Also known as Oocyte Cryopreservation
What is Egg Freezing?
AART has been offering egg freezing, also known as oocyte cryopreservation since 2017 for patients who are about to undergo treatment for cancer, and choose to freeze their eggs in advance of treatment.
AART also offers egg freezing for age-related fertility decline (often referred to as “social egg freezing”), for patients who choose to store their frozen eggs for non-medical purposes. The intention of the procedure is that the patient may choose to have the eggs thawed, fertilized, and transferred to the uterus as embryos at a later time, to facilitate a pregnancy in the future.
Ovaries age more rapidly than other organs and tissues. As a result, fertility declines at an increasing rate after age 35. For this reason, some patients consider freezing their eggs if they expect a delay in starting a family, in order to provide more options in the future if spontaneous conception is not possible.
Who is a candidate for Egg Freezing and when are the eggs used?
Once the eggs are collected they are cryopreserved in liquid nitrogen. While they can remain frozen indefinitely, it is recommended that the patient uses them before age 50, which is the natural age of menopause. Patients should consider the risks of pregnancy at advanced maternal age (over 35), including gestational diabetes, preeclampsia, c-section delivery, preterm delivery, and low birth weight when deciding on a timeframe for using their eggs.
If the patient is over 50, or if other health conditions prevent pregnancy when they choose to use their frozen eggs, they can use a gestational carrier.
How successful is Egg Freezing?
While egg freezing may be successful, there is a risk that eggs might not survive the freezing and warming process. International studies suggest that the survival rates vary from 80-90% per egg. Only good to excellent quality eggs are vitrified in order to achieve this survival rate.
Eggs could survive the vitrification and warming process, but might be damaged during the process, making them unsuitable for insemination. It is recommended that intracytoplasmic sperm injection (ICSI) is used to inseminate the eggs. International studies suggest the chance of successful insemination of cryopreserved and warmed eggs using ICSI is 70-80% per egg. Vitrified eggs yield fewer embryos than fresh eggs. Studies show that there is almost double the blastocyst rate with fresh eggs versus frozen eggs.
There is very limited data on live birth rates after social egg freezing, but existing data suggests similar clinical pregnancy rates after transfer of embryos obtained by either frozen or fresh eggs. More than one cycle may be required to obtain the number of mature eggs that are desired. The table below provides information on cumulative live birth rate by age of egg provider:
The drugs used to stimulate the ovaries can result in ovarian hyperstimulation syndrome (OHSS) in 1-3% of cases. This is a potential serious complication and more information can be found on the OHSS information page. If this appears likely to occur, treatment may have to be cancelled.
The egg retrieval is an outpatient procedure. As with any procedure, some risk is involved. It may include discomfort associated with aspiration of the follicles. There is a slight chance of bleeding or pelvic infection. This occurs in less than 1% of cases.
Our Egg Freezing patient information brochure provides more information on risks and the procedure.