A frozen embryo transfer is not a second choice option. In many clinical situations, it is the superior one with higher implantation rates, better outcomes, and lower risk of ovarian hyperstimulation. At Zoi Fertility, Dr Yashodhara has performed thousands of frozen embryo transfer cycles as part of our comprehensive IVF treatment programme, with over 5,400 cycles completed and a 68% success rate.
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What is Frozen Embryo Transfer (FET)?
In a standard IVF cycle, stimulation produces multiple eggs. Multiple eggs produce multiple embryos. Usually, not all embryos are transferred in the same cycle — either because more embryos exist than should be transferred at once, or because the uterine environment in the retrieval cycle is not optimal for implantation.
Frozen Embryo Transfer (FET) is the process of thawing one or more stored embryos and transferring them to the uterus in a subsequent cycle — when conditions for implantation are independently assessed and confirmed to be optimal.
At Zoi Fertility, vitrification achieves a 95%+ embryo survival rate on thaw. An embryo that survives thaw in good condition carries the same implantation potential as a fresh embryo — and in specific clinical scenarios, a meaningfully better one.
During ovarian stimulation, high oestrogen levels alter the uterine lining in ways that can reduce receptivity. The endometrium — which needs to be in a specific state to accept an embryo — may not reach that state in the same cycle as retrieval.
A frozen transfer decouples retrieval from transfer. In the FET cycle, the uterine lining is prepared independently — either in a natural cycle (using your own hormonal progression) or a medicated cycle (using oestrogen and progesterone to control the timing precisely). Transfer happens only when endometrial thickness and texture confirm the lining is ready.
This is why, in patients with high ovarian response, PCOS, or elevated progesterone at trigger, frozen transfer is the clinically preferred route. It is also why the Freeze All protocol — which cryopreserves all embryos and transfers in a subsequent cycle — produces the results it does.
In simple words, Less Medication and Less Stress. You and your body are not forced to take a lot of medications in the same month. FET Cycles or Frozen Embryo Transfers are more predictable, thereby increasing success chances.
Freezing techniques in IVF ICSI cycles also called the vitrification method have significantly advanced. This also means, on thawing the recovery of the embryos is nearly identical to pre-freezing quality. This results in an increased pregnancy rate, higher live birth rates, fewer miscarriages, and big healthy babies. We get an opportunity to optimize the lining of the uterine cavity before implantation of the embryos.
Like fresh cycles, FET too has one important primary indicator affecting the success rate. That is the age of the mother when the embryos were formed and frozen. Even if you wish to wait many years to transfer the embryos frozen post freezing them, the chances or success factors remain identical. The age at which the embryos were frozen is of paramount importance for considering the success rate. higher the age of the mother when the embryos frozen, less the success chances.
Surplus embryos from your frozen embryo transfer cycle are vitrified and stored. This applies whether you are completing your family now or deferring. The embryos remain available for future transfer cycles, for a second child, or in the event the current transfer does not result in a pregnancy.
Embryo storage is also an option for patients facing medical treatment that may affect fertility such as chemotherapy, radiotherapy, or surgery to the reproductive organs. Freezing embryos before treatment begins preserves the possibility of a biological child after recovery. You may also consider egg freezing as an alternative preservation option.
At Zoi Fertility, stored embryos are held under continuous monitoring with a full chain of custody documentation system compliant with India’s ART Act, 2021 and ICMR guidelines. Your consent governs what happens to stored embryos at every stage. To learn more about frozen embryo transfer or any of our other services including IUI, donor egg IVF, blastocyst transfers, and surrogacy, book a consultation with our team.
