Test
Tube Babies - IVF & GIFT
from
the book How to Have a Baby: Overcoming Infertility
by Dr. Aniruddha
Malpani, MD and Dr. Anjali Malpani, MD.
table
of contents·
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Donor
Sperms, Donor Eggs and Donor Embryos
Couples
with no sperm or eggs can undergo IVF and GIFT with the use of donor
sperm or eggs.
For IVF,
cryopreserved donor sperm are processed in the same way as fresh sperm.
In some cases of female infertility, fertilization may be attempted
first with the husband's sperm, and if this fails, donor sperm may
be used in a second attempt. Alternatively, if several eggs are aspirated,
some may be inseminated with the partner's sperm and some with donor
sperm.
Donor
eggs can be used in GIFT or IVF for women who have no eggs ( ovarian
failure) but who do have a healthy uterus. For GIFT, the woman must
also have at least one functional fallopian tube. In GIFT, the donor's
eggs are mixed with sperm from the husband. This mixture is injected
into the patient's fallopian tubes, while hormone supplements prepare
the uterus and aid in the initiation of pregnancy. For IVF, an embryo
resulting from the fertilization of a donor egg and the husband's
sperm is placed inside the patient's uterus.
A couple
may also choose to use donor eggs if the woman has a genetic disease
that could be passed on to a child. Donor eggs can also be used in
some cases of long standing infertility when other procedures have
failed - for example, women with many previous unsuccessful IVF cycles.
The use of egg donation is now becoming increasingly commoner , as
older women are seeking infertility treatment. Since the chance of
a pregnancy in the older woman depends directly upon the quality of
her eggs , many older women opt to use donor eggs from younger women
- which increases their pregnancy rates dramatically. This also creates
headline news, for example, when a menopausal woman has given birth
with donor eggs. In rare cases, when both the man and woman are infertile,
donor sperm and donor eggs have been used together.
Unfortunately,
it is still not possible to freeze and store eggs on a routine basis
- they are too fragile ! This is why fresh eggs need to be used for
donor egg treatments. These may come either from another infertile
patient; or a volunteer egg donor; or a friend or relative, who offers
to donate eggs.
Egg donation
for IVF or GIFT requires the egg donor to undergo ovulation induction
and ovum aspiration. The donation of eggs carries more risk and inconvenience
to the donor than does the donation of sperm.
The use
of donor eggs requires that the cycles of the donor and the recipient
be closely synchronized. This requires treatment of the recipient,
so that her endometrium is primed and is receptive to the embryos
at the time of transfer. For amenorrheic women with ovarian failure,
this can be achieved by treating them with exogenous estrogens and
progesterone. Other women who are cycling need to be downregulated
with GnRH analogs before starting treatment with exogenous estrogens.
In the
future, it is possible in the future that scientists will discover
ways to collect and store immature eggs. This may make " egg banks
" a reality , and considerably simplify the technique of egg donation
.
Couples
with both a sperm and an egg problem can also use donor embryos. Since
embryos can be stored, some infertile couples going through an IVF
cycle, who have chosen to freeze their supernumerary embryos for themselves,
are willing to donate their surplus frozen embryos to other infertile
couples when they get pregnant. Since donor eggs are still so hard
to come by, many couples may choose to resort to using donor embryos,
since these are much more easily available. You can think of donor
embryo treatment as very similar to adopting a baby - with the difference
that you are carrying the pregnancy and giving birth to the baby !
Some
couples are worried that if they use donor eggs or donor embryos,
their body will "reject " them, because these are genetically foreign.
However, remember that all embryos are genetically foreign to the
mother, because half the genetic material comes from the father !
The uterus is an "immunologically privileged" site, and donor embryos
have as good a chance of implanting as normal embryos.
Risks
and Complications of IVF and GIFT
[continued
on next page]
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