What is embryo cryopreservation?
Most
women who undergo hormonal stimulation for an IVF or related
procedure of assisted reproduction produce more eggs than
necessary for transfer during that cycle. The extra fertilized
eggs may be frozen or "cryopreserved" and stored
for future transfer into the infertile woman if she does not
achieve pregnancy initially. Even if pregnancy is achieved
during the initial stimulated cycle, the couple can choose
to transfer the extra frozen embryos even several years later
in order to become pregnant again.
Unfortunately the process of freezing embryos has not been
fully perfected. As many as one-half of embryos may not survive
the thawing process. However, it is important to understand
that the use of thawed frozen embryos offers an important
avenue for achieving conception months, even years, after
the initial egg retrieval. In general, fertilized eggs may
be frozen in our program for a period not exceeding seven
years.
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