Thawed Embryo Transfer Cycle of In Vitro Fertilization

This is the cycle in which the frozen embryo is thawed and then transferred.
It is very important that the state of the inner membrane has become the state of being able to do implantation.
It is necessary to allow the cycle of the inner membrane and day age of the zygote to sync.
For that there are the following 3methods.

How to decide when to thaw and transfer frozen embryos

Hormone Supplement Cycle circle

Natural Cycle circle

Ovulation Induction Cycle circle

Differences in the Main 3 Methods circle

1. Hormone Supplement Cycle

We will use 2 types of hormones, which will make an “imaginary” ovulation. The inner membrane will be made thick from the estrogen, and the progesterone will create the state of after ovulation.
This is the method that is most often occurred.

Advantages	It is easy to adjust the days. There will be 1 or 2 visits before the embryo transfer decision.
Points to consider	It is necessary to take the hormones everyday. (Even after success of pregnancy, until about 8- 9 weeks.)

2. Natural Cycle

This is the method of transferring the embryo into the endometrium that has thickened by naturally secreted hormones.
We will check imperfections by use of a microscope.
Often we use an HCG injection because it will ensure ovulation. (There is also an effect that will help implantation in HCG.)

Advantages	No hormone drugs are used so it’s natural.
Points to consider	Frequent visits are necessary because we will check your ovulation. It is difficult to help those with irregular menstruation. It is impossible to adjust the date of the embryo transfer.

3. Ovulation Induction Cycle(Clomiphene·FSH/HMG)

His is the method by which we use ovulation induction medicines, and after ovulation has been confirmed then the embryo is transferred.
There are OPU’s done in the same cycle.
Additionally, there are also the thawing and transferring of embryos that had been frozen in the case, where regardless of the planned OPU and ET, there is bad growth of the embryo and there are empty follicles and the ET is cancelled.

Advantages	OPU can be done at the same time. It can often be done for people with thin inner membranes or irregular menstruation, whom are not suitable for the natural cycle.
Points to consider	It is hard to adjust the date. Because we will do ovulation induction, contraception is necessary and in the case of where OPU is not done, then one whole cycle will be wasted. If you plan to do ovulation induction with the next cycle, the ovaries can’t rest and so it is not desirable.

Differences in the Main 3 Methods

The big difference of the abovementioned 3 methods would be if the ET can certainly be done or not.
With Method ② and Method ③, there will be a cancellation if the ovulation day is unknown or if it is late.
Therefore, it is a special feature that there is a high certainty in the sequence of natural ovulation cycle → stimulation cycle → hormone replenishment cycle.
There is no significant difference in the pregnancy rate.

If there are no problems with the implantation environment, determine the embryo transfer date

Before we decide the Embryo Transfer Date, we will measure the thickness of the endometrium by ultrasound test(Also follicle measurement in cases of Natural Cycle· Induction Cycle).
In the case when the inner membrane thickness is less than 7mm there is a chance for a modified increase in the medicine.
In the case where it is judged that there are no problems with the implantation environment, we will decide on the Embryo Transfer date.

	Hormone Supplementation Cycle	Ovulation Induction Cycle	Natural Cycle
Certainty of Transplant	High	Little high	Low
Accommodation	In most cases, it is possible to accommodate	Slightly irregular menstruation, but don’t want to use the medicine for a long time.	Menstruation is in place.
Number of visits until the transfer	1-2 times	3-5 times	3-5 times
Side-effects	Side reactions to the medicine.	Possibility for the development of OHSS (Ovarian Hyper Stimulation Syndrome)	None
Combination and two-step embryo transfer of the SEET Method.	Possible (When the embryo is frozen in the first cycle.)	Possible (When the embryo is frozen in the first cycle.)	Possible (When the embryo is frozen in the first cycle.)
Combination of OPU(Timing· Artificial Insemination)	Impossible	Possible	Possible