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In vitro fertilization (IVF) and other "high tech"
procedures are now referred to as the assisted reproductive
technologies (ART). These procedures all involve collecting the
oocytes (eggs) and placing them in direct contact with sperm.
Together they form an alphabet soup of techniques including: IVF,
GIFT, ZIFT, ICSI, and FET.
In its simplest term, IVF is simply the uniting of
egg and sperm in vitro (in the lab). Subsequently the embryos are
transferred into the uterus through the cervix and pregnancy is
allowed to begin. IVF was the first of the ART techniques to be
developed. The first birth was in 1978 in England. The procedure
was pioneered by a Gynecologist and a Ph.D. (Drs. Steptoe and
Edwards). Next came GIFT, which stands for gamete (egg and sperm)
intrafallopian transfer. This procedure requires laparoscopy,
which is a small incision surgery and requires a general
anesthetic. With existing technology, pregnancy rates are similar
with IVF and GIFT. Since IVF does not require surgery, it has
supplanted GIFT.
ZIFT involves IVF and then a laparoscopic surgical
procedure to transfer the embryos into the fallopian tube. Since
transferring embryos through the cervix with IVF gives the same
pregnancy rate as ZIFT, and is nonsurgical, IVF has also
supplanted GIFT.
As the years have passed, IVF has become the
dominant ART technology due to its simplicity, efficacy and lack
of invasiveness. A typical IVF cycle begins with shutting down the
ovaries. This is done with a medication known as a GnRH agonist.
The most common drug such used is Lupron. Lupron is given for
approximately two weeks after which the ovaries are shut down
temporarily. The next phase involves stimulation of the ovaries
with potent ovulation medications such as Pergonal. For a full
description of these agents go to the page on ovulation
medication. These injections are given for approximately 10 days.
When the eggs are ready for harvesting, a final step is to give
hCG to induce final maturation. The eggs are then harvested by a
process called ultrasound guided vaginal retrieval. Under heavy
sedation, and with ultrasound guidance, a thin needle is passed a
short distance into the ovaries and the eggs are suctioned from
the follicles. Typically 5-15 eggs are collected. Typically the
eggs are fertilized by adding approximately 100,000 motile sperm
to each egg. If the sperm will not fertilize the eggs naturally we
can perform intracytoplasmic sperm injection (ICSI). This
procedure involves puncturing the egg directly under a microscope
and injecting one sperm in the egg.
The day following retrieval, we can document
fertilization under the microscope. We then observe the embryos
for 3-6 days. The current trend is to observe longer. Typically
3-4 embryos are then placed in a catheter and transferred through
the cervix into the uterus. This is a simple procedure much like a
Pap smear. At the present time, embryos can be transferred either
3 or six days following retrieval. A 3-day embryo is usually at
the 6-8-cell stage.
Two weeks later a pregnancy test can be obtained.
Two weeks after the pregnancy test, an ultrasound can be performed
and the fetal hear beat can be seen. If more embryos were
generated than can be replaced, freezing (cryopreservation) can
save these additional embryos. Frozen embryos can be stored for
future replacement at much lower cost than the original IVF cycle.
As the years have passed, IVF has improved
greatly. Today it is arguably the most effective technique to
treat infertility when compared with others on a month by month
basis. IVF has created a lot of controversy also. First, it is
expensive. An IVF cycle can cost $6,000 to $7,000. It may not work
on the first cycle. Multiple pregnancies can result. The truth is
that it is a powerful technology and must be used carefully. Some
patients may have very high odds of success: 45 - 60% chance per
attempt. Others may due to their situation have only a 20% chance
of success.
The multiple pregnancy risk varies with age.
Younger patients need fewer embryos to be replaced, and older
patients need more. The worst thing that has happened with IVF is
the various centers entering into a race to see who can get "the
best statistics". This has encouraged centers to transfer high
numbers of embryos to get the statistics while accepting too high
a risk of multiple pregnancy.
Also in order to get the best statistics, some
patients will be refused care in order to "protect the
statistics".
f) cells, trigger a local or widespread
inflammatory response, and retain the memory of the offending
organism to repel it again if it should ever return. Like any
finely-tuned machine, however, the system can break down and leave
us open to the threat of infection, or, conversely, turn against
our own healthy tissues, as occurs in such diseases as rheumatoid
arthritis or lupus.
The immune system also plays an important role in human
reproduction. Inflammatory cells and their secretory products are
involved in the processes of ovulation and preparation of the
endometrium for implantation of a fertilized egg. Dysfunction of
the immune system can interfere with the normal reproductive
processes and result in infertility. It has been estimated that an
immune factor may be involved in up to 20% of couples with
otherwise unexplained infertility. Although many of these
associations with infertility remain unproven, there is solid
scientific evidence to implicate the formation of antibodies
against sperm as an important infertility factor.
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