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These are the most common technologies
that are available to those who are undergoing In Vitro Fertilization
(IVF)
IVF Protocols
One is usually placed on birth control
pills to regulate their cycles. Lupron may be added at this time
depending on the protocol your RE chooses. Once you stop the
pill, injectable gonadotropins will be used to stimulate as many
eggs as safely as possible. One will have transvaginal ultrasounds
performed to monitor the growth of the follicles, usually about
3-5 times once the birth control pills are stopped. Once the
lead follicles reach a size of around 18-22mm, then the hCG trigger
will be given. About 35 hrs after the trigger, you will be taken
to a surgical suite, and using the same transvaginal ultrasound,
a needle (same type used to draw blood, but longer) is "poked" through
the vagina (with the ultrasound probe looking straight into the
ovary) and the needle placed directly into the follicle. Under
suction, the contents of the follicle are removed and go into
a test tube (hence the old name "test tube babies").
The eggs are taken out of the test tubes and placed into a Petri
Dish where the sperm are placed with the egg for fertilization.
The embryos are incubated for 3-5 days. The resulting embryos
on a daily basis are checked to make sure theyre diving properly
and "graded". At the day of transfer, depending on
the embryos cellular division and quality, your RE and you will
decide how many will be transferred back.
The embryos are placed into a catheter,
the RE will then place a speculum just like a pap smear, the
catheter containing the embryos are passed through the cervix
and into the uterus where they're deposited. Progesterone and
Estrogen will be taken thereafter and a blood hCG level is drawn
about 12 days after egg retrieval.
Intracytoplasmic Sperm Injection
(ICSI)
is a procedure in which a single sperm
is isolated and directly injected into the egg, creating fertilization.
This technique was revolution when finally mastered in the late
1990s. Prior to this, men who produced few sperm or sperm with
low morphology (shape) or motility (swimmers), required donor
sperm since their sperm may not have had the capacity of burrowing
through the eggs shell appropriately. With ICSI, we dont have
to worry about burrowing through the eggs shell, as a syringe
will contain a single sperm and this is directly injected into
the egg and as stated above, fertilization is achieved.
Egg freezing (Oocyte Cryopreservation)
C.A.R.E
fertility is also proud to announce that it will provide
egg freezing with IRB approval from GAMC as recommended by
the American Society for Reproductive Medicine (ASRM).
Eggs (Oocyte) are placed on a special freezing
environment. They can remain frozen for months or even years,
and can be thawed for use in IVF in the future.
Testicular Sperm Extraction (TESE)
Usually performed by a Urologist who specializes
in Male Fertility. Approximately 40% of men who produce no sperm
have some sort of tubal obstruction (yep, sperm have to pass
through a series of pipes to be ejaculated) usually in the Vas
Deference. Men who have had hernia repairs are usually at high
risk for having obstructions created from surgery. Some men,
especially those with mild forms of Cystic Fibrosis are born
without the Vas Deference (partner testing will be required).
In these cases, there is usually ample sperm in the testis (epididymis).
A Urologist can simply extract sperm directly from the testis
with a special syringe. The eggs extracted from IVF can then
be fertilized via ICSI using these sperm.
Assisted Hatching (AH)
Embryos sometimes have shells that surround
them that look very thick. We believe that these thickened shells
may not allow the embryo to hatch sometimes, which wouldnt allow
for implantation and pregnancy. These thickened shells are notoriously
encountered in Poor Responders and in women over the age of 38.
The shell can be thinned out either with a laser or an acid solution
to make it easier for the embryo to hatch.
Preimplantation Genetic Diagnosis
(PGD)
A procedure where a specific genetic defect
can be determined in embryos. A Day 3 embryo usually has 8 cells
and one of these cells is extracted and analyzed for the specific
defect. For example, a couple both are carriers for Cystic Fibrosis
(CF), meaning they are at high risk for passing CF to their children.
The cell that was extracted from the embryo is analyzed for CF,
and if the cell doesnt have this genetic defect, it is assumed
the embryo does not and vice versa. Only those embryos that had
the normal cells would then be transferred back into the uterus
to allow implantation and pregnancy to occur with a non-afflicted
baby.
Nowadays, sometimes when a family has a
child that has a certain type of leukemia and there is no one
in the family with a bone marrow match, couples may undergo IVF
+ PGD to specifically look for an embryo that will carry a bone
marrow match. Once the embryo(s) are identified, these embryos
are transferred back. Once this baby is born, a small sample
of the babys bone marrow is taken to save his/her siblings life
from leukemia.
Preimplantation Genetic Screening
(PGS)
A procedure in which couples simply want
to make sure the embryos being transferred back are chromosomally
normal. The biopsy can either be performed on Day 3 or Day 5
blastocysts (embryo). The advantage of doing a day 5 trophoectoderm
biopsy is that multiple cells (not just one that is done on Day
3) can be biopsied, usually from the area of the blastocysts
that is destined to be the placenta. Presently, there are two
ways to screen embryos, either through Flourescent In-Situ Hybridization
(FISH) or Comparative Genetic Hybridization (CGH). FISH can not
check all of the chromosomes, so only a few are checked. CGH
can check all 46 (including sex) chromosomes and is becoming
commercially available. Both of these procedures only check for
the number of chromosomes, which can avoid genetic defects such
as Downs Syndrome. With a Day 3 transfer, the resulting fresh
blastocyst can be transferred back fresh on Day 5. If one desires
to do CGH, the biopsied embryo must presently be frozen because
it takes a few weeks to get the results back. Then, the normal
embryos are thawed and transferred back. As several articles
are pointing out however, the biopsied cells that are being screened
with these two technologies are not necessarily representative
of the cell itself. Some abnormal embryos seem to self-correct
and become normal babies and vice versa. Pregnancy rates also
appear to be lower when the embryos are biopsied like this. Although
CGH is more complete than FISH for checking chromosomes, CGH
is in its infancy and requires at present the freezing of the
biopsied blastocyst with eventual thawing of the normal blastocyst
for transfer. At present, PGS remains controversial in the fertility
world, and is not presently recommended by the community for
simple screening purposes.
Microarray Chips are presently under scientific
investigation in which several hundreds of genes (not just the
chromosome number) can be evaluated in each embryo. Lethal and/or
debilitating genes found in embryos can primarily be evaluated
and only those that do not carry these genes can be transferred,
but this technology is still a few years away from being commercially
available.
There are still many more technologies
being developed, such as finding embryo markers in culture media
that by simply checking the media and not manipulating the embryo,
we may be able to determine the best embryo. Others are studying
flow dynamics to try and mimic the fallopian tube environment
for the embryo. Whereas these make sense, we are hopeful that
within a few years, we will be able to provide these technologies
to you to not only improve pregnancy rates, but to also provide
diagnosis when needed. |
