What is the survival rate of freezing and thawing?
Not all embryos survive the freezing and thawing process. In a good freezing program, a survival rate of 75-80% should be expected. Therefore, it may be necessary to thaw out several embryos to get two or three good embryos to replace. Damage of embryos does occur as a result of freezing, not during the storage but during the cooling and thawing process.
It is important that both the couple and the clinic to keep in contact with regard their frozen embryos. Most IVF clinics will send an annual reminder letter to patients who have frozen embryos stored.
What options available for couples who have frozen embryos?
There are five choices:
- Continue storage for a further period of time.
- Arrange for embryo transfer treatment cycle before the expiry date.
- Allow embryos to perish by interfering with the thawing process.
- Donate embryos to ethically approved research.
- Donate embryos to infertile couple.
Some couples who completed their familes continue to pay high storage fee for years simply because they are unable to make a decision regarding their frozen embryos. Approximately 10% of the embeyos are donated for research, and 5% are donated to infertile couples and the remainder are disposed of.