- GIFT: Gamete intrafallopian transfer
Gamete intrafallopian transfer (GIFT) is similar in many ways to IVF, with one very notable difference. As with IVF, a woman undergoing GIFT takes fertility drugs to stimulate multiple egg production in her ovaries, and the eggs are then removed from the woman’s body. Male sperm is collected and washed to separate the reproductive cells from other seminal fluids. The eggs are mixed together with a large number of sperm, but with GIFT, unlike IVF, no attempt is made at fertilization in the laboratory. The combined material is placed in a catheter and then, via laparoscopy, is injected into the woman’s fallopian tubes. There, hopefully, fertilization will happen. Some couples prefer this method to IVF for personal or religious reasons, as it allows conception to occur in its natural environment, rather than in a laboratory. A woman must have normal, functioning fallopian tubes to be a viable GIFT candidate. One potential drawback to GIFT is that there is no guarantee that fertilization will take place and, if it doesn’t, there is no way to determine the specific cause, which might complicate future treatment choices.
- ZIFT and TET: Zygote intrafallopian transfer and tubal embryo transfer
In zygote intrafallopian transfer (ZIFT) and tubal embryo transfer (TET), the beginning stages are similar to GIFT: a woman undergoes controlled ovarian hyperstimulation with the aid of fertility drugs in order to produce multiple eggs that are removed from her body, and male sperm is collected and washed and treated for optimal potency. However, in ZIFT and TET the laparoscopic transfer into the fallopian tubes occurs after fertilization has taken place in the laboratory. In ZIFT, eggs are retrieved and fertilized on one day, and the following day the embryo is transferred; TET gives the embryo a few more developmental days before it is moved to the fallopian tubes. Supporters of ZIFT and TET believe that by placing the embryo in the fallopian tubes (rather than the uterus, as in IVF) it will follow the body’s natural path to the uterus, making successful implantation and pregnancy somehow more likely. Here, too, it is essential for the woman to have functioning fallopian tubes.
- IUI: Intrauterine insemination
In intrauterine insemination (IUI), a form of artificial insemination, washed sperm is injected directly into a woman’s uterus (when she’s due to ovulate) via a catheter that is inserted all the way through the cervix. By placing the sperm inside the uterus (as opposed to the sperm having to make its way up the vaginal canal and through the cervix into the uterus), it is believed that it will be easier for the sperm to reach and fertilize a released egg. Also, if the woman is producing cervical mucous that is chemically inhospitable to her partner’s sperm, this potential problem can be avoided, since IUI bypasses the cervix. IUI is much less invasive than procedures like IVF, GIFT and ZIFT and can be particularly helpful in cases of male sexual dysfunction, some instances of sperm inferiority and where donor or cryogenically frozen sperm is being used. If the woman is ovulating normally, there is no need for her to take fertility drugs for IUI treatment, but IUI can also be used in combination with fertility drugs for a woman with ovulation issues.
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