In vitro fertilization (IVF) has grown in demand since the first child was conceived by IVF in 1978. IVF is a multi-step process in which eggs (oocytes) are extracted from the woman’s ovary (where the eggs are produced), fertilized by sperm in a laboratory, cultured into early embryos and then transferred into the woman’s uterus. According to the Centers for Disease Control, in 2003 the live birth rate per cycle for IVF ranged from 37.3% for women under 35 years of age to 11% for women 41 to 42 years of age.
Gamete intrafallopian transfer (GIFT) was developed a few years after IVF. While it is sometimes used for young people who have unexplained infertility, it is less common than IVF. In 2003, 0.1% of cycles were GIFT cycle. In GIFT, eggs are retrieved from the woman’s ovary and placed with the male sperm (already obtained prior to the procedure) into a small catheter. The catheter (a flexible tube) is used to immediately deliver the eggs and sperm into the woman’s fallopian tubes where nature takes over. Unlike IVF, where fertilization occurs in the laboratory, in GIFT the fertilization takes place inside the woman’s body. The Centers for Disease Control lists the 2003 live birth rate per cycle for GIFT at 20.8%.
Zygote intrafallopian transfer (ZIFT) is essentially a blend of both GIFT and IVF: fertilization of the eggs occurs in the laboratory, but then the newly fertilized eggs are placed back into the fallopian tubes rather than into the uterus as they would in IVF. ZIFT procedures are appropriate in cases of decreased sperm counts, where there is question about the fertilization capacity of the sperm and where there may be anti-sperm antibody production. The popularity of ZIFT has also decreased recently, and in 2003 0.4% of ART procedures involved ZIFT.
