What is egg freezing?
Egg freezing or oocyte vitrification is the process that is used for the preservation of a woman’s fertility. This flash freezing technique allows you to preserve your current probability of pregnancy for the future in the event that you don’t achieve a spontaneous pregnancy.
What are my chances of getting pregnant?
It is often thought that it is very easy to get pregnant, that it’s just a matter of having sexual intercourse, and that’s it! However, we don’t really know what our chances of pregnancy are, or when the best time to get pregnant is (during the fertile window of the menstrual cycle). The monthly likelihood of getting pregnant for women, in the case of having unprotected sex is as follows:
|Monthly pregnancy rate|
|34 or under||15-17%|
We can see that it is not so easy to get pregnant and that the monthly chances of success are not particularly high. In addition, the age factor has a major impact on success rates, so that the sooner a woman’s fertility is preserved, the better the chances of becoming pregnant.
The egg freezing process: step by step
Vitrification is the technique we use to preserve a woman’s mature eggs. The method we use consists of a flash freezing process in which we immerse the eggs in liquid nitrogen at -196ºC, so that we avoid the formation of crystals as the speed of freezing is so fast, and thus allow the eggs to have a higher survival rate for the day we need them. With this method, these cells remain unchanged until we want to use them.
After a process of ovarian stimulation, the oocytes are retrieved from the ovary by puncture. It is a rapid intervention that is performed under anaesthetic sedation.
Then, in the laboratory, mature oocytes are selected and those that have not reached a sufficient degree of maturity, or even the degenerated ones, are discarded, because they are unsuitable for fertilisation.
They are bathed one by one in a in a sucrose solution, which removes the water they contain in order to prevent crystals forming during freezing, which could damage them.
Finally, the oocytes are inserted in a small tube called a straw, ready for cryonization. A straw is a tube in which the cells or embryos are arranged, they can be frozen as a group or individually.
The straws are immersed in liquid nitrogen at a temperature of -196°C, and in a matter of seconds they are frozen without ice forming.
Once frozen, the eggs will remain unchanged in the nitrogen tank for an indefinite time and can be clearly identified according to the patient’s name and identification code, until they are used.
At the end of the egg freezing process, the patient receives, as a tangible keepsake, a card with the image of the oocytes that have been vitrified.
Treatment success rates
Depending on your age at the time of freezing the oocytes, the success rate of the egg freezing treatment varies. From the age of 35, the reproductive potential of a woman’s eggs decreases exponentially, so age is a determining factor. The number of eggs goes down over time and reduces the chances of pregnancy every year, until having children naturally becomes difficult and it may be necessary to receive an egg donation from another woman. For this reason, the younger your fertility is preserved, the better the success rate; because the frozen eggs of a 35-year-old woman will always be better than those of a woman aged 38. These are the success rates for embryo transfers proceeding from devitrified eggs:
|Success rate by age|
|34 or under||61%|
Once the eggs are frozen, what happens?
After the puncture, the eggs will be frozen in different nitrogen tanks, for safety reasons, until the day you need them or decide what to do with them. As a precaution and depending on the number of oocytes that are extracted, they will be inserted in different straws to avoid thawing them all at once on the day you want to use them.
The passage of time does not alter the quality of the preserved eggs and their characteristics will remain intact thanks to vitrification. Also, only you can decide what to do with them. For this reason, it is very important that you inform us of any change in your contact information (phone numbers, postal address, email, etc.).
At Timefreeze we take care of all the details and we want you to feel as comfortable and safe as possible in the hands of our experts.