- In This Feature
- The Acronyms
- Inducing Ovulation
- IVF (In Vitro Fertilization)
- The Fertility Guide: The ART Procedures
- Retrieving the Eggs
- GIFT (Gamete Intrafallopian Transfer)
- ZIFT (Zygote Intrafallopian Transfer)
- ICSI (Intracytoplasmic Sperm Injection)
- Cryopreservation of Eggs
- Decision-Making Guidance for Couples
- Summary and Perspective
GIFT (Gamete Intrafallopian Transfer)
Rather than a vaginal ultrasound approach for retrieval, a laparoscopy is required in order to do GIFT. The laparoscopy is necessary for visualization of the fallopian tubes so the eggs and sperm may be placed into them. Each follicle is again visualized, and the contents aspirated. After all of the follicles have been aspirated and the eggs isolated and evaluated, transfer of the gametes back into the fallopian tubes is performed. (The sperm sample from the husband is obtained prior to the procedure and has been fully prepared by this time.) Fifty thousand to one hundred thousand sperm, along with an appropriate number of eggs (see below) are then placed into a small catheter, which is directed into one or both fallopian tubes. The gametes are deposited in the fallopian tubes where fertilization normally occurs. Fertilization does not take place outside the body in a GIFT procedure; the sperm and eggs are placed in the fallopian tubes and nature takes over. This entire procedure takes less than 30 minutes and is done on an outpatient basis.
While GIFT is typically performed via laparoscopy under general anesthesia, there are other alternatives. Good success has been achieved doing a vaginal retrieval and then doing a laparoscopy using micro-instruments under local anesthesia and transferring the gametes to the fallopian tubes, thus eliminating the need for general anesthesia. Also, some physicians transfer the gametes to the fallopian tubes through the uterus rather than through the fimbriated end of the fallopian tube. (The feathery end, near the ovaries.)
GIFT differs from IVF in that we place the gametes directly into the fallopian tubes rather than bypassing them. The thinking here is that if the fallopian tubes are normal, and if we assume that the fallopian tubes can perform their normal functions better than we can mimic those functions in the lab, why not take advantage of this fact? Secondly, fertilization does not occur outside the body. In fact, the gametes are separated by a small air bubble and do not meet until they are placed into the fallopian tubes. This is very important to some individuals because of their religious beliefs. Finally, the gametes are in the laboratory for a very brief period and embryo culturing is not required. As will be discussed below, GIFT does have a better success rate than does IVF, at least on a national average basis, and some of these considerations may account for this.
In order to do GIFT, at least one of the fallopian tubes must be normal. Any woman with at least one normal tube and infertility related to just about any other problem is theoretically a candidate for a GIFT procedure, although couples who have anti-sperm antibodies and those with severely decreased sperm counts are best treated by other approaches. There is one other aspect of doing GIFT that must be borne in mind: If pregnancy does not occur, we have no information as to whether or not fertilization occurred. If there is significant question about the fertilizing capacity of the sperm, either doing cryopreservation in addition to GIFT or doing a different procedure should be considered.