Some couples are childless because they are affected by conditions that prevent the sperm and egg from traveling through a fallopian tube. (Fertilization and the first stage of cell division occur inside fallopian tubes.) Gamete and Zygote Intrafallopian Transfer (GIFT and ZIFT) are assisted reproductive technology (ART) techniques that are hardly ever used but could improve the chances of conception in the fallopian tubes. The initial step of each of these treatments is superovulation. Hormone injections are used to stimulate the ovaries to produce multiple eggs.
Gamete intrafallopian transfer (GIFT) uses several eggs collected from the ovaries. The eggs are put into a thin flexible tube (catheter) along with the sperm to be used. The gametes (both eggs and sperm) are then inserted into the fallopian tubes using a surgical procedure known as laparoscopy. The doctor uses general anesthesia to perform laparoscopy.
Zygote intrafallopian transfer (ZIFT) uses both In-vitro fertilization (IVF) and GIFT. Eggs are stimulated and collected. Then the eggs are combined with sperm in the lab. Fertilized eggs (zygotes) are then laparoscopically transferred to the fallopian tubes from where they will move to the uterus. The aim is to implant zygote in the uterus and develops into a fetus.
Pronuclear stage tubal transfer (PROST), like ZIFT, uses IVF. But it transfers the fertilized egg to the fallopian tube before cell division occurs.
These methods are expensive and carry more risks related to laparoscopy. These methods do not provide as much helpful information about embryo development as IVF does. For these reasons, these ZIFT and GIFT procedures are rarely used.
Why It Is Done
GIFT may be suitable when:
Risks from laparoscopy (which is used to collect eggs) include pelvic infection, perforation of internal organs, and side effects from general anesthesia.
Assisted reproductive technologies—including GIFT and ZIFT—increase the chances of multiple births. Multiple pregnancies is high-risk for both the mother and the children.
For a woman around the age of 35, the best chance of conceiving with her eggs and having a healthy pregnancy, she ought to have more embryos transferred than a younger woman would. This increases the risk of multiple pregnancies.
Due to the risks to the babies of multiple pregnancies, experts suggest limiting the number of embryos transferred. Based on the age and situation, the doctor will advise a certain number of embryos to be transferred.
Women around 40 have a high rate of embryo loss when using their eggs. Instead, older women can opt to use more viable donor eggs.
What To Think About
ART birth rates can be deceptive. As a woman age crosses her mid-30s, her egg quality and quantity deteriorates. This makes it more and more unlikely that an ART procedure using her eggs will result in pregnancy and a healthy child. Many women over age 40 decide to use donor eggs. It greatly improves their chances of giving birth to a healthy child.
ZIFT involves two separate procedures. The first is to collect the eggs from the woman's ovaries. The second is done some days later when the fertilized egg (zygote) is transferred in her fallopian tube.
If GIFT fails, a doctor does not learn is unaware of 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.