Biology·Core Principles

Assisted Reproductive Technologies — Core Principles

NEET UG
Updated 22 Mar 2026

Core Principles

Assisted Reproductive Technologies (ART) are medical procedures designed to help infertile couples conceive. The most common ART is In Vitro Fertilization (IVF), where eggs are fertilized by sperm in a lab ('in vitro'), and the resulting embryos are transferred to the uterus.

Other key techniques include Zygote Intrafallopian Transfer (ZIFT), where fertilized eggs (zygotes) are placed in the fallopian tube, and Gamete Intrafallopian Transfer (GIFT), where unfertilized eggs and sperm are directly placed into the fallopian tube for natural fertilization.

Intracytoplasmic Sperm Injection (ICSI) is a specialized IVF technique where a single sperm is injected directly into an egg, primarily for severe male infertility. Artificial Insemination (AI), particularly Intrauterine Insemination (IUI), involves placing prepared sperm directly into the uterus.

These technologies offer solutions for various causes of infertility, including blocked fallopian tubes, low sperm count, and unexplained infertility, significantly expanding options for parenthood.

Often confused with

Side-by-side differences the NEET paper likes to test.

Assisted Reproductive Technologies vs IVF, ZIFT, and GIFT
AspectAssisted Reproductive TechnologiesIVF, ZIFT, and GIFT
Fertilization SiteIVF (In Vitro Fertilization)ZIFT (Zygote Intrafallopian Transfer)
Fertilization SiteOutside the body (in vitro)Outside the body (in vitro)
Transferred EntityEmbryo (cleavage stage or blastocyst)Zygote (fertilized egg, 1-cell stage)
Transfer SiteUterusFallopian tube
Fallopian Tube RequirementNot required (can be blocked/absent)Required (at least one healthy tube)
IndicationsBlocked tubes, severe male factor, endometriosis, unexplained infertilityFertilization issues, but healthy tubes

The core distinction among IVF, ZIFT, and GIFT lies in where fertilization takes place and what is transferred into which part of the female reproductive tract. IVF involves external fertilization and uterine transfer of an embryo.

ZIFT also uses external fertilization, but transfers the resulting zygote into the fallopian tube. GIFT is unique as it allows internal fertilization by transferring both eggs and sperm directly into the fallopian tube.

This means GIFT and ZIFT necessitate at least one functional fallopian tube, whereas IVF can bypass this requirement entirely.

Why it is tested: For NEET, understanding these distinctions is critical. Questions frequently test the site of fertilization and transfer, and the specific conditions under which each ART is indicated. Memorizing the acronyms and their procedural implications is a high-yield strategy.