WHO CAN UNDERGO EGG FREEZING?
The Egg is the female reproductive cell, and it is the largest cell in the body. Egg freezing means when a woman’s eggs, which are obtained after ovarian stimulation, are stored for future use by in vitro fertilization method.
WHO CAN UNDERGO EGG FREEZING?
Egg freezing is allowed under certain conditions to preserve fertility with the regulation on Assisted Reproductive Therapy and Assisted Reproductive Treatment Centers published on September 30, 2014.
In situations where;
- There is a family history of early menopause, such as mother, aunt, and sister of the woman,
- Presence of a disease that required the removal of ovaries,
- In case of need for chemotherapy or radiotherapy for any reason,
- If the ovarian reserve is determined to be low and there is no plan to have a baby at the moment,
A woman’s eggs can be frozen and stored.
HOW THE EGG FREEZING PROCESS IS PERFORMED?
In order for egg freezing to be performed, first of all, the development of multiple eggs in the ovaries of the woman must be ensured. Because under normal conditions, every woman ovulates only one egg every month and loses a number of egg cells that vary from person to person before they can develop. With the help of drugs to be given from outside, it is essential to enlarge the eggs that will be lost and to ensure the development of multiple eggs. For this reason, first of all, after the examination of the woman, the appropriate stimulation protocol for ovarian stimulation is selected. The choice of this protocol is made according to the age of the woman, her menstrual pattern, ovarian reserve and whether there is an additional health problem.
Then, in the desired month, appropriate drugs are started within the scope of this selected protocol, and egg-enhancing drugs are started with the woman’s menstruation. Until the egg sacs, namely the follicles, reach the desired size, in general, we want the leading ones to reach 17 mm in size, followed by ultrasonography at intervals of a few days. Generally, 8-10 days of ovarian stimulation is required for the follicles to reach the desired size. You can read our Stimulation of the Ovaries article to get details about stimulating the ovaries.
When the follicles reach the desired size, a final shut injection is applied to ensure the maturation of the oocytes, and then oocyte pickup is performed under light anesthesia. Since we almost always perform the oocyte pickup procedure under anesthesia in our center, no pain is felt throughout the procedure and the process takes approximately 10-15 minutes.
On the day of oocyte pickup, the oocytes are evaluated for their maturity under the microscope after the cells around them are removed, and the mature eggs are frozen in groups of two or three with the vitrification technique. In the vitrification technique, the liquid inside the cell is released out of the cell with the special solutions, and replaced with the liquid called cryoprotectant. Then the oocytes are stored in tanks containing liquid nitrogen at -196 °C. After collection, only mature oocytes can be frozen and stored. Approximately 80% of the oocytes collected are mature.
WHAT ARE THE IMPORTANT POINTS IN EGG FREEZING?
Stimulation of the ovaries in a proper way will increase the number of eggs to be obtained at the end of a single stimulation cycle. For this reason, choosing the most appropriate ovarian stimulation protocol according to the individual characteristics of the woman and reserve of the ovaries and using the appropriate drug doses will affect the number of eggs to be obtained. In addition, the timing of the final shut injection also affects the chances of success. Early or late trigger may reduce the number of mature eggs or cause problems such as early triggering.
HOW MANY EGGS SHOULD BE FROZEN TO PROTECT FERTILITY?
Age of the woman is an important factor that influences both egg count and egg quality. Every girl is born with a fixed number of egg cells from birth, and from puberty, one egg is laid every month and she lose a certain number of eggs too. However, no woman has a chance to produce new eggs either spontaneously or with medication. Therefore, as age progresses, the number of eggs remaining in the ovaries decreases. In addition, as the age of the woman progresses, the risk of getting chromosomally problematic and unhealthy eggs increases, and therefore, getting pregnant becomes more difficult compared to younger ages, the risk of miscarriage and loss of the pregnancy increases, and the risk of anomaly, especially Down Syndrome, increases in the baby.
Because of those, the number of eggs to be frozen varies according to the age of the woman. While freezing 8-10 mature eggs under the age of 35 may be sufficient, more mature eggs will be needed over the age of 40. Therefore, freezing only a few eggs does not mean that fertility is preserved. To better understand the impact of female age on fertility, you can read my Preimplantation Genetic Testing (PGT-A) article.