What are GIFT and ZIFT?
GIFT (gamete intrafallopian transfer) and ZIFT (zygote intrafallopian transfer) are modified versions of in vitro fertilization. Like IVF, these procedures involve retrieving an egg from the woman and re-implanting it after manipulation. Unlike IVF, the timing between mixing the sperm and eggs and the transfer is faster.
In GIFT, the sperm and eggs are mixed together and immediately inserted. On the other hand, with ZIFT, the fertilized eggs --”zygotes”-- are inserted within 24 hours of the mixing.
What are the advantages to these procedures?
While the success rates are similar to IVF, the processes used in GIFT and ZIFT are closer to natural conception. In ZIFT, the eggs are placed in the fallopian tubes rather than directly in the uterus. With GIFT, fertilization actually takes place in the body rather than in a petri dish.
As in vitro fertilization techniques have become more refined, GIFT and ZIFT have become less relied upon. Additionally, as GIFT and ZIFT require surgery while IVF does not, IVF is the preferred choice in clinics. In vitro fertilization accounts for at least 98% of all assisted reproductive technology procedures performed in the U.S., while GIFT and ZIFT make up less than 2%.
What Types of Infertility Are Addressed By Gift and Zift?
GIFT and ZIFT can be used to treat many types of infertility, except cases caused by damage or abnormalities of the fallopian tubes. These techniques can also be used in cases of mild male infertility, as long as the sperm is capable of fertilizing an egg.
GIFT: What You Can Expect
Eggs and sperm are collected just as they would be in an IVF procedure, but after that, the two techniques differ. Unlike IVF, GIFT requires an incision be made in the abdomen and the eggs and sperm placed in the fallopian tubes using a laparoscope.
Because the eggs and sperm are placed into the fallopian tubes before conception, there's no way to know if fertilization has taken place prior to transfer. Typically, more eggs will be used in GIFT to ensure pregnancy, which has the side effect of increased multiple births.
ZIFT: What You can Expect
Unlike GIFT, with ZIFT the sperm and egg are mixed together in the laboratory, and given time to fertilize before being transferred to the fallopian tubes thus lowering the number of eggs used and correspondingly the chances for multiple pregnancy. As this is a post-fertilization technique, ZIFT is closer to in vitro fertilization. ZIFT, like GIFT, requires the procedure be performed by laparoscopy.