Patients
are often confused about whether the success rate with fresh embryo transfer is
better or worse as compared to frozen embryo transfer . Let me put this in
perspective .
There
used to be a time when our ability to freeze embryos was poor , as a result of
which many of them died during the lab
process of freezing and thawing them. This is why in the early days of IVF, the
pregnancy rate with fresh embryos was better – and this is still true when the
IVF lab is not good, and the embryologist doesn’t have the expertise and
experience to freeze embryos properly.
However,
with the technique of ultra-rapid freezing ( vitrification ), the survival rate
of frozen embryos after thawing is nearly 100% in a good clinic .
After
all, don’t forget that before we transfer the frozen embryo ( which is at
-196 C), we need to thaw it to 37 C – so it’s exactly like a fresh embryo when we
transfer it.
However,
if the endometrial lining is not ready , or the patient is at risk for ovarian
hyperstimulation syndrome ( OHSS), it’s far better to freeze all the embryos .
This is where the actual value of freezing comes in.
The other
big advantage of freezing is that you only need to transfer a single embryo at a
time, which means the patient doesn't run
the risk of a multiple pregnancy , with the consequent risk of prematurity and
cerebral palsy in the babies .
However
, do remember that freezing is a good option only when you are sure that the
lab is technically competent , and does only blastocyst transfers .
Now,
if the embryologist is not confident about his own skills , and cannot be sure
they can grow embryos routinely to Day 5 in their lab , then why would you
trust them to be able to freeze and thaw your embryos properly ?
If
you freeze your embryos in a bad IVF lab, there is a very real risk that the embryos
will die as a result of this, and the freezing and thawing will reduce your
pregnancy rates .
Sadly,
most patients are completely clueless about these risks . Not only do they refuse
to take the time and trouble to understand the details, doctors are often very opaque
, and will not share this information with the patient .
This
is why patients aren’t able to can’t make well informed decisions , and they
get suboptimal care.
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