Difference Between ZIFT And GIFT

Overview of Assisted Reproductive Technologies (ART)

One of the commonly used Assisted Reproductive Technologies (ART) is In-vitro fertilisation (IVF). As its name suggests, it involves the fusion of male and female gametes outside the human body under strict laboratory conditions. The fusion results in a zygote and it is widely known as a test-tube baby. The embryo is then transferred to the uterus of the mother after culturing it. This procedure is performed when the fallopian tube of the mother is either non-functional or blocked.

What is ZIFT (Zygote Intrafallopian Transfer)?

Definition: Zygote Intrafallopian Transfer or ZIFT is an Assisted Reproductive Technology (ART) applied to treat infertility, when there are blockages in the fallopian tubes or unexplained reasons for infertility.

Process: In ZIFT, fertilisation occurs outside the body, in a petri dish, involving the sperm and eggs of the couple. After the zygote is produced, it is directly moved into the fallopian tube through a laparoscopic method.

Unlike IVF, where embryos are moved directly into the uterus, ZIFT allows the embryo to travel to the uterus using the natural passage, much like natural conception. As per the American Society for Reproductive Medicine, ZIFT has a success rate of approximately 22–26% per cycle, greater than that of GIFT because of proven fertilisation. Some basic steps are discussed below:

• IVF: Eggs are isolated from a woman's ovary and are fertilised with sperm in the laboratory.

• Zygote Formation: The fusion of sperm and ovum leads to the formation of a zygote.

• Transfer to the fallopian tube: The zygote is then transferred to the fallopian tube using a catheter.

• Success rate: Usually 30 to 40%. However, it may vary according to age and other factors.

• Ideal candidates: Women with either blockage or damage to the fallopian tubes.

What is GIFT (Gamete Intrafallopian Transfer)?

Definition: Gamete Intrafallopian Transfer (GIFT) is a form of ART where sperm and unfertilized eggs are inserted directly into a woman's fallopian tube.

Process: In ZIFT or IVF, fertilisation takes place naturally within the body, which is a closer approach to natural conception. GIFT is helpful in couples with unexplained infertility, irregularities in menstrual cycle, or minor male factor infertility. The treatment is performed through laparoscopy, typically after ovarian stimulation and egg retrieval.

Clinical statistics show that the pregnancy rate per cycle is around 21–23%. A little less than ZIFT because of the unreliability of in vivo fertilisation. Although its application has reduced with the advent of IVF. The procedure involves transferring ova and sperm into the fallopian tubes so fertilisation can take place naturally. Some of the major steps involved in the process are discussed below:

• Collection of egg and sperm: Ova are collected from the ovaries, and sperm is collected from the male.

• Direct transfer: Both the ova and the sperm are directly transferred into the fallopian tubes using a catheter.

• Pregnancy rates: About 20-30%, depending on the female's age and cause of infertility.

• Ideal candidates: Women having at least one normally functioning fallopian tube. Women with no severe infertility problems.

ZIFT vs GIFT - Difference Between ZIFT And GIFT

ZIFT and GIFT are two reproductive technologies (ARTs) to treat infertile couples. Although both involve the transfer of reproductive cells into the fallopian tubes, the only difference is in the developmental stage at which the cells are being transferred. The table below discusses the important points on which ZIFT and GIFT differ from each other.

Table: Difference Between ZIFT And GIFT

Clinical Applications and Success Rates

GIFT is used for infertility with at least one functional fallopian tube. It allows natural fertilization in vivo. On the other hand, ZIFT is used when the fallopian tubes are blocked or in the cases of failed IUI cycles. ZIFT requires fertilisation to occur in vitro before transferring the zygote into the fallopian tube for implantation.

The success rate depends on various factors like age of the female, quality of egg and sperm and functioning of fallopian tubes. The success rate decreases as the age of the female increases and the quality of the gametes is low. ZIFT has a higher success rate than GIFT. In women under 35 years, the success rate in ZIFT is 30-40% whereas in GIFT it is 25-35%. This rate gradually decreases with the increasing age of the women.

Risks and Limitations

Risks

Multiple Births: GIFT and ZIFT increases the chance of carrying multiple babies which is high risk for both mother and babies.

Ectopic Pregnancy: It is a condition in which the zygote is implanted outside the uterus generally in the fallopian tube. It possesses a potential threat to the mother.

Ovarian Hyperstimulation Syndrome (OHSS): Drugs are given to stimulate the production of the egg. This can cause the ovaries to become painful and sometimes leads to OHSS.

Limitations

Expensive: Both of the procedures require fertility drugs and a surgical step making it more costly and risky than other methods.

Healthy Fallopian Tubes Required: It is not suitable for women who have blacked or damaged fallopian tubes.

Outdated and Low Efficiency: It has lower success rates compared to the newer techniques like IVF or ICSI, which are now more widely used with higher success rates and no need for tubal transfer.

ZIFT & GIFT NEET MCQs

Q1. What are the differences one can spot between ZIFT and GIFT?

1. GIFT involves the transfer of fertilized eggs, while ZIFT involves the transfer of gametes.

2. GIFT is a procedure of fertilization outside the body, while ZIFT is a procedure of fertilization inside the body.

3. GIFT can be used in cases where the woman has a damaged fallopian tube, while ZIFT cannot.

4. GIFT and ZIFT have the same success rates in terms of pregnancy rates.

Correct answer: 2) GIFT is a procedure of fertilization outside the body, while ZIFT is a procedure of fertilization inside the body

Explanation:

The major difference between GIFT and ZIFT is that GIFT is a procedure of fertilization outside the body, while ZIFT is a procedure of fertilization inside the body. In GIFT, the sperm and eggs are transferred into the fallopian tube, where fertilization occurs naturally, while in ZIFT, the fertilized eggs are transferred into the fallopian tube. GIFT requires a functioning fallopian tube, while ZIFT can be used in cases where the woman has a damaged fallopian tube. Both procedures have similar success rates in terms of pregnancy rates.

Hence, the correct answer is option 2) GIFT is a procedure of fertilization outside the body, while ZIFT is a procedure of fertilization inside the body.

Q2. Which technique from the options utilizes an in-vivo approach for the desired outcome?

1. ZIFT

2. GIFT

3. ICSI

4. IUT

Correct answer: 2) GIFT

Explanation:

GIFT (Gamete Intrafallopian Transfer) is a technique that utilizes an in-vivo approach. In GIFT, both the sperm and egg are collected and transferred directly into the fallopian tubes. This allows fertilization to occur naturally within the woman's body. It is an in-vivo procedure because the fertilization takes place inside the fallopian tubes, within the woman's reproductive system.

Hence, the correct answer is option 2) GIFT.

Q3. Choose the correct statement regarding the ZIFT procedure:

1. Ova collected from a female donor is transferred to the fallopian tube to facilitate zygote formation.

2. A zygote is collected from a female donor and transferred to the fallopian tube.

3. A zygote is collected from a female donor and transferred to the uterus.

4. Ova is collected from a female donor and transferred to the uterus.

Correct answer: 2) A zygote is collected from a female donor and transferred to the fallopian tube

Explanation:

ZIFT is an advanced ART method aiming to achieve pregnancy. Here's a concise breakdown of the process:

1. Egg retrieval: Mature eggs are obtained from the female's ovaries through medical procedures.
2. Fertilization: Eggs are united with sperm in a lab to create a zygote.
3. Zygote transfer: The zygote is inserted into the fallopian tube within 24 hours post-fertilization using a special tool.
4. Natural progression: The zygote moves to the uterus, potentially leading to successful implantation and fetal development.

Key aspects:
- ZIFT merges IVF and natural implantation.
- Zygote transfer occurs earlier compared to IVF's embryo transfer to the uterus.

When is ZIFT employed?
- Infertility with at least one functioning fallopian tube.
- Unexplained infertility after IUI treatments fail.

Limitations to note:
- Requires operational fallopian tubes for zygote transport to the uterus.
- More invasive than standard IVF due to surgical transfer.

Hence, the correct answer is option 2) A zygote is collected from a female donor and transferred to the fallopian tube.

Also Read:

• MCQs on GIFT and ZIFT

• Contraception

• Sexually Transmitted Diseases

FAQs on ZIFT and GIFT

What is ZIFT in biology?

ZIFT (Zygote Intrafallopian Transfer) is an assisted reproductive technology (ART) used to treat infertility, especially when fallopian tubes are blocked or damaged. In this process, eggs are collected from the woman’s ovary and fertilised with sperm in a laboratory (IVF). The resulting zygote is then transferred into the woman’s fallopian tube through laparoscopy. This allows the zygote to travel naturally to the uterus for implantation, similar to natural conception.

What is GIFT in biology?

GIFT (Gamete Intrafallopian Transfer) is an ART method where unfertilised eggs and sperm are directly placed into the woman’s fallopian tube through laparoscopy. Fertilisation occurs naturally inside the body. It is useful for couples with unexplained infertility or minor male infertility. This technique requires women with at least one healthy fallopian tube.

What is the difference between ZIFT and GIFT?

The main difference is in the stage of transfer. In ZIFT, a fertilised zygote is transferred into the fallopian tube, while in GIFT, unfertilised eggs and sperm are transferred together for in vivo fertilisation. ZIFT ensures proven fertilisation before transfer, whereas GIFT relies on natural fertilisation inside the body. ZIFT is used when fallopian tubes are blocked whereas GIFT is used when, at least one fallopian tube is without any blockage

Which technique has a higher success rate, ZIFT vs GIFT?

ZIFT generally has a higher success rate, about 30–40%, because fertilisation is confirmed before transfer. GIFT has a slightly lower success rate of around 20–30%, as it depends on successful natural fertilisation inside the fallopian tube. Success rates may vary based on the woman’s age, health, and cause of infertility.

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