What to know about embryo transfers

1. 🩺 Features of the embryo transfer procedure
2. 🤰 Types of manipulation
3. ⭐ What happens before, during, and after embryo transfer?

Considering different information, the long-awaited miracle happens in 40-50% of such cases. However, thanks to medical innovations, the number of pregnancies after IVF is steadily increasing. For example, transfer of cryo-frozen embryos increases the frequency of pregnancies up to 50-70%! And Feskov Human Reproductive Group offers a unique service - transportation of cryo-embryos from any country to use them in reproductive programs.

Features of the embryo transfer procedure

The transfer of the ready embryo into the uterine cavity of the fair sex is the final, extremely important part in the process of conception in vitro. The most gentle and accurate transfer to the most suitable place of the uterus allows the embryo to attach to the mucous membrane and begin its development into a baby.

During IVF, the patient takes specially selected hormonal drugs that stimulate the functioning of the ovaries, so that not 1-2, but about 10-15 good eggs mature in them.

Matured oocytes are removed from the ovaries through transvaginal puncture and transferred to the embryological laboratory where the very mystery of the birth of a new life takes place - the eggs are fertilized by sperm by the hands of embryologists.

If conception has occurred, embryos are cultured for 2-5 days, and then transferred to the uterus of the expectant mother. When the embryo is implanted into the wall of the uterus, pregnancy occurs.

A similar method of conception is required in different cases when the natural process is impossible in principle or is very difficult. There are many reasons for IVF, among them the following ones:

• ovulation disorder - when it is irregular, fewer eggs are produced that are available for fertilization;
• pathology of the fallopian tubes - the passage through which the oocytes reach the uterine cavity. In the event of scarring or other damage, the path of the eggs will be difficult and not always successful;
• endometriosis - when the uterine tissue grows excessively, which indicates a malfunction in the reproductive system;
• ovarian wasting syndrome - when the ovaries do not work normally, do not produce the right amount of estrogen and do not produce eggs;
• fibroids - small benign tumor-like formations on the walls of the uterus that can prevent the oocyte from becoming its inhabitant;
• genetic pathologies - some inherited factors may prevent pregnancy from occurring;
• male problems - low sperm production, inactive sperm, testicular deformities and other reproductive abnormalities in a partner.

These and other reasons can become an obstacle to natural conception.

Types of manipulation

As soon as the egg is fertilized and becomes an embryo, experts choose one of the best ways to transfer it to a woman:

1. A procedure with fresh embryos, which, immediately after fertilization and cultivation for 1-2 or 3-5 days, move to the uterine cavity for implantation. For this, only the best and healthiest specimens are selected, tested by the method of pre-implantation genetic screening PGD / NGS. In addition, the study allows you to determine the sex of the child.
2. Cryopreserved gamete manipulation. All healthy embryos that have remained from previous IVF cycles can be frozen at ultra-low temperatures and stored in liquid nitrogen in Dewars until future use. They are easily defrosted without loss of viability in 99% of cases and are transferred to the uterus. Thus, financial and time resources can be saved by skipping the stage of ovarian stimulation, oocyte extraction, and in vitro fertilization.
3. Action with an embryo that has developed to a blastocyst. When many embryos are formed as a result of fertilization, they usually wait for their development to the blastocyst stage. And this is 5-6 days of cultivation. According to some studies, the success rate of embryo transfer at this stage is higher than the transfer procedure on day 3. However, other studies argue that this can be risky and not in all cases the method should be applied. It all depends on the medical indication.
4. Auxiliary hatching. This is a microsurgical manipulation that helps the growing blastocyst to leave its shell - that is, to hatch outward. To do this, by mechanical, chemical means or a laser, specialists thin out the lustrous surface of the embryo so that at the right time it can hatch and implant into the wall of the uterus. Research has shown that the method is not as effective in fresh embryos as in frozen embryos. Successful pregnancies with cryo-embryo hatching are increasing.

But how much is it advisable to transfer embryos? Some doctors believe that one is enough, others that two - as this doubles the chances of successful gestation. In fact, it depends on the age and individual parameters of the woman. A patient under 35 years of age with a high chance of a normal procedure will receive only one embryo.

This is confirmed by the study, which says that in women under 38 years old, replanting one embryo reduces the risk of multiple pregnancies. And there is no need for several embryos, since this does not affect the level of live birth.

If the chances of a successful result are low, doctors may recommend the “increased load” method when 3 or more embryos are transferred. So that at least one of them will take root.

The degree of embryo survival is determined by the cause of infertility, genetic disorders, and the individual characteristics of the female body. However, some data suggest that frozen embryos take root better than fresh ones. In addition, frozen gametes can be used for additional transfers and repeated IVF cycles, which is very convenient for everyone.

What happens before, during, and after embryo transfer?

Two to three days before the transfer procedure, the doctor collects eggs and sperm. Further, the best representatives of the genetic material are selected by special methods. Then the fertilization process takes place in vitro.

Fertilized eggs will be cultured for 3-5 days. With the development of a decent number of good embryos, 1-2 can be selected for transfer, and the rest can be frozen for the next IVF cycles.

The manipulation is monitored by an abdominal ultrasound with a full bladder for better visualization. The embryos are placed in a catheter that passes through the cervical canal into the uterus. At the most suitable place - in the middle of the cavity, the embryos are released outside.

However, pain relief is usually not required. However, there may be slight discomfort, cramping, flatulence, or vaginal discharge.

After manipulation, you can lie on your back for 1-2 hours. Before the next visit after 2 weeks, when pregnancy can be diagnosed, it is better to refrain from physical activity, sexual activity.

Possible risks of action

The gamete transfer procedure does not carry any special risks. Unpleasant consequences, most likely, can be associated with the previous procedure of hormone therapy.

The most serious risk of transfer is the likelihood of several fetuses or multiple pregnancies at once. This happens when several separate gametes are attached to the walls of the uterus at the same time. This can lead to the birth of dead babies or children with insufficient body weight, other developmental pathologies. Since, usually, multiple pregnancy leads to premature birth and health complications in a pregnant woman. This happens often with IVF, and, very rarely, with the natural process of conception.

What complications sometimes occur:

• slight bleeding;
• transformation of vaginal discharge;
• infection;
• the consequences of anesthesia, if used.

The likelihood of spontaneous abortion (miscarriage) is about the same as that of a naturally occurring process.

Feskov Human Reproductive Group offers patients from all over the world the most modern reproductive technologies, including IVF, genetic screening of embryos, surrogacy, and donation services. Various programs for a fixed price without additional payments allow even in the most hopeless cases to become happy parents. We use even the slightest chance of success and guarantee the birth of a healthy baby!

Authors, contributors:

Olena Somova
Embryologist

published: 22 October 2021
updated   : 03 March 2023

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