Test Tube Babies - IVF & GIFT (Page 7)
From the book
How to Have a Baby: Overcoming Infertility
by Dr. Aniruddha Malpani, MD and Dr. Anjali Malpani, MD.
What about using donor sperm, donor eggs and donor embryos in an IVF cycle ?
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.
Fig 1. Ultrasound scan of the egg donor after superovulation. She has grown many follicles and is ready for egg retrieval
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.
Fig 2. Mature oocyte cumulus complex
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.