Egg freezing is a revolutionary advancement in the field of assisted reproduction technology (ART), pioneered during the mid-20th century and since then has been constantly evolving and improving over the years. At present, egg freezing constitutes an indispensable part of modern ART practice. It is a process that begins with the collection of oocytes via follicular fluid aspiration. This could be performed following controlled ovarian stimulation, either with gonadotropins for maximum oocyte yield (conventional stimulation) or with a combination of oral medication and/or reduced gonadotropins (mild stimulation/ mini IVF). Alternatively, multiple natural or modified natural cycles with a small yield each (1-2 oocytes) could be used to cumulatively collect the desired number of oocytes. Following egg retrieval, the collected oocytes are subjected to a process called vitrification, which entails near instantaneous freezing of the oocyte, facilitated by a liquid nitrogen bath. The process inhibits the formation of ice crystals, a phenomenon that occurs is liquid water freezes, which would otherwise injure the oocyte and reduce its survival chances at thawing. Oocytes are then stored in liquid nitrogen tanks, where they can remain for multiple years in a stable condition until needed in the future.
Egg freezing has multiple indications in ART, which have also evolved over the years. Initially, it was mostly reserved for young women and girls who had not had children or completed their family plan at the time and who had to receive gonadotoxic (i.e. toxic to the ovaries and oocytes) medical treatment. This is most commonly the case in cancer treatment, such as chemotherapy and radiotherapy, which severely diminish the fertility potential of the ovaries. Although ovaries rarely ever recover, the uterus is more resistant to this drug-induced toxicity. Therefore, by performing egg freezing before their cancer treatment, young women preserve their fertility prospects until the day they are ready to proceed with motherhood. Nowadays, the applications of egg freezing have expanded to include women who wish to delay childbearing for nonmedical reasons, a phenomenon also known as “social freezing”. Since fertility and euploidy rates drop steadily after 35 years, timely cryopreservation of oocytes may be a lifeline for the future, as it would increase the chances of pregnancy without the need for more expensive ART programs, such as oocyte donation.
Overall, egg freezing is a versatile and reliable option for women with medical and nonmedical reasons to delay childbearing and increases the chances of conception even during advanced reproductive age. However, one should tread carefully and not delay their family plan indefinitely; the oocytes may be frozen in time, but the uterus and the rest of the body continue ageing.
Vitrification is a very advanced technique and ART because we are, just imagine here, freezing one cell. When we are freezing the embryo, the embryo of Day 5 status which is the blastocyst has a few hundreds of cells and here we are talking about freezing one cell so, the freezing itself and the thawing, meaning the melting. When we’re using them, it is a lot of technology dependent process. We need to have a very good lab, the standard of the lab should be very good these days we use vitrification unfortunately, I am aware that even in very good cities some of the labs have still not completely shifted to vitrification, they still have been doing slow freezing which is an old a good tested way of freezing and a lot of eggs have been frozen like that and they are still being used but vitrification has been a very big thing.
Egg freezing is also known as oocyte cryopreservation. It is a procedure to store women’s eggs for use in future fertility treatment. In this way women have the possibility of being a mother in the future with more biological competent eggs that have been frozen in the younger age. Current rapid vitrification techniques preserve oocytes so it has good survival rates. The main characteristic of vitrification technique is that no water crystals are generated so in this way you will able to prolong your fertility capacity over time, being able to have a pregnancy later with your own genetic globe in an age that in which women who have not taken this precaution will have to face the indication of egg donation.
Egg freezing or oocyte vitrification has two main parts: the first one would be what we call ovarian stimulation and this is not different to what we would be doing in a normal IVF cycle. We will give you drugs to get your ovaries stimulated and for that we usually need around a couple of weeks as with all the ovarian stimulations, we try to start with your period but we can do a random start as well especially for cancer patients because we don’t have time and then we have to start any time because we can’t really face a delay waiting for the period to come. Roughly would be like a couple of weeks with hormonal stimulation and then you will undergo what we call a no side retrieval and then with that, we will get the eggs frozen. We call it vitrification because it’s actually not freezing, it’s an ultra quick freezing which preserves the quality of the eggs with its integrity and then this is what has really made a difference in terms of survival rates.
Egg freezing is the procedure that we do cryopreserve eggs to keep them in liquid nitrogen and store them for the future. This process basically involves undergoing an IVF cycle so that means controlled ovarian hyperstimulation where injections are given to you to stimulate the ovaries to create or form or grow more than one follicle so that we can eventually pick up the eggs from these follicles via a procedure and then we fix and refreeze them. The freezing process itself is highly technical and quite complex as very delicate, however modern techniques now allow us to freeze much better and increase success rates than it used to be in the past. Once we freeze those eggs they’re stored in liquid nitrogen at minus 197 degrees celsius for your use in the future.
Egg freezing is a hot topic right now. And the reason why it’s a hot topic is for many years we did not understand how to freeze eggs. The human egg is made up of about 80% water, and imagine trying to freeze something that’s full of water, you’re going to get ice crystals that form or ice formation. This ice crystal; when you thaw the egg out then in the past would damage the chromosomes and you wouldn’t be able to use those eggs to have a healthy child in the future. But in 2012, the American Society of reproductive medicine determined that egg freezing was no longer experimental because of a procedure called vitrification. With vitrification what we do is that we remove the water from the egg prior to freezing it and then we undergo what’s called Flash Freezing, in other words, a process where you freeze it rapidly. And by doing that, it’s been shown that your success rates with a frozen egg from a healthy egg that’s frozen have the same success rate as a fresh egg. So it allows women the chance to freeze their eggs at a younger age and hopefully never use those frozen eggs but they do have to use those frozen eggs in the future. They’ll have the same success rate as if they were using the fresh egg.
When we use the term egg freezing, we actually understand that we have to have mature oocytes that we are going to take through vaginal oocyte pickup. And then we freeze them in the lab during the so-called vitrification procedure.
