent a novel strategy of fertility preservation.
Emergence of new IVF techniques and massively parallel DNA sequencing provide deep comprehensive genome-wide sequence readout as an end point to screen for and diagnose chromosomal abnormalities and single-gene disorders.
Global metabolomic and amino acid profiles of spent culture media samples from embryos derived from either fresh or vitrified oocytes showed no statistically significant differences.
Evidence indicates that vitrification and warming of unfertilized oocytes followed by fertilization, commonly by intracytoplasmic sperm injection (ICSI), result in subsequent pregnancy rates which are acceptable and this technique should no longer be considered experimental.
Vitrification of prepubertal mouse ovaries did not affect the methylation profile of Snrpn-DMR or their development and fertility potential.
Two vitrification protocols were shown to preserve the morphology and viability of human preantral follicles. After warming and xenografting to nude mice for 1 week, these follicles were able to survive and develop.
Three subsequent washings in certified ultraviolet sterile liquid nitrogen produce an efficient decontamination of vitrification carriers, allowing safe thawing of human specimens.
The author reflects on the findings of Zhao et al. in their article “Effect of 5-aza-2′-deoxycytidine on methylation of the putative imprinted control region of H19 during the in vitro development of vitrified bovine two-cell embryos” and discusses the need for additional research and experience in epigenetics before the new technology can be applied to human IVF and ART.
H19 imprinted control region methylation levels significantly increased in vitrified two-cell embryos and their derived blastocysts; 5-aza-dC significantly reduced H19 imprinted control region methylation and increased H19 expression in blastocysts derived from vitrified embryos.
Blastocyst intrafallopian transfer is a feasible option in cases of repeated difficult ETs, regardless of whether the patient shows cervical adhesions or any type of genital malformations.
We have compared open vs. closed systems for mouse and human blastomere vitrification and conclude that the closed system is more efficient in terms of blastomere survival and division.
Compared with fresh embryo transfers, vitrified day 3 embryo transfer shows no significant differences in obstetrical and neonatal outcomes. Vitrification is a safe method for the cryopreservation of human day 3 embryos.
Solid-surface vitrification resulted in success rates similar to conventional uncontrolled slow freezing inpreserving the integrity and function of prepubertalmouse testicular tissue.
Initial findings suggest that a moderate concentration of the cryoprotectant dimethyl sulfoxide (DMSO) is superior to a high DMSO concentration for both vitrification and slow freezing.
Complete denudation of oocytes before slush nitrogen vitrification does not affect survival rate but is associated with a higher incidence of postthaw meiotic spindle visualization.
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