What Is Oocyte Cryopreservation?
Oocyte cryopreservation, also known as egg freezing, is a process wherein a woman’s eggs are extracted, frozen and stored for later use. The treatment cycle is similar to that of an IVF procedure, beginning with ovarian stimulation, wherein medications that contain Follicle Stimulating Hormones are administered in the form of an injection for about 10 to 12 days.
Once the eggs are ready, they are retrieved through a procedure known as oocyte harvesting or the ‘egg retrieval’ process. During this process the eggs are removed with a needle placed through the vagina with the help of an ultrasound machine. An intravenous sedation is given to the patient, which makes the procedure quite painless.
The retrieved eggs are then, evaluated in the clinical laboratory and frozen in cryo-protectants. The cryo-protectant is a mixture of solvents that safeguard the delicate eggs from intracellular ice formation during the freezing process.
(Formation of ice crystals inside the cell structure of the egg can cause damage to the membranes and rupture the cell.) When a patient is ready to use the eggs, they are thawed and fertilized with a single sperm in an Intra Cytoplasmic Sperm Injection (ICSI) cycle and transferred back to the uterus as an embryo to achieve pregnancy.
What’s the purpose of egg freezing?
Egg freezing is a way of preserving your fertility. It might not be the right time for you to try for a baby now, but freezing your eggs could enable you to conceive later.
There are lots of reasons why you may decide to take this step:
- You’re about to have treatment for cancer. Cancer treatments like radiation therapy or chemotherapy can impact your fertility.
- You have a medical condition that may make it more difficult for you to conceive, such as endometriosis, sickle cell anemia, diminished ovarian reserve (where the eggs in your ovaries decline in number or quality), or an autoimmune disease such as lupus.
- Your family history. If your mother went through menopause early, meaning there’s an increased risk that you will too, you might choose to preserve some eggs when you’re younger.
- Starting a family isn’t possible right now for a variety of reasons, but you’re worried about your fertility declining with age. You hope that the stored eggs may increase your chances of having a healthy baby in the future. This is also known as “social” egg freezing (i.e. there’s no direct medical reason for it).
- It’s an alternative to freezing embryos. You might have ethical or religious concerns about freezing embryos (fertilized eggs) for IVF.
