context: GIFT (gamete intrafallopian transfer) and ZIFT (zygote intrafallopian transfer) are modified versions of in vitro fertilization ( IVF). Like IVF, these procedures involve retrieving an egg from the woman, combining with sperm in a lab then transferring back to her body, but in GIFT and ZIFT the process goes more quickly. While in traditional IVF the embryos are observed and raised in a laboratory for 3 to 5 days, in ZIFT, the fertilized eggs -- at this stage called zygotes -- are placed in the fallopian tubes within 24 hours. In GIFT, the sperm and eggs are just mixed together before being inserted and, with luck, one of the eggs will become fertilized inside the fallopian tubes. So what's the advantage of these procedures? For some women who haven't been able to get pregnant with normal in vitro fertilization, GIFT or ZIFT may be a good idea. 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. However, in vitro fertilization techniques have become more refined. And since GIFT and ZIFT both require a surgical procedure that IVF does not, IVF is almost always 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%. GIFT and ZIFT can be used to treat many types of infertility, except in cases where there is damage to 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. If the woman is not capable of producing eggs that can be used in GIFT, but her partner's sperm is capable of fertilization, they might consider getting eggs from a donor. One reason for using an egg donor is age. Women over age 35 are less likely to have viable eggs and more likely to have children with birth defects than younger women. A woman with premature ovarian failure, a condition in which menopause has begun early, might also consider a donor if she wants to carry a child. Most egg donation is anonymous, but some couples prefer to know their egg donor and take legal steps to contract for the donation of the eggs. The initial process for GIFT is the same as it would be for in vitro fertilization: treatment with injectable hormones to start superovulation, followed by further injections of a medication that ripens the developing eggs. The facility where the procedure will be done will provide you with special instructions to prepare you for the procedure. The eggs and sperm are collected just as they would be in an IVF procedure, but after that, the two techniques differ. In IVF, the embryo is placed into the uterus at 3-5 days with a catheter inserted into the vagina in a quick and simple procedure. In GIFT, an incision has to be made in the abdomen and the eggs and sperm are immediately placed in the fallopian tubes using a laparoscope, a small telescope-like instrument. A laparoscopy requires general anesthesia, although it can still usually be performed as an outpatient procedure. If all goes well, once the eggs are in the fallopian tubes, at least one will become fertilized by the sperm and move on to the uterus, where it will mature. But, because the eggs and sperm are placed into the fallopian tubes before conception, there's no way to know if fertilization has taken place. Typically, more eggs are used in GIFT to ensure pregnancy, which also increases the risk of multiple births. The American Society of Reproductive Medicine recommends that GIFT only be performed in a facility that is prepared to carry out IVF as an alternative or in addition to GIFT. This procedure is similar to GIFT in that the assisted reproduction is done in the fallopian tubes. The difference is that with ZIFT the sperm and egg are mixed together in the laboratory, and given time to fertilize before being placed in the fallopian tubes. In this sense, ZIFT is closer to traditional in vitro fertilization. ZIFT, like GIFT, requires treatment with hormones, and the procedure is performed by laparoscopy. Because ZIFT allows for fertilization to be confirmed before the eggs are inserted into the fallopian tubes, fewer eggs are usually used, lowering the risk of multiple pregnancy. The Centers for Disease Control groups together all procedures that constitute assisted reproduction technology ( ART), including in vitro fertilization, GIFT, and ZIFT. So there's no way to know the success rates of each technique. Combined, however, the most recent report based on data from 2015 and published in 2017 found: 29.3% of all cycles that used the woman's own eggs or embryos led to successful pregnancies. Single-fetus pregnancy accounted for about 70% of the pregnancies. Multiple-fetus pregnancy accounted for 23% of the pregnancies while the number of fetuses could not be determined in 7% of the pregnancies. About 70% of the cycles carried out did not result in a pregnancy. Less than 1% of all cycles resulted in an ectopic pregnancy (the embryo implants outside of the uterus). About 82% of pregnancies resulted in a live birth. About 18% of pregnancies resulted in miscarriage, induced abortion, or a stillbirth. Both procedures are expensive, typically costing between $15,000 and $20,000 a cycle. The cost will vary depending on where you live, the amount of medications you are required to take, the number of cycles you undergo, and the amount your insurance company will pay toward the procedure. GIFT and ZIFT may cost more than traditional in vitro fertilization. You should thoroughly investigate your insurance company's coverage of GIFT and ZIFT and ask for a written statement of your benefits. Although some states have enacted laws requiring insurance companies to cover at least some of the costs of infertility treatment, many states haven't. Also be aware that some carriers will pay for infertility drugs and monitoring but not for the cost of assisted reproductive technology. RESOLVE: The National Infertility Association, publishes a booklet called the " Infertility Insurance Advisor," which provides tips on reviewing your insurance benefits contract. RESOLVE's web site is www.resolve.org.