How Many Eggs Are Frozen During the Treatment?
During each menstrual cycle, the body generally selects a cohort of eggs for ovulation, of which only one usually reaches the maturation and ovulation stage. However, egg vitrification is not performed individually but in groups of oocytes. Thus, hormonal stimulation is carried out with the goal of retrieving a high number of oocytes in each cycle.
How Many Eggs Should Be Frozen to Increase the Chances of Success?
Recommendations vary depending on the woman’s age and her ovarian reserve. In general:
- For women aged under 35, it is recommended to freeze at least 10–15 eggs.
- For women aged 35–38, it is recommended to freeze between 15 and 20 eggs due to a possible decline in egg quality due to age.
- For women aged over 38, it is recommended to freeze more than 20 eggs to compensate for the decrease in fertilization rate and embryonic potential.
What Factors Influence the Number of Obtained Eggs?
The number of eggs that can be frozen in each cycle depends on individual factors such as:
- Age: Aging negatively affects both the quantity and quality of eggs. Therefore, it is recommended to freeze eggs before the age of 35 to maximize the chances of success.
- Ovarian reserve referring to the total number of oocytes a woman has. A good ovarian reserve indicates a better prognosis for the number of eggs retrieved per cycle.
- Response to ovarian stimulation: This varies depending on the medication protocol, the woman’s ovarian reserve, and the presence of certain conditions such as polycystic ovary syndrome or endometriosis.
How Is Egg Vitrification Performed?
The vitrification process involves several stages:
- Ovarian Stimulation: Hormonal medication is administered to stimulate the growth of multiple follicles.
- Ovarian Puncture: Performed to extract the eggs once they have reached the ideal size. It is an outpatient procedure carried out under sedation.
- Vitrification: A technique of ultra-rapid freezing that allows eggs to be preserved without damage.
The survival rates of eggs after thawing range between 85% and 90%. However, it is important to note that the eggs must subsequently undergo in vitro fertilization, reach the appropriate embryonic stage, and successfully implant in the uterus. So, having enough high-quality eggs increases the chances of achieving pregnancy.