Gamete and Zygote Intrafallopian Transfer (GIFT and ZIFT) for Infertility
Some infertile couples are affected by conditions that prevent the sperm and egg from traveling through a fallopian tube. (This is where fertilization and the first stage of cell division take place.) The following are assisted reproductive technology (ART) procedures that are rarely used but may improve the chances of conception in the fallopian tubes. The first step of each of these treatments is superovulation. This uses hormone injections to stimulate the ovaries to produce multiple eggs.
Gamete intrafallopian transfer (GIFT) uses multiple eggs collected from the ovaries. The eggs are placed into a thin flexible tube (catheter) along with the sperm to be used. The gametes (both eggs and sperm) are then injected into the fallopian tubes using a surgical procedure called laparoscopy. The doctor will use general anesthesia.
Zygote intrafallopian transfer (ZIFT) combines in vitro fertilization (IVF) and GIFT. Eggs are stimulated and collected using IVF methods. Then the eggs are mixed with sperm in the lab. Fertilized eggs (zygotes) are then laparoscopically returned to the fallopian tubes where they will be carried into the uterus. The goal is for the zygote to implant in the uterus and develop into a fetus.
Pronuclear stage tubal transfer (PROST), similar to ZIFT, uses in vitro fertilization. But it transfers the fertilized egg to the fallopian tube before cell division occurs.
These procedures have higher costs and risks related to laparoscopy. And they do not provide as much useful information about embryo development as IVF does. For these reasons, these procedures are rarely used.
What To Expect
Overall, having the assisted reproductive technology (ART)-related injections, monitoring, and procedures is emotionally and physically demanding. Superovulation with hormones requires regular blood tests and frequent monitoring by your doctor. It also requires daily shots. (Some of the shots are quite painful.)
You can expect to return to daily activities after a routine laparoscopic procedure in less than a week.
Why It Is Done
GIFT may be appropriate when:
- A couple has religious objections to fertilization taking place outside the body.
- A couple with unexplained infertility only has insurance benefits for GIFT.
For GIFT or ZIFT, a woman must have at least one functional fallopian tube.
How Well It Works
ZIFT and GIFT are used rarely enough that specific success rates aren't nationally available. But what is known about assisted reproductive technology (ART) includes the use of ZIFT and GIFT.
Risks from laparoscopy (which may be used to collect eggs) include pelvic infection, puncture of internal organs, and side effects from general anesthesia.
Assisted reproductive technologies—including GIFT and ZIFT—increase the risk of multiple births. A multiple pregnancy is high-risk for both the mother and the babies.
ZIFT success versus the risk of multiple pregnancy
For a woman over age 35 to have the best chance of conceiving with her own eggs and carrying a healthy pregnancy, she must have more embryos transferred than a younger woman would. This increases her risk of multiple pregnancy.
Because of the risks to the babies of multiple pregnancy, experts recommend limiting the number of embryos transferred. Based on your age and your situation, your doctor will recommend a certain number of embryos to be transferred.
Women over 40 have a high rate of embryo loss when using their own eggs. Instead, older women can choose to use more viable donor eggs.
What To Think About
ART birth rates can be misleading. As a woman ages past her mid-30s, her egg quality and quantity decline. This makes it increasingly unlikely that an ART procedure using her own eggs will result in pregnancy and a healthy baby. Many women over age 40 choose to use donor eggs. It greatly improves their chances of giving birth to a healthy child.
ZIFT requires two separate procedures. The first is to collect the eggs from the woman's ovaries. The second is done several days later when the fertilized egg (zygote) is placed in her fallopian tube.
If GIFT fails, a doctor does not learn anything about the sperm's ability to fertilize the eggs. With in vitro fertilization, the sperm fertilizes the egg in the laboratory. In that case, a health professional can tell whether fertilization has occurred and can follow embryo development.
ZIFT and GIFT may not be available in all areas. These procedures cost approximately $15,000 to $20,000 for each attempt. In vitro fertilization usually costs less.