FAQ Frozen embryo Transfer
You have obtained an embryo following your in vitro fertilisation. In agreement with your doctor, it may be decided to transfer this embryo in the days following the egg puncture (from day 2 to day 5) or to freeze the embryos to carry out a delayed transfer (a frozen embryo transfer).
Before the frozen embryo transfer
What is embryo transfer?
Embryo transfer during in vitro fertilisation (IVF) involves inserting one or more fertilised embryos into the uterus. There are two types of embryo transfer: fresh embryo transfer and frozen embryo transfer (FET).
What is the difference between frozen and fresh embryo transfer?
Frozen embryo transfer takes place after the embryo has been frozen and then unfrozen. Fresh embryo transfer, on the other hand, takes place directly after embryo culture.
What is the procedure if I have frozen embryos?
For a frozen embryo transfer, there is an endometrial preparation phase (in a substituted, stimulated or natural cycle) and then the gynaecologist decides on the best day to place the embryo.
What is the procedure for a frozen embryo transfer (FET)?
For a Frozen Embryo Transfer (FET) protocol, the procedure consists of preparing the endometrium (thickening the tissue of the uterus that will receive the embryo and into which an embryo will be deposited) and then choosing the appropriate day for transferring the embryo(s).
What is frozen embryo transfer on a spontaneous (or natural) cycle?
For a transfer during a spontaneous cycle, the gynaecologist will monitor the cycle without treatment and use blood tests and ultrasound scans to determine the best time to place the embryo back in the uterus.
How soon after my period can I have a frozen embryo transferred?
It depends on the treatment. The length of a treatment and its composition vary according to the patient.
How long does the embryo transfer take place after the ultrasound or on the 1st day of menstruation?
This depends on the stage of the embryo. For example, embryo implantation occurs 5 days after the introduction of progesterone for an embryo frozen on day 5.
How long after the puncture does the embryo transfer take place?
Embryo implantation can be carried out between 2 and 5 days after the puncture, depending on the decision taken by the clinical and biological team.
During frozen embryo transfer
What size does the endometrium need to be to implant an embryo?
To prepare for an embryo transfer, the endometrium must be approximately 7 to 8 mm thick.
How is an embryo transfer carried out?
Whether fresh or frozen, embryo transfer is a painless procedure. It is usually carried out under ultrasound guidance. The gynaecologist places the embryo(s) in the uterus using a catheter.
At what point in the protocol does the embryo transfer take place?
This depends on the decision of your assisted reproduction centre. The embryo transfer can take place on D2, D3 or D5 after IVF (in vitro fertilisation).
How many days after ovulation is induced are the embryos replaced?
There is a waiting period of between 2 and 5 days between the onset of ovulation and the replacement of the embryo(s).
What level of progesterone is needed for an embryo transfer?
Frozen embryo transfer must take place within the correct implantation window (the progesterone-modified endometrium must be in phase with the embryo). If the progesterone is added too early, the transfer may be compromised.
After frozen embryo transfer
What are the signs of embryonic implantation?
It is not possible to identify the signs of embryonic implantation because the treatments given, such as progesterone, can simulate the effects of pregnancy.
What precautions should be taken after an embryo transfer?
After an embryo transfer, it is important to continue taking the medication prescribed by your doctor. In addition, you can lead a normal life as there are no particular restrictions.
When should blood be taken following blastocyst transfer?
The sample is taken approximately 10 days after a blastocyst transfer.
How long after a puncture or embryo transfer can I have sexual intercourse?
It depends on your doctor's recommendations, but generally as soon as you feel ready.
How long after a frozen embryo transfer can I have sexual intercourse?
After a transfer, sexual activity can be restarted within 24 hours. It has been shown that normal activity has no impact on the chances of success.
Do I have to take time off work after an embryo transfer puncture?
This depends on the team, from 24 hours (just before the puncture) to the time of transfer.
When does implantation take place during a D5 blastocyst transfer?
Nidation occurs between 2 and 7 days after the transfer of a D5 blastocyst.
How long after the transfer does implantation take place?
It all depends on how many days old the embryo is at the time of transfer. For example, in the case of a blastocyst (5-day-old embryo), implantation occurs around 2 days later, on the 7th day.
How long after an embryo transfer can I go to the toilet?
After embryo implantation, you can go straight to the toilet and resume your normal life. It has been shown that normal activity has no impact on the chances of success.
Embryo freezing techniques
What is vitrification?
Vitrification of oocytes and embryos is an ultra-rapid freezing technique that allows embryos to be preserved more effectively.
How long does the embryo cultivation period last after defrosting?
The embryos are unfrozen on the day of the frozen embryo transfer, just a few hours beforehand.
What is the difference between vitrification and freezing?
These are 2 different freezing techniques: vitrification is quick freezing.
Why freeze embryos?
Embryos can be frozen either after a fresh transfer (supernumerary embryo freezing) or with a view to a delayed transfer. This allows embryo transfers to be carried out without the need to stimulate and puncture oocytes again.
What is vitrified oocyte reheating?
Reheating vitrified oocytes involves thawing oocytes that have been vitrified (i.e. frozen using a rapid technique).
Or more questions about...