Embryo freezing is a preservation process to obtain one or more embryos and preserve them for future use in an in vitro fertilization treatment. These embryos are the result of an egg and a sperm laboratory fertilization, which were previously treated and are ready to be implanted in a woman’s uterus.
Embryo freezing is a complex process, which requires professionals with a lot of experience as it requires a very careful manipulation since the embryos are immersed in a solution known as cryoprotectants, which avoids possible damage from freezing; subsequently, they are carefully placed in a support system in hermetically sealed straws, which is immersed in liquid nitrogen at -196°C where they will freeze in a matter of seconds. Once frozen, they are stored inside a liquid nitrogen tank for preservation where they can last indefinitely (the report with more years of freezing that gave a healthy baby at home is 30 years).
This procedure can be performed as an alternative to preserve fertility, for example in women with conditions such as cancer, in which treatments such as radiotherapy, chemotherapy and some surgeries carry the risk of infertility. Also, couples who want to delay parenthood for a few years later can go through the embryo cryopreservation process to ensure success when deciding to start a family.
In addition to the above, during in vitro fertilization (IVF) treatment, ovarian stimulation, sperm freezing and egg fertilization are carried out to obtain several embryos, which develop in culture about six days, reaching the state of embryonic development known as blastocyst; from this day they can be frozen for future use.
It is important to clarify that only the embryos that are viable and of better quality are the vitrified ones since some do not survive long enough, or do not have the characteristics to go through the procedure and offer the possibility of a pregnancy.
When embryos are to be reused, they are devitrified by removing them from liquid nitrogen and placing them in an environment at 37 ° C (98.6 ° F) (room temperature); subsequently they are given a cell rehydration treatment, replacing the cryoprotectants with water. Before making the embryos transfer to the female uterus, their viability is confirmed.
The pregnancy rate is 54.2% with frozen embryos and 44% with live births. This means that frozen embryo transfer provides a very high chance of getting pregnant. With a 95% cumulative pregnancy rate at the third pregnancy attempt.
However, the success rates are not yet clear as they change from year to year; The most recent studies reveal that the success rate in IVF with cryopreserved embryos is higher because ovarian stimulation (which is part of the process to obtain mature eggs) can affect the ability of the uterus to accept the embryo, and resorting to IVF a few years later, with the embryos frozen, allows a more “natural” environment for implantation.
It was previously thought that embryo freezing carried risks, but the meticulous studies carried out on embryos make it possible to rule out those with a defect, or the probability of not surviving vitrification, thus increasing the chances of transferring healthy and strong embryos to the female body.
In addition, according to studies, the use of frozen embryos for IVF treatments entails fewer complications during pregnancy and delivery, both for the mother and the baby. This is due to the preparation of the female body and the selection of the best embryos.
As cons, we found that embryo freezing is a relatively little known method, and that IVF is usually performed with fresh embryos, even though cryopreserved eggs are used in the process. This situation reflects the complexity of the embryo freezing process, as well as the debate about the number of embryos that are obtained and what to do with those that the couple will not use.
The process of freezing embryos costs several thousand dollars in the United States, added to the cost of consultations, medications for ovarian stimulation, tests and the annual price to keep them frozen. For this reason, more and more couples choose to travel to Tijuana, Mexico where fertility treatments are given by professionals at a cost twice less.
Like eggs and sperm, cryopreserved embryos can remain stored indefinitely as they do not expire or lose their quality during the process.
Depending on the patient´s characteristics, scientific evidence has found that three embryos are sufficient to have a healthy living child at home, since a cumulative 95% pregnancy rate is reached at the third pregnancy attempt.
The embryos that remain after IVF, and that the couple no longer require, can be donated to the clinic to put them up for adoption for other couples who are not candidates for processes such as cryopreservation of eggs or sperm and who long to have a child through the most natural methods possible.
If this is not desired, assisted reproduction clinics provide the option of discarding them by leaving them out of the incubator.
Regulations on this issue vary from country to country. In general, it is sought to cryopreserve only the necessary embryos and donate to the rest, however those that are abandoned should be discarded by leaving them at room temperature, immersing them in alcohol or hypotonic saline solution to create an osmotic shock, and subsequently sent them to an incineration furnace.
The Fertility Center is an Assisted Reproduction clinic in Tijuana, where you will find the specialists you need to make your dreams of starting a family come true; We have cutting edge facilities and technology, highly specialized doctors who continue to train in the most current treatments, as well as a long history of success stories with our patients. Schedule your assessment appointment through the means available on our website, we will gladly assist you.
1.- Schedule your appointment
2.- Talk to our specialist
3.- Prepare your studies
4.- Attend your consultation
5.- Start your treatment plan
Questions or clarifications calls the 858 867 4090