Exploring Zygote Intrafallopian Transfer (ZIFT) for Fertility Hope

Introduction

Raising children is more important than giving birth to a child. Being a parent to a child gives fulfilment to their life in some people’s life. Some people decide not to have children after thinking about it carefully on a personal level. 

Some regret not having children because society’s expectations and standards might raise this concern. The general and frequent outcomes of not having children are distress, increased anxiety levels, increased depression, lowered self-esteem, feelings of guilt, feelings of blame and other somatic complaints. 

As per a study, the percentage of childless households in the US is nearly going to reach 50% in the coming years. In India, the percentage of childless married women has increased to 12% in 2019-2021. 

For couples who long for children, there is a treatment called ZIFT, which is similar to the IVF method. ZIFT was reported for the first time in 1988, although the practice was first mentioned in 1986. The transfers of cryopreserved embryos received from donor eggs, host cycles, and combination cycles were reported for the first time in 1991. 

What is ZIFT?

Zygote intrafallopian transfer (ZIFT) is an assisted reproductive technique that shares similarities with in vitro fertilization and embryo transfer. This procedure is also known as tubal embryo transfer (TET) due to the direct transfer of the fertilized egg into the tubes.

However, what sets it apart from in vitro fertilization and embryo transfer is that the fertilized embryo is specifically placed inside the fallopian tube rather than the uterus. 

Compared to gamete intrafallopian transfer (GIFT), ZIFT has a higher success rate since the physician can ensure the fertilization of the egg more effectively.

One advantage of ZIFT is the clear confirmation of fertilization. For ZIFT to be successful, it is crucial for the woman to have healthy fallopian tubes.

In contrast, with GIFT, it is not immediately determinable if the egg and sperm have combined to form a zygote, which is an early-stage embryo.

Who is eligible to undertake ZIFT treatment? 

ZIFT is usually selected by couples who have not succeeded even five to six cycles of ovarian stimulation with intrauterine insemination (IUI). Also, some couples choose this treatment method who have not succeeded in getting a child after they tried for a minimum of one year to conceive. 

ZIFT is an assisted reproductive procedure treatment for many infertility issues except for couples with the following issues:

• Specific tubal damage
• Tubal blockage
• Sperm unable to get into an egg
• Specific anatomic issue with the uterus

Requirements for ZIFT

To carry out the ZIFT procedure successfully, the patient needs to have unobstructed and undamaged fallopian tubes. This requirement is because the embryo must pass through the introduced tubes to reach the uterus and implant itself. So, at least one of the fallopian tubes must be open and functioning properly for ZIFT to be a viable option. 

Conversely, it is not recommended to perform ZIFT on individuals with uterine complications or a past history of ectopic pregnancies.

What are the phases in ZIFT?

To finish one treatment for ZIFT requires four to six weeks. Some of ZIFT’s initial steps are very similar to those of IVF. 

1. Ovary Provoke

The patient (or female partner in the selected couple) will be provided with medication to take to stimulate their ovaries to grow mature eggs. This step prevents their body from releasing the eggs too early.

2. Follicle development

The patient must visit their doctor every two to three days while taking fertility medication. This is because the doctor might check your blood hormone levels and note the ultrasound measurements of your developing follicles.

3. Collection of the eggs

When the eggs are ready for revival, then your doctor will look at the ovaries of the patient, using an ultrasound probe after providing them with an anaesthetic. In this step, around eight to fifteen eggs are removed from the patient after inserting a thin needle into the vaginal wall. 

4. Fertilization

The eggs collected from the female will be fertilized with her partner’s or donor’s sperm in a well-maintained lab. After that, they will be monitored closely, and a day later, each of the successfully fertilized eggs will turn into a single-celled embryo called a zygote.

5. Surgery

Once a zygote is formed, the doctor will give the patient an anaesthetic and perform a laparoscopy. Nearly five zygotes will be transferred to the fallopian tubes with the help of a thin tube called the laparoscope. The patient must take a complete rest for some time following this procedure.

6. Implantation and Baby Growth

Once the implantation is successful, the zygote goes through the fallopian tube and implants in the uterus of the female patient. Then, a baby will begin to grow in the uterus. When more than one of the zygotes is transferred, the chance of pregnancy is higher. But, the patient might face the risk of having a multiple pregnancy.

What are the steps in the ZIFT?

Zygote intrafallopian transfer(ZIFT) is somewhat similar to IVF but has small differences. Zygote intrafallopian transfer(ZIFT) involves the following steps:

• The woman’s ovaries are stimulated using medications to enhance the chances of producing multiple eggs.
• Eggs are gathered using a longing method. 
• These eggs are then fertilized in a laboratory. This step is very similar to the in vitro fertilization (IVF) process, with the only difference being the timing. In the ZIFT procedure, the fertilized eggs are transferred within 24 hours, whereas a regular IVF cycle typically involves a timeframe of 3-5 days.
• The fertilized eggs are transferred using a laparoscopic procedure.
• In the laparoscopic procedure, a catheter is carefully inserted deep into the fallopian tube, and then the fertilized eggs are injected.
• At last, they will monitor for the early signs of pregnancy. The fertility specialist may conduct a blood test to check if pregnancy has occurred.

What are the major differences between ZIFT and GIFT?

• ZIFT is zygote intrafallopian transfer, while GIFT is Gamete Intrafallopian Transfer. ZIFT and GIFT are alternative approaches to in vitro fertilization (IVF) but with some modifications. 
• In ZIFT, the fertilized eggs, known as zygotes, are inserted within 24 hours of mixing. Conversely, in GIFT, the sperm and eggs are mixed and promptly inserted. 
• In ZIFT, the eggs are placed directly into the fallopian tubes instead of the uterus. With GIFT, fertilization occurs inside the body rather than in a laboratory dish.
• Similar to IVF, these procedures involve the retrieval of an egg from the woman and subsequent re-implantation after manipulation. However, there are differences in the timing between sperm egg mixing and the transfer.
• Although the success rates are comparable to IVF, ZIFT and GIFT methods closely resemble natural conception.

Advantages of ZIFT

Zygote intrafallopian transfer (ZIFT) offers several advantages compared to conventional in vitro fertilization (IVF). 

• ZIFT also holds an advantage over gamete intrafallopian transfer (GIFT). In GIFT, the eggs and sperm are inserted into the patient’s fallopian tube to facilitate fertilization within the tube. Consequently, it is not possible to confirm whether fertilization has occurred correctly. In contrast, ZIFT allows laboratory verification that fertilization has occurred accurately.
• Moreover, one key advantage is that ZIFT closely mimics natural physiological processes. By reducing the time the embryo spends in the laboratory, ZIFT enables the embryo to develop inside the woman’s body.
• ZIFT avoids the need for intrauterine manipulation, making it an alternative option for patients who have experienced repeated implantation failures in IVF cycles and traditional embryo transfers. However, there are conflicting results regarding whether these patients truly benefit from ZIFT.
• ZIFT optimizes the synchronization between the embryo and the development of the endometrium (the uterus lining). 

Disadvantages of ZIFT

ZIFT also has several drawbacks when compared to other methods. 

• Firstly, the procedure involves surgery, increasing difficulty, risk, and cost. 
• In contrast, uterine transfer is a painless procedure that only requires the introduction of embryos through the cervix using a fine cannula.
• It’s worth noting that since multiple zygotes are typically introduced, the rate of multiple pregnancies may be higher than other techniques.
• Another disadvantage of ZIFT is the higher likelihood of ectopic pregnancies. This is because the embryos are not directly transferred into the uterus, increasing the chances of implanting outside the uterus.
• Due to these reasons, IVF, followed by transcervical embryo transfer, has gained preference over ZIFT.

Cost of Intratubal Zygote Transfer

Several factors decide the cost of the Intratubal Zygote Transfer. According to the fertility clinic, the cost of assisted reproductive techniques varies, so the price of ZIFT might vary.

However, ZIFT is not available in all clinics, as it is a more invasive method that needs surgery. So, the cost of ZIFT in clinics is higher compared to an IVF cycle with conventional intrauterine transfer.

Why the ZIFT is not in use?

The larger pregnancy rate is achieved with the help of the intrauterine embryo transfer, so the Transtubal transfer is no longer used. 

In the past, when the ZIFT technique was performed, its results were not as good as in utero transfer. Also, it is an invasive method, as it needs sedation of the patient and is performed laparoscopically.

Conclusion

Zygote Intra-Fallopian Transfer (ZIFT) shares similarities with Gamete Intra-Fallopian Transfer (GIFT) in that it requires hormonal treatment and is conducted through laparoscopy. 

ZIFT, also called Tubal Embryo Transfer, is an assisted reproductive technology (ART) procedure analogous to in vitro fertilization (IVF). In ZIFT, the fertilization process occurs in a laboratory setting. The resulting zygote is then transferred to the mother’s fallopian tube using laparoscopy. The sequence of steps in ZIFT involves retrieving eggs from the ovaries, fertilizing them and transporting the zygote to the fallopian tubes for implantation and further development. It is important to note that ZIFT is not suitable for women with abnormal uterine tubes. 

However, ZIFT offers the advantage of confirming fertilization before the eggs are inserted into the fallopian tubes, resulting in fewer eggs and reducing the risk of multiple pregnancies. Unlike GIFT, ZIFT patients know that sperm and eggs have been fertilized.

Both GIFT and ZIFT, as forms of assisted reproductive technologies, carry an increased risk of multiple births. However, there are certain drawbacks associated with ZIFT, such as the complexity of the procedure, higher risk of ectopic pregnancies, increased cost, and the requirement for two separate operations within a short timeframe.

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