BLASTOCYST TRANSFER

Important messages:

–       Blastocyst transfer is a method that should be preferred in certain groups of patients

–       It should not be applied to all cases

–       The day on which the embryo will be placed into the uterus should be decided individually, according to the development of the uterine lining and the development of the embryo

–       It is not correct to perform blastocyst transfer on day 5–6 or embryo transfer on day 3–2 for all cases

–       If the case has previous unsuccessful attempts, the day of transfer should be decided according to these details and the laboratory follow-up during the active treatment process

–       Laboratory quality is essential in deciding the most appropriate day for transfer

–       All these details should be shared with the couple before transfer so that they can proceed to transfer in an informed way and with peace of mind

Blastocyst-stage embryos are obtained in the laboratory on the 5th or 6th day after fertilization.

After this stage, it is not possible to culture embryos further in the laboratory. They must be transferred to the mother’s uterus. After embryo transfer, around days 6–7, the embryo escapes from its protective layer, the zona pellucida, and begins to attach to the uterine tissue.

Blastocyst-stage embryos have a multicellular structure (100–120 cells) consisting of the inner cell mass that forms the fetus (baby) and the trophectoderm cells that form the placenta. Embryos that have reached this stage are graded according to the quality of the inner cell mass and the trophectoderm structure. By transferring embryos in which both components are of good quality, it is possible to achieve much higher pregnancy rates. In addition, embryos that have reached the blastocyst stage can be successfully frozen using vitrification, an ultra-rapid freezing method, and can be successfully thawed when needed.

BLASTOCYST (DAY-5 EMBRYO) TRANSFER

Embryos that are monitored and developed in the laboratory for 5 days are called blastocysts. Embryo transfer performed on day 5 is called blastocyst transfer.

Since the first successful IVF (In Vitro Fertilization) procedure in 1978, we have witnessed breathtaking scientific advances.

One of the advanced IVF techniques used today, day-5 blastocyst transfer, offers couples who wish to have a child a much higher chance of pregnancy.

In all countries, legal limitations have been introduced on the number of embryos transferred in order to avoid the risks associated with multiple pregnancy. In our country, this limit is a maximum of 2 embryos. With day-5 embryo transfer, by transferring 1 or 2 blastocysts, the risk of multiple pregnancy is reduced while the chance of pregnancy is increased. The likelihood that embryos with chromosomal abnormalities will reach the blastocyst stage is much lower than that of normal embryos. Thus, on day 5, the chance of selecting chromosomally healthier embryos is higher. Therefore, with day-5 transfer, higher implantation (attachment to the uterus) and pregnancy rates can be achieved.

However, in order to be able to perform day-5 blastocyst transfer and obtain successful results, the IVF unit must meet the following high standards:

– Laboratory conditions must be of the highest level. Design, ventilation, cleanliness and their periodic checks must be carried out flawlessly.

– It must have sufficient and high-quality equipment. Control and calibration of all equipment must be performed regularly.

– There must be a professional and experienced team in their respective fields.

-There must be a sufficient number of experienced embryologists for techniques that require meticulous monitoring, such as blastocyst transfer.

– An IVF unit must regularly follow continuously evolving technological developments. It must be able to apply advanced IVF techniques that have a direct impact on high-quality embryo development.

WHO IS SUITABLE FOR BLASTOCYST TRANSFER?

It can be applied in all couples in whom the number of fertilized eggs is high (generally 7 or more) and day-2 embryo quality is good. On the day after fertilization, based on consultation between the doctor and embryologists who know the patient’s history, day-5 blastocyst transfer is recommended to suitable couples.

In our laboratory, blastocyst transfer is performed very successfully and very high pregnancy rates are achieved. In addition, remaining good-quality embryos after transfer are successfully frozen using vitrification, an advanced cellular freezing technique, thus offering couples a second chance.