Key Points: Assisted Reproductive Technologies
Five ART Techniques — Master Comparison
| Technique | Fertilization Site | Transfer Site | Best Indication |
|---|---|---|---|
| IVF-ET | In vitro (lab) | Uterus | Blocked fallopian tubes |
| ZIFT | In vitro (lab) | Fallopian tube (up to 8-cell) | Intact tubes, early transfer |
| GIFT | In vivo (fallopian tube) | Fallopian tube (gametes) | Natural fertilization preferred |
| ICSI | In vitro (oocyte cytoplasm) | Uterus (post-injection embryo) | Severe male infertility |
| AI/IUI | In vivo (fallopian tube) | Uterus/cervix | Mild male infertility |
Critical Distinctions
- ZIFT vs IVF-ET: Both involve in vitro fertilization. ZIFT → fallopian tube; IVF-ET → uterus.
- GIFT vs ZIFT: Both transfer to fallopian tube. GIFT → unfertilized gametes (in vivo fertilization). ZIFT → fertilized zygote.
- GIFT = only ART with in vivo fertilization (all others have in vitro fertilization).
- ICSI = only 1 sperm needed; bypasses zona pellucida; for severe male infertility.
- AI/IUI = least invasive; processed semen; no external fertilization.
Key Factual Points
- IVF-ET = "test tube baby" — fertilization only is in vitro; development in uterus
- ZIFT maximum stage: 8-cell embryo (zygote to 8-cell)
- IVF-ET transfer stage: 8-cell or blastocyst
- ICSI injects sperm into oocyte CYTOPLASM (not nucleus)
- GIFT: donor oocyte possible; fertilization inside fallopian tube (in vivo)
Memory Device "Z and G go to the Fallopian tube (Z=fertilized, G=unfertilized). IVF baby goes to the Uterus."