During an IVF treatment, it may result in one or more embryos. However, it is safer to transfer one or two at a time. If multiple embryos are transferred, the risk of high-order multiple pregnancy increases.
Hence, to decrease this risk two to three embryos are transferred into the uterus and remaining embryos are preserved through cryopreservation for future use.
Image Source: www.invitra.com
FET is a segment of the IVF cycle wherein a cryopreserved embryo resulted from a full IVF cycle is thawed and transferred to a woman’s uterus. This cryopreserved embryo can be from a previous IVF cycle or it may be a donor embryo.
Many times, FET takes place when there are extra embryos after a conventional cycle.
There are two essential sorts of FET-IVF cycles: hormonal support cycles and natural cycles. The most ordinarily performed FET-IVF cycle is a hormonally upheld cycle. This is on the grounds that the day of the move is simpler to control and because hormonal support is required if there are female ovulatory issues.
FET with Hormonal Support
A FET-IVF cycle with hormonal support begins at the end of the previous menstrual cycle, much like a regular IVF cycle. Drug infusions are given to control and close down the regenerative cycle.
When you get your period, an ultrasound and blood work is requested. Once all looks great, estrogen supplementation is begun. This is to help develop a healthy endometrial coating.
Estrogen supplementation is given about 14 days. Another ultrasound and more blood work are requested. The monitoring during a FET-IVF cycle is not exactly as during a traditional IVF cycle.
After two weeks of estrogen support, progesterone support is included. This might be by means of progesterone in oil infusions or conceivably with vaginal suppositories.
The embryo transfer is based on:
- When progesterone supplementation was begun
- At which stage the embryo was cryopreserved
For instance, if the embryo was cryopreserved on Day 5 post-egg-recovery, then the frozen embryo will be transferred on Day 6 after progesterone supplementation begins.
FET Natural Cycle
In a FET natural cycle, medications aren’t utilized to suppress ovulation. Rather, the embryo transfer is performed during natural ovulation occurs.
The timing of embryo transfer is significant.
It must take place at an accurate day after ovulation. As timing is a crucial factor, the cycle is monitored closely at home with ovulation kits or at the clinic with US and blood tests.
When ovulation is diagnosed, progesterone supplementation is begun and embryo transfer is planned.