Infertility and Assisted Reproductive Technology (ART): Zygote Intrafallopian Transfer (ZIFT)
If your are experiencing difficulty getting pregnant, or if you or your partner are experiencing infertility, one infertility treatment that can be a good option is zygote intrafallopian transfer (or ZIFT). ZIFT is associated with a fairly high pregnancy success rate and is suitable for a variety of common male infertility and female infertility problems. But what exactly does ZIFT involve and what types of infertility problems do this assisted reproductive technology (ART) option work best for?
What is ZIFT?
During ZIFT, a woman’s eggs are fertilised with her partner’s sperm in the laboratory. Then, once the egg has been fertilised, it is transplanted into the fallopian tubes via laparoscopic surgery.
From here, the fertilized egg (or zygote) travels down the fallopian tubes and into the uterus, where, if the process is successful, it is implanted, resulting in pregnancy.
The Procedure: A Closer Look at ZIFT
A typical zygote intrafallopian transfer takes approximately four to six weeks to complete. However, in certain cases, more than one cycle of treatment is required.
First, a woman is given fertility drugs in order to stimulate the ovaries so that they may produce multiple eggs.
Once the eggs have matured, they are retrieved and are combined with sperm in the laboratory. Here, they are monitored for fertilisation.
After one day, the zygotes are ready to be retrieved. One to four zygotes are then transplanted into the fallopian tubes via diagnostic laparoscopy.
The zygotes are then monitored over the course of a few days in order to monitor for a pregnancy.
How Common is ZIFT?
ZIFT is not a very common procedure due to the fact that it is considered one of the most invasive forms of assisted reproductive technology.
It currently makes up only 1% of all assisted reproductive technology procedures in the United States.
However, ZIFT is increasing in its availability and last year over 280 babies were born in the United States via zygote intrafallopian transfer.
Who Can Benefit from Zygote Intrafallopian Transfer?
You may be a good candidate for ZIFT if:
- you have ovulatory problems
- your partner has a low sperm count
- your fallopian tubes are unblocked
- you have failed to get pregnant after one year of trying to conceive
- you have undergone five or more failed cycles of intrauterine insemination (IUI)
Who is Not Suitable for Zygote Intrafallopian Transfer?
ZIFT is not suitable in the following scenarios:
- you have blocked fallopian tubes
- you have severely damaged fallopian tubes
- you have uterine irregularities, such as a malformed uterus or uterine adhesions
Advantages of ZIFT
While ZIFT is fairly invasive, this assisted reproductive technology procedure enables your reproductive endocrinologist to ensure that your eggs are fertilised prior to implantation, unlike in GIFT, where combined sperm and egg are implanted into the fallopian tubes, and not a fertilised egg.
Also, some women prefer ZIFT because they feel it is a more natural process than other forms of ART, as the fertilised egg travels down the fallopian tube and into the uterus on its own.
Disadvantages of ZIFT
Alternatively, there are some disadvantages associated with ZIFT. As mentioned, it is a very invasive ART procedure, as it requires two surgical procedures (one when the eggs are retrieved and the other when they are implanted into the fallopian tubes).
In addition, ZIFT is associated with an increased risk of multiple pregnancies; ZIFT is associated with a 35% higher risk of multiple pregnancies. Multiple pregnancies in turn are associated with pregnancy complication such as early labour and low birth weight.
Also, ZIFT is an expensive alternative infertility treatment; one cycle can cost $15 000 to $20 000.
The ZIFT success rate depends on a woman’s age as well as what type of fertility problems her and/or her partner is experiencing. Generally, younger women have a greater chance of a successful pregnancy after undergoing ZIFT.
The average pregnancy success rate of ZIFT is 36% per cycle; 29% of these pregnancies are carried to term.
GIFT Versus ZIFT
If you are experiencing trouble getting pregnant, you may be considering both GIFT and ZIFT as alternative fertility treatment options. In general, it is recommended that you try GIFT first, as it is less expensive and carries a lower risk of multiple births and ectopic pregnancy.
If GIFT is unsuccessful, you may then want to consider ZIFT. However, ZIFT might be a better initial option depending on the cause of your infertility.