Wednesday 12 February 2014

What is gamete intrafallopian transfer (GIFT)?


Indications and Procedures

Couples who have sexual intercourse for a year without contraception and do not achieve pregnancy are defined as infertile. So too are couples who conceive but, because of repeated miscarriages, have not had a child. There are many possible causes of infertility. In women, they include abnormal or irregular ovulation, blocked or constricted fallopian tubes, and growths, scarring, or abnormalities of the uterus. In men, infertility may result from failure to ejaculate, low sperm count, abnormalities in sperm cells, or a blocked sperm tube. In many cases, no cause of infertility can be determined.


To have a child, some infertile couples turn to clinics offering assisted reproductive technology
(ART) services. The most common form of ART is in vitro fertilization
(IVF). Gamete intrafallopian transfer (GIFT) is similar to IVF, but it does not involve fertilization outside the body. Gametes (sperm and egg) are collected and then surgically introduced into a fallopian tube, where fertilization is expected to occur naturally.


Women who have at least one fallopian tube open are considered candidates for any of the ARTs, if sufficient numbers of healthy sperm can be collected from the male partner. GIFT may be the ART of choice for young women who have never undergone laparoscopy and for men with weak or few sperm. GIFT is sometimes employed in cases of unexplained infertility.


Prior to the procedure, egg maturation in the ovaries is stimulated with fertility drugs. With ultrasound guiding the probe, the physician retrieves eggs using a laparoscope. Sperm are collected several hours before the procedure. A laparoscope is also used to inject eggs and sperm into a fallopian tube. The patient may be awake or under general anesthesia for GIFT, which is typically done as a same-day, outpatient procedure. The American Society for Reproductive Medicine recommends that GIFT be performed only in a facility capable of performing IVF, in case GIFT fails or excess eggs are recovered.




Uses and Complications

All ART procedures involve risks, including general surgical risks and pregnancy complications such as multiple fetuses, low birth weight, and possibly certain birth defects. The rate of ectopic pregnancy (implantation outside the uterus) is also slightly higher. Multiple fetuses, which are present in nearly one-third of ART pregnancies, are associated with increased risk of prematurity, low birth weight, and neonatal death in the infant and of cesarean section and hemorrhage in the mother. Although ARTs are emotionally taxing, physically demanding, and expensive, thousands of infertile couples seek them annually.


The possible side effects of the hormonal drugs used to induce ovulation include hot flashes, changes in vision, ovarian cysts (sacs of fluid forming in the ovary), ovarian enlargement, and leakage of fluid into the abdominal cavity, which can trigger kidney failure, strokes, and heart attacks if not treated. IVF entails a slightly increased risk of chromosomal birth defects; whether GIFT carries a similar risk is unknown. ARTs do not appear to increase the overall risk of birth defects, although specific defects, such as vision problems, have been uncovered in some studies.


Some couples choose GIFT because they consider it more natural than IVF. However, GIFT is a riskier procedure than IVF, because laparoscopic surgery is required. Also, because fertilization is not confirmed before the injection of gametes, there is no way of knowing whether it occurred unless pregnancy is achieved. The mother’s age is an important factor: the younger the mother, the better the chance of success.




Perspective and Prospects

Before the 1970s, infertility treatment was limited mostly to the surgical repair of blocked Fallopian tubes and the insertion of sperm into the uterus (artificial insemination). In the early 1960s, Min Chang, a scientist at the Worcester Foundation in Shrewsbury, Massachusetts, performed the first IVF. He used sperm and eggs from black rabbits to grow embryos in vitro (meaning literally “in glass,” or in a laboratory dish). He then placed the embryos in the uterus of a white rabbit. A litter of black pups was born.


In 1969, English physician Robert G. Edwards successfully fertilized human eggs in vitro. Cell division was achieved a year later. He next collaborated with English physician Patrick Steptoe, who specialized in laparoscopic surgery. Together, they developed reliable techniques for retrieving eggs and maintaining embryos. The result was Louise Brown, the first “test tube baby.” She was born in England in 1978. In 1981, the breakthrough was replicated in the United States. During the following twenty years, more than one million IVF babies were born.


After that, the field of reproductive endocrinology flourished, as did the development of ART techniques. Ricardo H. Asch of the University of Texas at San Antonio performed the first successful GIFT in 1984. Another, similar development was zygote intrafallopian transfer (ZIFT), first successfully performed in 1986. ZIFT involves mixing sperm and eggs together outside the body and then confirming fertilization before the zygote is surgically placed in a fallopian tube. Another ART, intracytoplasmic sperm injection (ICSI), was introduced in 1992. It involves injecting a single sperm directly into an egg. It is often used in conjunction with IVF to fertilize eggs before embryo
transplantation.


Research and development activities continue to improve ART methods and techniques. Certain conditions within the fallopian tube that interfere with ART can now be treated, and better culture media have been developed for growing and maintaining embryos. The selection of smaller numbers of higher-quality embryos may cut the rate of multiple pregnancies, and improved methods for identifying those couples most likely to benefit from ART are being perfected. Researchers hope that implanting smaller numbers of more mature embryos will reduce the number of multiple births and diminish the risks that they entail.


ARTs raise ethical and social issues. Some churches and religious leaders oppose ARTs because they believe them to be unnatural or because some of the embryos produced in vitro are subsequently destroyed. Other controversies include pregnancies achieved in women past their natural reproductive age and legal issues surrounding the ownership of reproductive cells and frozen embryos.




Bibliography


A.D.A.M. Health Encyclopedia. "Infertility." MedlinePlus, February 26, 2012.



American Society for Reproductive Medicine. "Assisted Reproductive Technologies." American Society for Reproductive Medicine, 2013.



Johns Hopkins Medicine Fertility Center. "Gamete Intrafallopian Transfer (GIFT)." Johns Hopkins Medicine, 2013.



Meniru, Godwin I. Cambridge Guide to Infertility Management and Assisted Reproduction. New York: Cambridge University Press, 2001.



Peoples, Debby, and Harriette Rovner Ferguson. Experiencing Infertility: An Essential Resource. New York: W. W. Norton, 2000.



US Department of Health and Human Services. 2002 Assisted Reproductive Technology Success Rates: National Summary and Fertility Clinic Reports. Atlanta: Author, 2004.

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