Gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) are both options for women and couples who need assistance conceiving. When deciding which procedure is best for you, it's important to understand the differences and similarities between the two treatments.
The Similarities in Treatment
As the similarity in the names of the procedures implies, gamete intrafallopian transfer and zygote intrafallopian transfer involve a number of similar steps. In both cases, you will begin medication four to six weeks before the procedure to encourage your ovaries to release multiple eggs in one cycle. About 36 hours prior to the treatment, your fertility specialist will then give you a shot of hormones that will better prepare your body for pregnancy. When it's time, your eggs will be extracted through the vagina via aspiration, a vacuum-like process.
Both processes will also involve a laparoscopic surgery in which the fertility specialist will implant a mixture directly into your fallopian tubes, where fertilization usually takes place in a natural cycle before the fertilized egg moves onto the uterus. This is different from in vitro fertilization (IVF), which requires that fertilized eggs are implanted into your uterus. Unlike IVF, both GIFT and ZIFT involve incisions in your abdomen, which increases the risk for infection and will leave a slight scar.
The Differences in Treatment
The key difference between gamete intrafallopian transfer and zygote intrafallopian transfer is what exactly is implanted into your fallopian tubes. During GIFT, your eggs are immediately mixed with the sperm after extraction and then promptly placed into your fallopian tubes as an unfertilized egg/sperm mixture. The intention is to let the eggs become fertilized within your body.
During ZIFT, as during IVF, your eggs will be fertilized with the sperm within the laboratory before the fertilized eggs are then implanted into your body. This process will likely involve some frozen or discarded fertilized eggs, as your fertility specialist will select the few that seem most likely to succeed for implantation.
Both GIFT and ZIFT have similar requirements for candidacy, as they both require that you have at least one healthy fallopian tube. They're usually options when a couple is experiencing problems with male infertility or when the infertility issue is unidentifiable, but IVF is an option as well. In approved candidates, GIFT has a success rate of around 25%, whereas ZIFT has a success rate of approximately 29%. It is notable, however, that ZIFT is much more likely to result in multiple pregnancies than GIFT, because multiple fertilized eggs are implanted into your body. About 35% of successful ZIFT pregnancies are multiples.
You may decide to choose gamete intrafallopian transfer over zygote intrafallopian transfer for ethical, cultural or religious reasons because it doesn't involve any human selection of "the best" fertilized eggs, nor does it involve any discarding or freezing excess eggs. GIFT is, however, slightly less likely to result in a successful pregnancy.
Both gamete intrafallopian transfer and zygote intrafallopian transfer may be able help you become pregnant. If you've been struggling for at least a year to become pregnant or are aware of infertility issues, discuss your candidacy for either of these options as well as other alternatives with your fertility specialist.