VITRO FERTILIZATION (IVF)
ASSESSMENT & PROCEDURES
Prior to initiating an IVF cycle, screening tests can predict how well the
wife's ovulation will respond in an IVF cycle as well as determine if there
are any abnormalities that may preclude IVF from being successful. These
screening tests and procedures include:
- The uterine cavity is evaluated by either a hysterosalpingogram
(dye test performed in radiology), a special type of ultrasound evaluation
(sonar insufflation study [SIS] ), or by looking into the uterus with
a small telescope (hysteroscopy). These types of evaluations make sure
that there are no intrauterine abnormalities such as polyps or fibroids
that may interrupt implantation of the embryo. If an abnormality is
found, it may be necessary to surgically correct the abnormality before
proceeding with an in vitro fertilization cycle.
- A Clomid Challenge Test is a dynamic test that is used for assessing
the status of eggs that are remaining in the ovary, as well as to help
establish the best medication regimen for stimulating egg production
in an in vitro fertilization cycle. If levels are abnormal, the prognosis
for success with in vitro fertilization is extremely poor and you may
not be a candidate for in vitro fertilization.
- An autoimmune profile including antinuclear antibody levels (ANA),
thyroid antibodies (TAG), lupus anticoagulant screen (LAC), and anticardiolipins
antibody levels (ACL) are routinely obtained prior to undergoing an
IVF cycle. If these levels are abnormal, this could indicate a sensitized
immune system that may result in poor embryo implantation or arrested
- When treating male infertility, we must be able to obtain an adequate
number of sperm. Also, we must take steps to rule out any infection
in a man's seminal fluid that may interfere with fertilization, embryo
growth and embryo implantation.
During IVF, we must be able to control the timing of the egg release from
the ovaries. We must also increase the chance of collecting more than
one egg. To do this, we use special drugs to stimulate the ovaries. We
then use an ultrasound scanner (it takes a picture from sound waves, like
a submarine's sonar) to keep track of the development of follicles (the
structures on the ovary that contain the eggs). We will also be taking
blood samples to monitor hormone levels. We will use this information
to calculate the timing of the egg release. When the time is right, the
wife receives an injection of HCG (human
chorionic gonadotropin). This substance induces the follicles to undergo
their final maturation and prepares the egg(s) for release and collection.
On the last day of stimulation, an ultrasound evaluation of the endometrium
(lining of the uterus) will be performed. In rare cases, the lining may
not develop adequately. In this circumstance, cryopreservation and return
of the embryos to a more normal appearing endometrium may be suggested.
Although we will know the appropriate number of maturing follicles on
your ovaries from our ultrasound scan, we will not always be able to determine
the number of eggs you will produce for collection. There currently is
not a guaranteed method for assessing and harvesting eggs; therefore,
in rare cases, no eggs are retrieved. In the average case, eight to twelve
eggs may be obtained.
We use a technique called "ultrasound guided aspiration" to
retrieve mature eggs from the follicles which requires the use of intravenous
sedation. Ultrasound guided aspiration allows us to remove the follicle
fluid containing the eggs. This procedure must be performed at exactly
the right time. If the egg is collected too early, it will not develop
properly and might fail to fertilize. If we delay the procedure too long,
the egg may be released from the follicle and lost. Unfortunately, not
every follicle contains an egg. Also, many eggs are not healthy, and some
will fail to fertilize for no apparent reason.
When the fluid is removed from your follicles, it is taken to the laboratory
where the embryologist identifies the egg(s) and places it in a special
substance called culture medium.
The husband will be asked to collect a sample for insemination
after the eggs have been retrieved. Many men have collected in our office
or a doctor's office before and feel that collection will not be a problem.
Should you feel uncomfortable with the concept of office collection, we
can arrange for a home collection before or after the retrieval if you
notify us. The sample must be received within 45 minutes of collection.
The best chance of avoiding a problem with collection is to assess your
issues and plan for alternatives. Please feel free to discuss these issues
with your doctor or the IVF nurse coordinator.
The semen is then processed to allow us to select and concentrate the
most active sperm cells. After the eggs are collected and the sperm sample
has been received and prepared, we then place these active sperm and the
eggs inside an incubator where fertilization takes place and the embryo
begins to develop. If ICSI
(intracytoplasmic sperm injection) is required, it will be performed
at this time.
CULTURE AND FERTILIZATION
Our embryologist(s) examine the culture at regular intervals to make sure
fertilization has taken place and the embryo is dividing properly. Normal
fertilization (70-75%) is evident by the presence of two pronuclei; genetic
material from one egg and one sperm. In some cases, abnormal fertilization
may occur (5-7%) as evidenced by the presence of more or less than two
pronuclei. Micromanipulation (ICSI)
may be indicated in a subsequent IVF cycle in cases of poor fertilization.
After assessment of embryo growth, the healthiest appearing embryos are
transferred to the wife's uterus, unless blastocyst culture is used. This
usually happens on the third day after the eggs are collected.
After assessment of embryo growth, the embryos that have the best
appearance) are transferred to the wife's uterus. This usually happens
on the second or third day after the eggs are collected, unless blastocyst
culture is used.
Embryo transfer is simpler than egg retrieval.
You will need no anesthetic. We will use a speculum inserted in the vagina
to look for the opening of the uterus. Then, a very thin plastic tube,
called a catheter, carrying the embryo(s) will be gently guided through
the cervix into the uterus. The embryo(s) passes from the tube to the
top of the uterus. You will be asked to lie flat for thirty minutes and
then you may return home. You will be given instructions regarding medication
such as progesterone support.
Culture of embryos to the blastocyst stage
may be used under certain circumstances. Where there are a large number
of good quality embryos, they may be cultured two additional days to day
5, the blastocyst stage, to allow better selection prior to embryo transfer.
In the case of a fresh transfer, only two blastocysts are transferred to
women under 38 due to the higher chance of pregnancy from day 5 embryos
(up to 30-40% for each embryo.) Additional blastocysts can be stored with
cryopreservation for later cycles.
For patients desiring cryopreservation who
have more than the desired number of embryos on day 3, additional embryos
will be cultured to blastocyst stage. This involves culturing the excess
embryos remaining after transfer to day 5 to allow natural selection to
occur. Please be aware that about one in three to four patients will achieve
cryopreservation of one or more blastocyst(s). Blastocyst culture of excess
embryos is routinely performed unless otherwise indicated.
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