What is Frozen Embryo Transfer (FET)?

Usually, we should be able to create more than few embryos in a standard IVF cycle. If we are doing Freeze All cycle, we will freeze all your embryos. If we transfer 2-3 embryos in the same fresh cycle, we freeze the rest. These embryos which are frozen are then used in the next cycle to achieve pregnancy if the first attempt doesn’t work / in freeze all cycles.

During an IVF ICSI cycle, ovaries are stimulated FSH and LH, this causes estrogen levels to surge/peak at much higher levels than normal. This artificially-induced peak in estrogen causes an increase in progesterone levels in the body. The concern is, there are chances that the progesterone level increase may happen too early, and the endometrial lining may develop too quickly, which will not support the embryos as per their day preparation. This is called desynchronization between an embryo and endometrial lining and it reduces successful implantation of embryos.

How Frozen Embryo Transfer Works With IVF

FET is one of the best ways that we can prevent desynchronization. We do not transfer the embryos, instead delay it until a later cycle, which allows your bodily hormones (stimulation) to normalize before we proceed ahead and this indeed gives you a better chance at pregnancy. After rest, the body recovers in a month’s time from the stress of IVF, and injections taken.  This brings in a normal “milieu” hormonal cycle and thus gives us a chance to increase the pregnancy rate, by thawing and transferring these embryos in this cycle.

Freezing Benefits

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.

Success Rate

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.

Factors Affecting the FET

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.