27 Sep Fertility preservation, when and how?

There are times when a woman’s ability to become pregnant weakens and is threatened. Not only age is a challenging factor, but also some diseases or treatments can cause infertility. In this blog we will talk about fertility preservation and answer some of the questions our patients had before coming to our fertility clinic.

The ideal biological age to conceive is between 20 and 30 years old but nowadays, due to social changes, women are delaying childbearing considerably. From the age of 35 onwards, the quality and quantity of eggs decreases considerably. A biological process that, a few years ago, could not be controlled, as egg freezing techniques did not allow good results. Today, thanks to the technique of vitrification, eggs can be cryopreserved without affecting their quality.

Now women can take control of their maternity, stopping the biological clock by vitrification of their eggs. In the case of women, freezing their eggs allows them to have the same chances of pregnancy as they had at the time of preservation. Therefore, the quality of the egg does not decrease and allows you to use them at the best economic and emotional moment with the confidence and security that the process itself confers.

Fertility preservation is based on the collection of eggs and their subsequent conservation, to be used at the moment when the woman or the couple wants and decides to use them, i.e. the right moment.

In other cases, this technique is not performed for biological reasons, but for ethical reasons where it is not desired to freeze embryos, or for medical reasons, such as if the woman has to undergo radio or chemotherapy treatment that may affect her fertility.

Vitrification technique

Egg vitrification consists of protecting the eggs by means of cryoprotectants, which prevent the formation of ice crystals inside the cell and, therefore, prevent them from causing cell damage. They will be submerged at -196C with a very rapid temperature drop.

97% of frozen oocytes retain their qualities intact, in women under 35 years of age. A much higher success rate than conventional freezing techniques.

Egg vitrification allows a woman to obtain the same success rates in reproductive treatment as she could have at the time of freezing the eggs, regardless of the age at which she uses them, i.e. it allows her to stop the biological clock.

Eggs that have been retrieved from the age of 18-24 allow a pregnancy rate of approximately 90%.

How is preservation carried out?

• On the first consultation, a complete study will be carried out and the patient will be informed of all the steps to be taken during the preservation treatment. At the next visit, the results of the analytical tests will be given and observed and the treatment to be followed will be prescribed.

• Ovarian stimulation. This step takes place during the menstrual cycle and lasts between ten and twelve days. Through hormonal injections, the ovary is stimulated and multiple eggs grow inside each egg. During this process, the gynaecologist will monitor how the ovary evolves and will control the number and size of the follicles (cavities in which an egg develops) that develop. When an adequate number and size of follicles is obtained (16-18 cm), a dose of the hormone hCG is administered, which favours the final maturation of the eggs.

• Follicular puncture. This is a surgical procedure, which does not require anaesthesia but only sedation, and is performed to obtain the eggs from inside the follicles of the ovary. The aspiration is guided by ultrasound and introduced by an ultrasound machine with a needle that punctures the ovarian follicles and aspirates the liquid. This is then transferred to test tubes, which are kept at 37°C and taken to the laboratory, where the liquid is analysed and the eggs are obtained.

• Vitrification of oocytes. The oocytes are subjected to increasing solutions of cryoprotectants to protect them and are then immersed in liquid nitrogen at a temperature of -196 °C.

Male fertility preservation

To preserve a man’s fertility, a semen sample is frozen to keep the gametes unaltered and in perfect condition. Therefore, with the passage of time, the man will be able to maintain the quality of the semen for a future pregnancy, which will take place at an age when the man is not at his most fertile.

However, on most occasions, this technique is used for men who have to undergo aggressive treatment, such as chemotherapy, and whose fertility may be affected, as their sperm quality may be greatly reduced after the treatment.

But how is freezing carried out? Well, after a sample of the man’s semen has been obtained after a period of sexual abstinence of 1 to 3 days, the quality of the semen is analysed and if it is optimal, the semen is mixed with a cryoprotectant and the straws are introduced and stored at -196 °C until the moment they are to be used.

Would you like more information about our preservation and vitrification service? Contact us or come to our office for a free initial consultation, where we will inform you about the process and give you an estimate for the treatment.