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Thursday, February 23, 2011 – San Francisco, CA –Embryologists at Laurel Fertility Care are using vitrification, the latest method for freezing unfertilized eggs, to preserve fertility options for patients. “This cutting edge practice is still fairly new and not many programs are doing it,” commented Laurel Fertility Care Lab Director Dr. Marlane Angle, PhD. “However, survival rates using vitrification are much higher for eggs and embryos when compared to previous freezing methods like slow cooling.”

Why Choose Vitrification? 

“It's the technology of the future,” commented Dr. Angle. “People, especially women, need this and are asking for it. On average we see four types of people requesting vitrification. The women we were originally concerned about were women undergoing cancer treatment. These women often experience fertility challenges following radiation or chemotherapy. If these women preserve their fertility before cancer treatment, they have a much better chance of conception down the road” However, according to American Society of Clinic Oncology, less than 25% of oncologists refer patients to a fertility specialist, leaving many patients unaware of their options.[1]

Even if a woman isn’t going through a life threatening process like chemotherapy, vitrification is still a great option. “The second group of patients for whom freezing eggs is a great option are those women who are really invested in their careers, are nervous that they might not find that right person, or feel like the clock is ticking.” observed Dr. Angle. “Women have a much better chance of getting pregnant at age 25 verses age 35 and age 35 verses age 40. Preserving your fertility at an early age will provide options ahead.”

Another group that often requests egg vitrification includes patients for whom there is no sperm available, whether this means that male partner is unable to produce sperm on the day that it is required or because the patient has no male partner. Freezing women’s eggs allows time and flexibility to get sperm. Time no longer controls the hopeful parents or contributes additional stress.

The final group that most frequently requests vitrification includes patients who don't want to freeze embryos. Comfort levels can change drastically depending on ethical or moral views and religious practices. Thus, freezing eggs can be less morally conflicting. “Vitrification finally provides people with options to safely preserve parenthood until the time is right.” remarked Dr. Angle, “Becoming proactive now will improve options for parents and the lives of their future children.”

Slow cooling vs. Vitrification

Until recently, options for preserving fertility were limited to slow cooling. Though this process works well for preserving sperm, damaging ice crystals can form inside larger cells, such as eggs. The ice crystals can physically damage the egg during the thawing process. The minimal success rates of slow cooling have pushed scientists like Dr. Angle to use vitrification. “Vitrification reduces the formation of ice crystals found in slow cooling.  Rapidly dropping the temperatures inside of eggs within milliseconds results in cooling the egg to preserve it and by-passes the time required for the formation of ice.” described Dr. Angle, “The very rapid cooling allows us to freeze the egg in its current state.”                                                                                                                                                          

History of Cryopreservation

The idea came from watching nature, specifically frogs and fish. Scientists questioned how Arctic fish could be swimming in and around frozen icebergs, becoming frozen themselves yet live through these conditions. This led to the discovery of cryoprotection, the ability to drop body temperatures quickly enough to preserve the current status. As scientists researched further, they mimicked cryoprotection by developing a slow cooling freezing process. This led to the first successful slow cooling cryopreservation of mice embryos in 1972.[2] Then in 1983, the first human pregnancy was reported after using slow cooling cryopreservation.[3] However, the pregnancy was terminated due to complications during the egg’s development. During this time, researchers Greg Fahy and William Rall reported a new way of cryopreservation, vitrification.[4] Since Fahy and Rall’s discovery of vitrification, multiple studies have shown that survival rates double using vitrification versus slow cooling have doubled.[5]

For more information on vitrification and how it can help preserve your parenting options, please call Laurel Fertility Care at 415.673.9199 or email info@laurelfertility.com  

More Resources and Additional Reading:

MyOncofertility: Fertility education for chemotherapy and radiation recipients

http://myoncofertility.org/

American Society of Reproductive Medicine: Cryopreservation and Storage http://www.reproductivefacts.org/topics/detail.aspx?id=408

Kuć P, Kuczyńska A, Stankiewicz B, Sieczyński P, Matysiak J, Kuczyński W. Folia Histochem Cytobiol. Vitrification vs. slow cooling protocol using embryos cryopreserved in the 5th or 6th day after oocyte retrieval and IVF outcomes. 2010 Jan 1;48(1):84-8. 

 http://www.ncbi.nlm.nih.gov/pubmed/20529821

[1] National survey of physicians practice patterns: Fertility preservation and cancer patients.http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=65&abstractID=33118

[2] Whittingham DG, Leibo SP, Mazur P. Survival of mouse embryos frozen to -196 degrees and -269 degrees C. Science. 1972;178:411-414.

[3] Trounson A, Mohr L. Human pregnancy following cryopreservation, thawing and transfer of an eight-cell embryo. Nature. 1983;305:707-709

[4] Rall WF, Fahy GM. Ice-free cryopreservation of mouse embryos at -196 degrees C by vitrification. Nature. 1985;313: 573-575

[5] Kuć P, Kuczyńska A, Stankiewicz B, Sieczyński P, Matysiak J, Kuczyński W.Vitrification vs. slow cooling protocol using embryos cryopreserved in the 5th or6th day after oocyte retrieval and IVF outcomes. Folia Histochem Cytobiol. 2010 Jan 1;48(1):84-8. PubMed PMID: 20529821.