Zygote intrafallopian transfer (ZIFT) is the newest variation of ART. This procedure requires that the woman have at least one functioning fallopian tube. Like IVF, the physician is able to confirm fertilization.
Follicle-stimulating hormones (FSH) are administered to stimulate the ovaries to produce several mature follicles so that multiple eggs can be harvested. These hormones are generally administered for a five to seven day period, during this time the woman is closely monitored to see if she is responding to the medication. A blood test is often used to check for an increase in estrogen levels which would signal developing follicles. An ultrasound may also be used to observe the growth and number of mature follicles.
Once the eggs have matured, then the retrieval process can begin. There are two methods used for egg retrieval. Using ultrasound, the physician uses the images on the video screen to locate the mature eggs for aspiration. The eggs can be retrieved by placing a needle through the top of the vagina occasionally, vaginal retrieval is not possible. Through the use of a laparoscope, a physician is able to view the pelvic structures as well as the ovaries and fallopian tubes through a tiny camera. The mature eggs are then harvested through the use of an aspiration system and the eggs are placed in a sterile test tube. A brief intravenous sedative is given so that the patient is comfortable. The procedure is usually less than 30 minutes.
Approximately two hours prior to egg retrieval, a semen sample is collected and through a process called sperm washing, the strongest sperm are selected. The sperm is later placed in a laboratory dish with the eggs. After 48 hours, if the eggs have been successfully fertilized and are growing normally, they are then ready for transfer to the uterus.
During this final ZIFT phase, the zygotes are placed in a catheter and transferred into the fallopian tubes.
Any zygotes that have not been utilized are placed in cryopreservation. Two weeks following the zygote transfer a pregnancy test will be performed.