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How do gamete intrafallopian transfer and zygote intrafallopian transfer differ from standard IVF?
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infertility
Major structures and hormones involved in the initiation of pregnancy. Also seen, at right, is the development of an egg cell (ovum) from follicle to embryo.
Standard in vitro fertilization (IVF) involves removing eggs from the body, fertilizing them in a laboratory, and transferring the resulting embryos into the uterus for gestation. Gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) differ from this process primarily in where fertilization occurs and where the cells are placed.1
- GIFT: Unlike IVF, fertilization occurs naturally inside the body. Mature eggs and sperm are mixed together and placed directly into an unobstructed fallopian tube via laparoscopic surgery, which requires anesthesia.12
- ZIFT: Similar to IVF, eggs are fertilized in a laboratory. However, instead of being transferred to the uterus, the resulting zygote is placed into an unblocked fallopian tube before it begins to divide.31
While IVF transfers embryos to the uterus, both GIFT and ZIFT require at least one functional fallopian tube. A shared risk across these assisted reproductive technologies is the increased likelihood of multiple births, such as twins or triplets.1