Egg freezing or oocyte cryopreservation is a method of fertility preservation where a woman’s eggs are harvested, frozen and stored. In this procedure eggs are extracted from the ovaries, which are stored and then preserved for future use.
Women with certain medical conditions required to undergo chemotherapy, radiotherapy or surgery which could affect the functioning of the ovaries take egg freezing into consideration. Couples who plan to delay parenthood by choice also opt for this medical procedure.
Once the eggs are extracted, their maturity is assessed under a microscope, and those eggs that are mature are cryopreserved. Storing the eggs for longer duration does not appear to have negative effects. When one chooses to use their frozen eggs, they are thawed, fertilized with sperm in a lab, and implanted in the patient or a gestational carrier’s uterus.
Frequently Asked Questions on Egg Freezing
Q. Who should consider egg freezing?
A. Egg freezing is beneficial for women wishing to preserve their fertility for the future including:
Women who want to delay starting a family in order to pursue educational, career or other personal goals
Women diagnosed with cancer or tumour and need chemotherapy
Women who prefer egg freezing over embryo freezing
Q. When should a woman ideally freeze her eggs?
A. The answer to egg freezing or oocyte cryopreservation is that a woman should opt for it during her prime reproductive years —20s and early 30s — to take advantage of quality and quantity. A woman is born with all of the eggs she will ever have, and over time they diminish in number and quality. This decline explains why a woman in her 40s has only a 5 percent chance for becoming pregnant each month.
Basic fertility testing, including antral follicle counts, hormone and AMH blood testing, assesses your ovarian reserve. A clearer picture of your egg quantity and ovarian function may lead you to opt in (or out) of elective fertility preservation.
Q How is it done?
A. In order to retrieve eggs for freezing, a patient undergoes the same hormone-injection process as in-vitro fertilization. The only difference is that following egg retrieval, they are frozen for a period of time before they are thawed, fertilized and transferred to the uterus as embryos. It takes approximately 4-6 weeks to complete the egg freezing cycle and is consistent with the initial stages of the IVF process.
Q. How many eggs should be preserved for future pregnancy?
A. If 10 eggs are frozen, 7 are expected to survive the thaw, and 5 to 6 are expected to fertilize and become embryos. Usually 3-4 embryos are transferred in women up to 38 years of age. We therefore recommend that 10 eggs be stored for each pregnancy attempt. Most women 38 years of age and under can expect to harvest 10- 20 eggs per cycle.