What is a freeze-all cycle?
A fresh embryo transfer occurs in the same IVF cycle in which the embryos were created (a “fresh” cycle). Any embryos remaining following a fresh embryo transfer can be frozen (vitrified) for later use in a “frozen” embryo transfer (FET) cycle. Sometimes, instead of performing a fresh embryo transfer, all embryos may be frozen for later use. This is called a freeze-all cycle.
What are the benefits of a freeze-all cycle?
Freeze-all cycles are performed for many reasons. For one, FET cycles have been associated with higher pregnancy rates in some IVF centers compared to fresh cycle rates. This may be because FET cycles generally (though not always) require less medication than fresh cycles.
Other reasons for freeze-all cycles include a lower risk of ovarian hyperstimulation syndrome (OHSS) associated with FET cycles than with fresh cycles. Moreover, the lower risk of OHSS allows doctors to use higher doses of gonadotropins, which leads to more egg production.
Freeze-all cycles are also advised in cases where gonadotropin stimulation results in too high estrogen or progesterone levels that could impair implantation.
Genetic Screening in Freeze-all Cycles
Freeze-all cycles are also most commonly performed to allow for embryo biopsy as part of a Pre-Implantation Testing (PGT) cycle. PGT can be used to test for chromosome abnormalities (aneuploidy, PGT-A or structural rearrangements, PGT-SR) or for inheritable and lethal genetic mutations, PGT-M.
Both fresh and frozen embryo transfer cycles have enabled many otherwise infertile people the joy of parenthood. The decision to pursue a fresh or FET cycle should be made on a case by case basis, tailored to the specific needs of the individual patient.
Our goal at the Fertility Centers of New England is to help each of our patients achieve a successful, healthy pregnancy. We are here to help answer any questions about the best treatment path for you, please contact us to set up your virtual consultation.