Recent research has shown evidence that transferring “frozen embryos” rather than “fresh embryos” can result in higher chances of success with IVF or ICSI treatment. This strategy is sometimes referred to as the “freeze all” or “deferred embryo transfer” approach. A frozen embryo transfer is known an FET.
The groups of patients are most likely to benefit from this approach:
- Patients who have had repeated IVF or recurrent implantation failure
- Patients with polycystic ovary syndrome (PCOS)
- Patients where an agonist trigger is used
- Patients where blastocysts develop more slowly
- Patients in whom progesterone levels rise in advance of ovulation
- In patients of advanced maternal age
It appears the reason for the better success rates, relate to the endometrium (lining of the womb) being in a better state to accept embryos for implantation when not having drugs to stimulate egg production. It would appear that the high doses of medication used to stimulate the production of eggs for IVF or ICSI can lead to endometrial dysynchrony (being out of phase) where the development of the embryo and endometrium are not at the same stage for implantation.
Using this strategy will result in a delay in treatment as eggs have to be collected and then frozen as embryos (or blastocysts), and then waiting before transferring them in another cycle. However, will be worth the wait if success rates are higher.
In order for this strategy to be successful your treatment centre must have excellent proven success rates with frozen embryos. If you would like to discuss this further with one of our fertility consultants at BCRM please contact us.