A. Advantages of embryo freezing -
- 1. It gives you the option of using the embryos in future IVF or ICSI cycles, without
having to go through the risks, expense and inconvenience of using fertility drugs
and undergoing egg collection again.
- 2. If your treatment needs to be cancelled after egg collection, you may still be
able to store your embryos for future use.
- 3. If a woman is facing medical treatment, such as for cancer that may affect her
fertility, (embryo freezing is currently the most effective way for women to preserve
Patient has full control over the future use of their embryos
Before the storage process begins, at ACME fertility clinic & IVF center, we
take an informed consent with following specifications–
- 1. How long you want the embryos to be stored (the standard period is ten years).
- 2. What should happen to your embryos if you or your partner were to die or become
unable to make decisions for yourself.
- 3. Whether the embryos are to be used for your own treatment only, or whether they
can be donated for someone else’s treatment, or used for research.
- 4. Any other conditions you may have for the use of your embryos.
B. Withdrawing consent -
You, your partner or the donor(s) can vary or withdraw consent at any time, before
transfer. It is important to understand that, if this happens, your embryos will
not be used in treatment or research.
C. Main methods
a) Slow programmable freezing -
Machines that freeze biological samples using programmable sequences, or controlled rates,
have been used all over the world for human, animal and cell biology – ‘freezing down’
a sample to better preserve it for eventual thawing, before it is frozen, or cryopreserved,
in liquid nitrogen.
b)Vitrification of oocyte and embryo
The latest technology of cryopreservation means of vitrification has enabled embryologists to freeze oocyte,
embryos at various developmental stages, and sperms obtained from testicular biopsies or epididymis
(in case of azoospermia) with enhanced post thaw survival rates and better outcome.
Freezing is very cost effective, since transferring frozen embryos is much less expensive than starting a
new IVF treatment cycle.
Not all embryos are suitable for freezing. The embryos can be frozen at the pronucleate, early cleavage or blastocyst stage. Overall about 50% of frozen embryos survive the thawing process. Frozen embryos can be thawed and replaced in either natural or artificial cycles. The overall success rates after thawing and replacing frozen embryos is lower than that for fresh embryos. Babies born following embryo freezing have the same risks of abnormalities as those born following IVF/ICSI i.e. the same as those conceived normally.