Egg freezing, clinically known as ‘oocyte vitrification’, is a procedure where eggs are extracted, frozen and stored for use on a later date. The technique of vitrification involves flash freezing the eggs in a glass-like state without the formation of ice crystals. This method allows the eggs to sustain their original properties at the time of retrieval.
Why freeze eggs?
The number of eggs a woman produces in her lifetime is determined at birth. Her ovarian reserves and egg quality will begin to decline around 30-35 years of age. Egg vitrification helps to preserve fertility when the woman is younger and healthier, and is suitable for women who:
- Are of childbearing age but is not yet ready to have children.
- Have low ovarian reserves due to medical conditions.
- Are due for aggressive medical treatments such as chemotherapy, radiotherapy, or surgeries for tumours.
What does the procedure involve?
Step 1: The woman first has to undergo controlled ovarian hyperstimulation with hormone injections for ten or twelve days. The hormones help promote and stimulate follicle growth in the ovaries which contains the eggs.
Step 2: During the stimulation phase, ultrasound scans will be performed every two to three days to monitor the progress of the follicle growth.
Step 3: Once the follicles reach the right size, a final injection is administered. This injection helps the eggs mature, enabling them to be retrieved after 36 hours.
Step 4: Egg retrieval or ‘Oocyte pick-up’ (OPU) is performed under sedation to avoid discomfort. Once retrieved, the number, quality and morphology of the eggs will be assessed before the vitrification process.
How are vitrified eggs used?
When the woman is ready for a baby, her eggs are first thawed. Around 90% of eggs that are thawed will survive the process.
Once the eggs are thawed, they are fertilised with the sperm of her partner or a donor using the Intracytoplasmic Sperm Injection (ICSI) technique. When embryos are formed, they will be incubated in the lab for 3-5 days before they are transferred into the woman’s uterus.
What are the advantages of egg vitrification?
Egg Vitrification allows a woman to:
- Have biological children at a later date.
- Decide when she wants to start a family without worrying about egg quality declining because her eggs will have the same quality and age of the time they were vitrified.
- Have children using her own eggs after aggresive medical treatments that might inhibit fertility such as chemotheraphy, radiotheraphy, or autoimmune diseases which requires cytotoxic medications and treatments.
Facebook, Apple and Google has recently announced that they are willing to sponsor their female employees who want to freeze their eggs. This certainly has brought about a new perspective on giving women reproductive freedom.
TMC Fertility 