ABOUT IVF
In vitro fertilization (IVF) is a treatment option
used for couples with infertility that cannot be treated using simpler
methods. This procedure has excellent success rate but requires
significant effort and can be expensive. For all of these reasons,
advanced treatment options can be stressful. These natural stresses can
be minimized if you understand the nuances of the various procedures.
Understanding the applications for each procedure will help you obtain
the appropriate treatment and maximize your chance for success.
Step One - Ovulation Induction
Hormone injections are given to stimulate multiple
egg production. This is because the normal cycle usually produces one
egg only, and pregnancy rates in IVF are better if a number of eggs can
be collected. These injections are usually given subcutaneously (under
the skin) and are much less uncomfortable than the previous generations
of medication. We then monitor the progress of ovulation induction with
ultrasounds and blood estrogen levels over several days.
Step Two - Egg Retrieval
An egg retrieval is performed by placing a special
needle into the ovarian follicle and removing the fluid that contains
the egg. This is a relatively minor procedure and is performed by
visualizing the follicles with a vaginal ultrasound probe. A needle is
directed alongside the probe, through the vaginal wall, and into the
ovary. To avoid any discomfort, strong, short acting intravenous
sedation is provided.
Step Three - Fertilization and Embryo
Culture
Once the follicular fluid is removed from the
follicle, the eggs are identified by the embryologist and placed into
an inubator. The eggs are fertilized with sperm later that day by
conventional insemination or by Intracytoplasmic Sperm Injection
(ICSI).
During conventional insemination approximately
50,000 sperm are placed with each egg in a culture dish and left
together overnight to undergo the fertilization process. The ICSI
technique is used to fertilize mature eggs in the event of sperm or egg
abnormalities. Under the microscope, the embryologist picks up a single
sperm and injects it directly into the cytoplasm of the egg using a
small glass needle.
ICSI allows couples with very low sperm counts or
poor quality sperm to achieve fertilization and pregnancy rates equal
to traditional IVF. It is also recommended for couples who have not
achieved fertilization in prior IVF attempts. Special urological
procedures are available to you for cases where it is difficult to
obtain sperm or for men with no sperm in the ejaculate.
The eggs will be checked the following day to
document fertilization and again the next day to evaluate for early
cell division. They are now called embryos and are placed in a solution
called media to promote growth. Until recently, embryos were cultured
for three days and then transferred to the uterus and/or cryopreserved
(frozen). We now have the ability to grow the embryos for five or six
days until they reach the blastocyst stage. For some couples these
blastocysts may have a greater chance of implantation, allowing us to
transfer fewer embryos and lower the risk of multiple birth while
increasing the chance of pregnancy.
On day two or three after fertilization, the
embryos will be evaluated for blastocyst culture. If there is a
sufficient number of dividing embryos they will be placed in special
blastocyst media and grown for two or three additional days.
Step Four - Embryo Transfer
Embryos may be transferred on day 3, 5, or 6 after
egg retrieval. Transfers on day 5 or 6 are called Blastocyst Transfers.
They are placed through the cervix into the uterine cavity using a
small, soft catheter. This procedure usually requires no anesthesia. It
is similar to the Mock Embryo Transfer which will be performed prior to
the actual IVF cycle.
Additional Advanced Technologies
Assisted Hatching
-
(AH) is a procedure performed prior to transfer
in selected cases. An embryo needs to escape or "hatch" from it's
protein shell, called the Zona Pellucida, before it can implant in the
uterus. In AH, a chemical or a laser can be used to dissolve part of
the zona, to facilitate the hatching process later. This technique is
often used with prior failed IVF cycles, female age over 38, and with
abnormally thick zonae.
Percutaneous Epidydimal Sperm Aspiration and
Testicular Sperm Extraction (PESA and TESE)
-
Some men have no sperm in the ejaculate but
still produce them in the testes. This may occur due to a vasectomy, to
a congenital obstruction of the sperm ducts leaving the testes, or to
inadequate development of the sperm such that they cannot leave the
testes. In these situations, a urologist can remove sperm by placing a
needle into the testis or the tubes that drain it. These procedures are
done under anesthesia and can be very effective when combined with
ICSI.
Cryopreservation
-
Embryos that are not transferred but continue
to thrive in the laboratory can be cryopreserved (frozen). We recommend
freezing for any high quality embryos that survive to the blastocyst
stage. These embryos are stored in liquid nitrogen and can be thawed at
a later date. While the pregnancy rates with frozen embryos are not as
high, the procedures involved in preparing for a frozen embryo transfer
are much simpler and less expensive. Freezing only embryos that survive
to the blastocyst stage maximizes the chance for success in a thaw
cycle.
Preimplantation Genetic Diagnosis (PGD)
-
Genetic testing on preimplantation embryos may
be indicated for patients who are at risk for genetic disorders such as
Cystic fibrosis or Thalassemia and for patients with infertility
related to chromosomal abnor-malities such as recurrent pregnancy loss
or repeated unsuccessful IVF.
Egg Donation
-
In many situations, especially when a female
patient is in her late 30's and early 40's, infertility may result from
a decrease in ovarian function and a consequent fall in egg quality. In
the event of a severe compromise in ovarian function, successful
pregnancy is very unlikely. A treatment that often offers an excellent
chance of success is to use eggs from a donor who is capable of
producing good quality eggs. This is a complex treatment option from
medical, psychological and ethical viewpoints, but one that provides a
very good chance for pregnancy.