"shelf-life" of frozen embryos
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I'm just curious how long one has to use frozen embryos without substantially decreasing the chances of a healthy live birth resulting after thaw and transfer. (Has this "shelf-life" changed much over the years? Have freezing/thawing techniques improved over the years?)
Do you know the longest amount of time an embryo that has given rise to a healthy live birth has been frozen before being thawed and transferred?
Thanks.
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Embryos do not have a "shelf life". As long as they remain frozen in liquid nitrogen (-196 degrees C), they will be fine.
Freezing and thawing techniques for Day 1 and Day 3 embryos have chaged little over the past 20 years. Blastocyst freezing has been around for about 15 years with the current (more successful technique) having been used for about 10 years.
There is a new technique on the horizon called vitrofication. Some people are using it now, but the jury is still out as to whether of not its better than the traditional methods. We'll see.
I recall reading a press release several years back of the a successful thawing, transfer and pregnancy resulting from embryos that had been frozen for 8 years. There may have been more recent reports with a longer period.
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