I am Dr. Christine Briton-Jones, I am the
Director of Laboratory Services here at RMA of New York, and here at RMA, we are very
serious about doing the best that we can do, & the way we do that, we stick strictly to
the ASRM guidelines, American Society for Reproductive Medicine, we also report to the
Society of Assisted Reproductive Technology, and also to the Center for Disease Control.
But rather than tell you about it, I’d rather show you. So let’s begin in the lab. Vitrification is a technique used to preserve
a woman’s eggs that has revolutionized fertility preservation. The term vitrification, comes
from the latin word vitrum, meaning glass. When eggs are vitrified, they are cooled so
quickly that they are transformed into a glass-like state. Prior to the use of vitrification,
eggs were routinely preserved by slow freezing. The biggest drawback of the slow-freezing
method is the formation of ice crystals during cooling which can irreparably damage the egg’s
cell membrane. Vitrification is successful largely because it doesn’t allow for ice
crystal formation. On the day of the egg freezing procedure, a reproductive endocrinologist
retrieves the eggs using ultrasound guidance. The fluid from each follicle is aspirated
into a test tube, and brought into the embryology lab. An embryologist pours the fluid into
a dish to search for the egg. The egg is readily apparent, because it is surrounded by a mass
of clear-looking cumulus cells. The egg is picked up with a pipette and placed in a culture
dish labeled with the patient’s name. At the end of the egg retrieval the culture dish
containing all the eggs is placed in an incubator until the freezing procedure is ready to begin.
Only the eggs which have completed the maturation process are capable of being fertilized by
a sperm so it is important to evaluate the maturity of the egg prior to freezing. This
evaluation requires the removal of the cumulus cells surrounding the egg by repeated pipetting,
and observation of the egg under high magnification. The eggs determined to be mature are now ready
to be frozen. The first step of the vitrification procedure
is to move the eggs through a series of solutions, each for a specific duration, to gradually
remove water from the eggs. The water needs to be removed to avoid ice crystal formation.
As the water is removed the eggs visibly shrink; the solution also contains a cryoprotectant,
which penetrates the egg’s cell membrane to replace the removed water. The cryoprotectant
acts like anti-freeze to protect the egg during vitrification.
The final step is to place the eggs on a specialized vitrification device in a very small volume
of media. The vitrification device is labeled with the patient information and witnessed
by a second embryologist. Vitrification occurs as the device containing the eggs is plunged
into liquid nitrogen. The eggs are cooled at an ultra-rapid rate, to negative one hundred
and ninety six degrees Celsius, and the media drop containing the eggs is transformed into
a glass-like bead. The device is then placed in a labeled goblet
on a labeled cane for secure storage. Each cane contains the eggs of only one patient.
The patient’s cane is then placed in a long term storage container filled with liquid
nitrogen called a dewar, which is equipped with a 24 hour a day, 7 day a week alarm monitoring
system to indicate any change in temperature. When maintained at this extremely low temperature,
eggs can theoretically be kept indefinitely, until the patient is ready to use them. At RMA of New York, we take great pride in
helping our patients and facilitating their family-planning goals. The technological advancement
represented by vitrification has provided remarkable success rates, and several large
corporations have even begun to offer health benefit coverage for egg freezing treatments.
Even though our abilities are consistantly improving, RMA of New York is not able to
guarantee any specific results. Though we exercise extreme diligence in performing this
procedure, we are not able to provide assurances that your eggs will survive the freezing and
thawing procedure, that after thawing they will fertilize successfully or normally, that
after fertilization they will successfully implant or that after implantation they will
develop into embryos or result in healthy offspring. We hope that by providing this video we have
given you a more comprehensive understanding of the egg freezing process.