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About In Vitro Fertilization
in vitro fertilization , technique for conception of a human embryo
outside the mother's body. Several ova , or eggs, are removed from the
mother's body and placed in special laboratory culture dishes (Petri
dishes); sperm from the father are then added, or in many cases a sperm is
injected directly into an ovum, a process known as intracytoplasmic
sperm injection. If fertilization is successful, a fertilized ovum
(or several fertilized ova), after undergoing several cell divisions, is
either transferred to the mother's or a surrogate mother's body for normal
development in the uterus, or frozen for later implantation. Eggs also can
be frozen and fertilized later. In vitro maturation is when the ova are
extracted and then matured in a laboratory (instead of in the mother's
body) before they are fertilized.
First developed by Patrick C. Steptoe and Robert G. Edwards of Great
Britain (where the first "test-tube baby" was born under their care in
1978), the technique was devised for use in cases of infertility when the
woman's fallopian tubes are damaged or the man's sperm count is low. It is
also used to enable prospective parents with other reproductive problems
(e.g., inability to produce eggs, poor sperm quality, or endometriosis )
to bear a child, and can be used in conjunction with embryo biopsy , or
pre implantation genetic diagnosis, to enable parents to have a child who
is free of some inheritable defects or diseases. In embryo donation (also
called embryo adoption), frozen embryos that are not needed by the mother
are donated for implantation to a woman or couple who are infertile but
wish to have, and are capable of bearing, children. The use of in vitro
fertilization has resulted in the birth of more than a million babies.
Nevertheless, the technique has raised legal, ethical, and religious
issues, including concerns regarding legal custody of frozen embryos
following divorce and questions regarding the appropriateness of the
procedure posed by the Roman Catholic Church and other institutions.
IVF Without Surgery - Transvaginal Oocyte
Retrieval
Due to improvements in ultrasound imaging, surgery is no longer necessary
for most In Vitro Fertilization patients. A technique for recovery of eggs
from the ovary is described below. It uses a sonographically-guided needle
to replace the surgical procedure which previously was used to recover
oocytes (eggs). This procedure, called Transvaginal Oocyte Retrieval,
requires neither hospitalization nor general anesthesia.
In order to prepare a proper environment in the woman and to increase the
chances of recovering several healthy and mature eggs, the woman will
undergo about two weeks of intensive preparation. This will include
hormonal therapy with "fertility drugs." Blood tests and ultrasound scans
of the ovaries are used to determine the optimal time to retrieve the eggs
from the ovary. This optimal time is just before ovulation when the
oocytes are almost ready for fertilization.
At the proper time, an outpatient procedure under local anesthesia will
allow the female's eggs to be visualized by ultrasound and retrieved from
the ovary by placing a needle through the vaginal wall. The mild
discomfort that the patient feels has been described as similar to a Pap
smear or endometrial biopsy. After a short rest, the patient will be able
to go home and resume normal activities.
The fluid from the follicles is examined under the microscope by the
embryologist, who locates the eggs and keeps them in the laboratory under
physiologic conditions. The embryologist will place the sperm with the
eggs when they are ready for fertilization. Usually, the eggs will develop
into cleaving pre-embryos, whose cells divide 2 or 3 times to become
preimplantation embryos (pre-embryos). They are maintained in laboratory
dishes, in a nutrient mixture which acts as a substitute for the
environment that would otherwise have been provided by the fallopian
tubes.
Using a special catheter, the couple's pre-embryos will be passed through
the vagina and into the uterus at the time the pre-embryos would normally
have reached the uterus (2+ days after retrieval).
After the pre-embryo placement in the uterus, the patient will lie quietly
in a bed for about an hour, and then will return home.
IVF-ET- Questions and Answers
Q: Will the In Vitro Fertilization technique
damage my ovaries ?
A: There is no evidence to suggest that either normal laparoscopy or
ultrasound egg retrieval damages the ovaries. In fact, some reports in the
medical literature suggest that following ovarian biopsy, pregnancies
occur in couples with a long-term history of infertility.
Q: Will scar tissue around my ovaries make it
impossible to retrieve the eggs ?
A: Not ordinarily. The surgeon must be able to see the follicles in order
to guide the needle to the proper spot for retrieval of the eggs whether
by sonographic (ultrasound) or surgical methods.
Q: What if I ovulate before oocyte (also
called egg or ovum) retrieval ?
A: Once ovulation has occurred it is impossible to retrieve the eggs. The
entire team of physician, nurse and embryologist will monitor your cycle
very carefully to avoid premature ovulation.
Q: If an egg is not retrieved or if the
technique does not produce a pregnancy on the first attempt, how soon can
the procedure be repeated ?
A: This depends on the individual. The primary reason for delay is to
allow the patient's normal menstrual cycle to resume, which may take 2 to
3 cycles.
Q: How many times will IVF be repeated per
couple ?
A: There is no specific number. This is determined by the couple together
with the physician.
Q: Can we have intercourse during the
two-week period before an IVF procedure is performed ?
A: Most definitely. We recommend that the husband refrain from ejaculation
for at least 48 hours, but for no more than 5 to 6 days preceding egg
retrieval. This precaution assures that the semen sample obtained for IVF
will contain a maximum number of healthy, motile sperm.
Q: After the IVF procedure, how long must we
wait to have intercourse ?
A: Although a definite time of abstinence to avoid damage to the
pre-embryo has not been determined, most experts recommend abstinence for
two to three weeks. Theoretically, the uterine contractions associated
with orgasm could interfere with the early stages of implantation.
However, intercourse the night before pre-embryo transfer is acceptable.
Some physicians will advise intercourse before transfer as they feel that
this will improve the chances of a pregnancy.
Q: What about other activities? How soon can
I resume my normal routine?
A: The IVF team recommends that the patient be sedentary for a full 24
hours following pre-embryo placement in the uterus. Strenuous exercises
such as jogging, horseback riding, swimming, etc. should be avoided until
pregnancy is confirmed. Otherwise, the patient is free to return to her
regular activities.
Q: How soon will I know if I'm pregnant ?
A: Pregnancy can be confirmed using blood tests about 13 days after egg
aspiration. Pregnancy can be confirmed by ultrasound 30 to 40 days after
aspiration.
Q: I had my tubes tied (tubal ligation)
several years ago. Would I be a candidate for IVF ?
A: Perhaps, in certain situations, IVF may be cheaper and physically less
demanding than surgery to repair you fallopian tubes.
Q: Is IVF covered by insurance companies ?
A: Unless your health insurance policy provides infertility coverage it is
unlikely that IVF coverage is provided. Frequently insurance policies will
cover infertility but exclude IVF. This has been successfully challenged
in the legal system. Consultation with your lawyer may be necessary to
review you insurance companies refusal to provide IVF coverage. If,
however, IVF is combined with surgical procedures used for diagnosis,
insurance carriers may pay for much of the procedure. However, coverage
will depend on the terms of your policy. For infertility alone, most
insurance policies will not provide coverage.
Q: What drugs are given to stimulate the
ovarian follicles and to maintain the lining of the uterus prior to
implantation of the pre-embryo ?
A: Four to five medications normally are given:
1. Leuprolide acetate (Lupron), an injectable drug that blocks secretions
of the pituitary gland, thereby optimizing the number of oocytes
retrieved;
2. Human menopausal gonadotropin (Pergonal or hMG) or Follicle Stimulating
Hormone (Metrodin or FSH), hormones that stimulate ovarian activity, are
injected daily for about 6-10 days prior to the procedure;
3. Human chorionic gonadotropin (hCG), a hormone that mimics the action of
the hormone which naturally induces ovulation, is injected 34 to 36 hours
before retrieval and may be used after retrieval to supplement natural
progesterone production;
4. Progesterone, a natural hormone that enables the uterus to support
pregnancy, may be used as a daily injection after egg retrieval; and
Q: What side effects, if any, can these drugs
cause ?
A: No pronounced side effects have been associated with any of these
drugs. However, the patient should inform the physician of ANY allergies
she has or of any previous adverse reactions to drugs.
Q: Will I have an egg in every follicle ?
A: It varies from patient to patient . As many as half of the follicles
may not contain an egg in some patients.
Q: Is there a possibility of multiple births
with IVF ?
A: Yes, when multiple pre-embryos are transferred. 25%. of pregnancies
with IVF are twins. (In normal population, the rate is one set of twins
per 80 births.) Triplets are seen in approximately 2-3% of pregnancies.
Q: Is there an increased chance of birth
defects if I become pregnant through IVF ?
A: There are no known ill effects. Abnormal pre-embryos, even those
produced through normal fertilization, do not seem to mature. However, any
long-term effects of IVF remain to be determined.
Q: How much time does the entire procedure
require ?
A: Approximately three weeks (all as an outpatient). Fertility drugs are
administered to stimulate the ovaries. Then during the four to six days
prior to ovulation, the patient is monitored by ultrasound as well as by
hormone levels.
Q: What happens to any extra pre-embryos ?
A: A maximum of four pre-embryos will be transferred to the uterus for
possible implantation. Patients will have several other options regarding
the disposition of the remaining pre-embryos. One option is to freeze
pre-embryos for your later use. Other options are to donate or simply
dispose of them. Excess pre-embryos, if any, belong to you, and you will
determine what is to be done.
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