Preservation of female fertility involves the retrieval and freezing of eggs, or oocytes, and sometimes embryos, for future use, usually several months or even years later.

To obtain oocytes suitable for freezing, a woman undergoes the same treatment procedure as a woman seeking infertility treatment, after examination and consultation with a doctor. The process is completed by retrieving follicular fluid containing oocytes from the ovaries under short-term anesthesia. In the IVF laboratory, the oocytes are then identified and transferred into culture media. After standard procedures, the oocytes are vitrified, meaning they are rapidly frozen in a special medium to the temperature of liquid nitrogen (-196°C). All quality oocytes are frozen, usually two to three per separate straw (comparable to a special straw). Freezing oocytes (or embryos) halts their biochemical processes, and at -196°C they remain unchanged throughout their storage in a cryogenic container with liquid nitrogen.

For women undergoing treatment for an oncological disease (chemotherapy, radiotherapy), which is expected to potentially negatively affect future fertility, the entire process is initiated as quickly as possible. A gynecologist specializing in assisted reproduction, in collaboration with an oncologist, optimizes the treatment for the specific woman. If the woman’s health allows, repeated ovarian stimulation and oocyte retrieval are possible to maximize the chances of future pregnancy and childbirth.

If the woman has a partner with whom she plans to have a child, it is optimal to fertilize the oocytes with the partner’s sperm, culture the resulting embryos, and after several days, usually five, freeze the embryos with potential for further development. If the woman does not have a partner, the oocytes are frozen. Alternatively, with agreement, both approaches can be combined.

In rare cases, e.g., when planned removal of the ovaries is indicated, retrieval and freezing of ovarian tissue may be considered. This is a very exceptional and special situation that goes beyond the general information; if this approach is required, the physician will consult directly with the patient.

For patients with an oncological diagnosis, the health insurance covers IVF treatment, freezing, and storage of reproductive cells.

For women who are healthy but plan to have children later for any reason (socioeconomic reasons, lack of a partner, etc.), it is possible to freeze and store eggs – oocytes – in a cryogenic container with liquid nitrogen at a temperature of -196°C for later use. This method of fertility preservation is referred to as social freezing. Health insurance does not cover this treatment.

• Quality of oocytes varies for each woman; the number retrieved can differ even with similar ovarian stimulation.
• Oocyte quality declines with age; optimal ovarian stimulation and egg retrieval is before 30 years old, or up to 35. After that, both quantity and quality usually decrease.
• Not every retrieved egg will develop into a viable embryo. For example, around age 30, roughly one-third to half of retrieved oocytes are of good quality.
• Oocyte assessment is based only on morphological parameters visible under a microscope; chromosome count (e.g., aneuploidy, the most common reason for embryo development arrest) cannot be seen.
• Retrieving oocytes does not guarantee that all good-quality eggs will develop into viable embryos.
• To obtain a sufficient number of frozen eggs for future use, ovarian stimulation and egg retrieval can be repeated (e.g., twice).
• After thawing and fertilization, sperm quality is important for successful fertilization.
• The woman’s health at the time of embryo transfer must be considered.
• Generally, the probability of embryo implantation in a healthy woman’s uterus does not change with age; what matters is the age at which the oocytes were retrieved.
• The likelihood of pregnancy using thawed oocytes is individual, just like with standard assisted reproduction. Some women conceive on the first cycle, others on the second, third, or fourth attempt. Rarely, assisted reproduction may not lead to pregnancy.
• If you are 30 and plan pregnancy in 1–2 years, assess your fertility first; if it’s normal, social freezing may not be necessary.
• If you are 30 and plan pregnancy in 10–15 years, social freezing can be a suitable option.

IT IS GOOD TO BE A REALISTIC OPTIMIST ☺

If you are considering freezing oocytes or embryos, schedule a consultation at the Assisted Reproduction Center, where the doctor will discuss the process in detail and recommend the optimal procedure after examinations and blood tests.

If you have frozen oocytes or embryos and wish to conceive using assisted reproduction, you will schedule an appointment at the clinic (both woman and man), where the doctor will perform the necessary examinations and determine the timing for the embryo transfer into the woman’s uterus. In the laboratory, a suitable number of oocytes will be thawed several days in advance, as agreed with the doctor or embryologist. They will be fertilized with the partner’s sperm, cultured for 2-6 days, and the embryo with the highest potential for further development will be prepared for transfer into the uterus on the designated day. If there are multiple suitable embryos, the remaining ones will be frozen. If a frozen embryo already exists, it will be thawed on the day of the planned transfer, and embryo culture in the nutrient medium occurs only on that day. The embryo transfer into the uterus is painless, performed using a special catheter under ultrasound guidance. Whether the embryo has implanted into the uterine lining will be known within 2-3 weeks.