"New Egg Freezing Technique": What Cancer Patients Should Know
Updated: May 12, 2020
Recent headlines around the world have heralded the arrival of the first baby born through a new egg-freezing technique called in-vitro maturation (IVM).
Due to concerns about ovarian stimulation, a French woman with cancer had immature eggs retrieved from her ovaries prior to undergoing chemotherapy.
Immature eggs are those that have not yet undergone the final stages of chromosomal processing, which usually occurs in the build up to ovulation.
Rather than the eggs maturing in her ovaries, the patient's eggs were matured in the lab using a new technique called in-vitro maturation (IVM) before being frozen.
Five years later, the eggs were thawed, fertilized with sperm, and one embryo was transferred to her womb resulting in the very first child born using this egg freezing technique.
Experts greeted the breakthrough as a positive step for cancer survivors who don't have time to undergo ovarian stimulation prior to chemotherapy.
Now that it has been shown that freezing immature eggs can lead to a healthy birth down the line, the natural question to ask is: could women undergoing fertility treatments like egg freezing and IVF skip the expensive and uncomfortable process of ovarian stimulation, which involves injecting a series of hormones needed to mature multiple eggs inside the ovaries? Or, could patients undergoing fertility treatment skip straight to the retrieval procedure?
Below, we ask a top specialist fertility doctor for her views on this.
But first, here's some more background on the egg freezing treatment received by the patient in question...
Why was in-vitro maturation used?
When a 29-year-old cancer patient living near Paris decided she wanted to take action to preserve her fertility prior to chemotherapy, doctors at Antoine Béclère University hospital ruled out standard egg freezing practices where the ovaries are stimulated with hormones due to concerns that it might exacerbate her cancer.
One option was to remove and freeze some of her ovarian tissue and re-graft it once she recovered from chemo (also considered a new and controversial treatment), but the patient considered the operation too invasive. Instead, she opted to have her immature eggs retrieved without any of the traditional hormone injections in the hopes that the lab would be able to mature them in a petri dish before having them frozen.
The patient recovered from cancer, but the same treatment that was able to eliminate her cancer cells also seems to have damaged her fertility.
At age 34, she decided to move forward with fertility treatment, so the team of doctors thawed seven of her lab-matured frozen eggs, six of which survived the process. Then, they were fertilized with sperm using a technique called intracytoplasmic sperm injection (ICSI). Only one of the eggs developed into the healthy embryo. From that embryo, the patient got pregnant and gave birth to a healthy baby boy named Jules.
What implications does this have?
Is this a new procedure?
"It is interesting," says Dr. Givens. "But the novelty is in combining several already-established procedures: immature egg recovery from a non-stimulated woman, then, in vitro maturation (IVM). From there on, the actual vitrification (freezing), thawing and fertilization follows the same process."
There have been previous live births from eggs have been matured in the lab before. But this was the first birth from an egg matured in the lab that was frozen before later use.
What are the benefits?
"The novelty is the avoidance of stimulation (hormone injections), and the lack of delay in starting chemotherapy in what I am guessing is a woman with estrogen-receptor positive breast cancer," she says. "You’d really have to have a lot of data to show that this process improves (egg) survival over what we do now for women with this time - which is to stimulate the ovaries, but keep their estrogen levels low."
A cancer is called estrogen-receptor-positive (or ER+) if it has receptors for estrogen. These cancer cells, like normal breast cells, may receive growth-promoting signals from estrogen.
"Currently, at most, the delay to starting chemotherapy is 2-3 weeks. There is a lot of data showing that women that freeze eggs or embryos prior to chemo are not negatively impacted by this approach, vis-à-vis their cancer survival."
What are the downsides?
"Immature egg recovery is technically difficult because you are essentially doing an egg retrieval on small, antral follicles," says Dr. Givens. "Although this is still an invasive procedure, it is arguably not quite as invasive as a laparoscopy to recover ovarian tissue for freezing. However, it is still invasive."
Removing and freezing ovarian tissue before chemotherapy can be a more reliable approach, but in addition to being an invasive operation, there is also the risk of cancer cells being present in the ovarian tissue that is removed for storage before chemotherapy, which could be reintroduced in the graft.
"IVM has been around for many years now but not really catching on because it is inefficient and, like time-lapse videography of embryos, a technology looking for an application."
Essentially, the process of using culturing immature eggs in the lab is not very efficient, so in most cases a different method will be better.
"As they said, she was very lucky to get one embryo." - Dr. Carolyn Givens
Could this be used more widely now?
The general fertility preservation treatment plans for both cancer patients and those undergoing egg freezing for other reasons are unlikely to change to this technique. The process requires a different set of skills to normal IVF, so it isn't widely available, and maturing eggs outside the ovaries is a challenging process.
As fertility preservation expert Professor Michaël Grynberg, who led the project said:
"We are aware that eggs matured in the lab are of lower quality when compared to those obtained after ovarian stimulation...However, our success with Jules shows that this technique should be considered a viable option for female fertility preservation, ideally combined with ovarian tissue cryopreservation as well."
For now, this "new" technique is unlikely to become a mainstream treatment option for healthy women. However, it may allow some women - in particular, those with cancer - an extra option when others are not possible, or when time is short.
What's more, it marks a step forward in terms of skills and developing further fertility preservation techniques.
Professor Richard Anderson of the University of Edinburgh and expert panelist on the book Everything Egg Freezing, says: "This advance is particularly important for cancer patients, but it's also a step towards easier and less invasive IVF for other women and couples needing assisted reproduction."
Find more information about the process of deciding to egg freeze, what the procedure involves and how to prepare physically and emotionally in Everything Egg Freezing: The Essential Step-by-Step Guide to Doing it Right.