What is GIFT?
The initials GIFT stand for gamete intra-fallopian transfer (gametes are reproductive cells — eggs and sperm). A by-product of IVF research, the procedure is suitable for women with normal fallopian tubes and is most commonly used to treat unexplained infertility.
IVF is often the first port of call. If the ability of the sperm to fertilise the egg is proven but pregnancy doesn't result, GIFT may be attempted.
The fact that fertilisation occurs in the woman's body overcomes some of the ethical dilemmas associated with IVF. However, the problem of obtaining sperm by masturbation remains a stumbling block for some people. With this in mind, silastic (chemical-free) condoms have been developed, so semen can be collected after intercourse.
Because conception takes place between consenting gametes in the privacy of your body, if pregnancy does not occur, there is no way of knowing whether it was because of lack of fertilisation or implantation. In some units, as many as 40 percent of cycles lead to conception.
How you qualify
GIFT is performed in IVF units and, as far as factors like age, health and other considerations are concerned, patients who would qualify for IVF can be accepted on a GIFT program. The most significant difference is that recipients of GIFT must have healthy fallopian tubes. It is sometimes used to overcome idiopathic (unexplained) infertility.
What happens?
In the initial stages, this follows many of the same steps as IVF. For example, the ovaries are stimulated (superovulated) and mature eggs are removed. But, instead of attempting fertilisation in a dish, egg and sperm are placed in a fallopian tube in the hope that they will mate "naturally". Because the transfer takes place within minutes of the egg extraction, it obviates the need for a second surgical procedure. This is how it works.
The eggs are examined under a microscope and the best are selected. (In most units, a maximum of two eggs are used at any one time to reduce the possibility of multiple pregnancy.) Meanwhile, scientists have been busy choosing top-grade sperm from your partner's ejaculation.
The eggs are drawn up into a catheter and a tiny air bubble is inserted to keep them apart from the sperm which will be added next. Sometimes, the sperm are divided into two portions, with the first half being placed in the catheter before the eggs, an air bubble added, followed by the eggs, another air bubble, then the rest of the sperm. The air bubbles are to ensure that an over-eager sperm doesn't penetrate one of the eggs before the gametes have been placed in a fallopian tube.
The catheter is introduced directly into a fallopian tube, either through the abdominal incision or transvaginally, depending on which extraction method has been used (see IVF), and the gametes are deposited there.
Beyond IVF and GIFT
ZIFT
A hybrid of IVF and GIFT, ZIFT (zygote intra-fallopian transfer) is also known as PROST (pronuclear stage transfer). A zygote is the cell formed by the union of a sperm and egg — the first, or pronuclear, stage in the life of an embryo.
As with GIFT, you need at least one good fallopian tube to qualify. Fertilisation is in vitro and the zygote is transferred to your tube as soon as laboratory staff confirm that the sperm has penetrated the egg. Because fertilisation occurs outside the body, this technique is not suitable for people with ethical/religious qualms about IVF.
TEST
Tubal embryo stage transfer is an extension of ZIFT. While zygote transfer is carried out as soon as fertilisation is confirmed, in TEST, embryos are not transferred for two or three days, until cell division has begun.
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