Vitrification of oocytes
Leading technique to preserve the possibility of motherhood
This technique consists of ultra-rapid freezing of the eggs for their conservation and later use. With this ultra-rapid freezing, these cells are kept unaltered, avoiding the formation of ice crystals for an indefinite period.
This treatment is indicated for:
– Women who want to delay their motherhood. From the age of 35, fertility rates in women are falling and at the age of 40 they drop considerably, which means that in many cases it is not possible to conceive with own eggs.
– Cancer patients. In many cases, radiotherapy or chemotherapy treatments produce a definitive sterility in women of childbearing age.
– Primary ovarian insufficiency caused by pathologies such as endometriosis, autoimmune diseases, collagen diseases or a family history of early menopause.
Before beginning this treatment, an individualized evaluation of the woman is carried out to find out about her ovarian reserve and her general state of health. In egg vitrification, the chances of success depend mainly on the patient’s age and the condition of her ovaries.
Once this evaluation has been carried out, ovarian stimulation and puncture is performed, and then the obtained oocytes are vitrified.
The eggs are stored in liquid nitrogen for future devitrification and use.
The optimal age for a woman to vitrify her eggs is around 35. At this age, the woman’s egg count is 25,000, which is very low compared to the approximately 250,000 eggs she had at her first ovulation. From this point the loss of oocytes accelerates rapidly until the time of menopause, when a woman has only about a thousand.
The egg vitrification technique has become, consequently, the great alternative to delay female fertility.
How the the thecnique;the vitrification is performed?
The new egg vitrification technique, so called to differentiate it from the usual slow freezing procedure, consists of ultra-rapid freezing of the eggs so that no intracellular crystals are formed.
It provides a survival rate of the oocytes to the thawing process of 82-96% with a subsequent fertilization rate of 75-90 % and an implantation rate of 32-55%.
The process requires ovarian stimulation with hormones and the aspiration of the oocytes by the vaginal route under sedation.
After vitrification, the eggs can be stored for as long as desired.
Once the patient decides to use them to become pregnant, they are thawed and fertilized with the spermatozoa that the patient wants, either from a partner or from the sperm bank.
It is important to emphasize that the egg vitrification by itself is not a guarantee of safe motherhood. It must be explained to patients that not all the oocytes obtained after ovarian stimulation and follicular puncture have the same morphological and functional quality. So not all of them fertilize.