Vitrification (Sperm ,Ovum And Embryo Freezing)
Vitrification is a technology that is used in the embryo and egg freezing process so that they can be stored for later use. It is a technology that has many uses outside of fertility care with egg and embryo freezing, as it allows something with a crystalline structure to be converted into something very smooth. Vitrification is the speedy cooling of liquid medium in the absence of ice crystal formation. The solution forms an formless glass as a result of rapid cooling by direct immersion of the embryos in a polyethylene (PE) straw addicted to liquid nitrogen.
Sperm freezing and storage
Sperm freezing and storage is the procedure whereby sperm cells are frozen to preserve them for future use. Sperm cells have been frozen and thawed successfully for more than 40 years. By using special technology and then keeping sperm in liquid nitrogen & it can be stored for many years while maintaining a reasonable quality
Who may benefit from sperm freezing?
Men who work in high risk occupations, for example
In a typical IVF or ICSI treatment cycle, the woman’s ovaries are stimulated to produce many eggs. Following fertilisation and embryo culture, the best embryos are selected for embryo transfer. For about 50% of couples, there will also be good embryos which are surplus to those required for embryo transfer. These embryos can be frozen at this point for future use.
Embryo freezing (cryopreservation) is a method of preserving the viability of embryos be carefully cooling them to very low temperatures. This is carried out in the laboratory using specialised freezing equipment and the embryos can then be safely stored in liquid nitrogen for extended periods.
Why do we freeze embryos?
Embryo freezing gives you more opportunities for a pregnancy for each hormone stimulation cycle and egg collection. If you do not become pregnant in that first cycle, we can transfer another embryo during a frozen embryo transfer cycle.
How does embryo freezing work?
Embryos can be frozen from Day 2 (four cell stage) to Day 5 (Blastocyst). They are placed in thin plastic straws, sealed at both ends, and labelled with your name and identification number.
They then go into a freezing machine, where the temperature rapidly drops to -150° Celsius. The straws are then placed in goblets, and put into tanks filled with liquid nitrogen, which keeps the temperature at -196° Celsius.
Success rates with frozen embryos
At USHA IVF, many of our births, over many years, have come from the transfer of frozen and thawed embryos. On average the success rate is about 40%, but this mainly depends on the age of the woman’s eggs when the embryos are frozen.
So, if you were to freeze your embryos in your first IVF cycle at the age of 38, and then use them when you’re 42, your fertility chance will be relative to that of a 38-year-old woman rather than a 42-year-old.
What are the benefits of embryo freezing?
The main benefit of embryo freezing is the option to have frozen embryos thawed and transferred to the woman’s uterus in the future without having to undergo stimulation of the ovaries or egg retrieval. It is also possible that there may be enough frozen embryos for more than one subsequent cycle.