First Generation IVF “Free Love”:
Targeting: Female tubal factors, endometriosis, ovulation disorders.
Optimized handling of male and female gametes retrieved, allowing natural fertilization to occur outside the body. Embryos are cultured for 3-5 days before being transferred into the female uterus for conception.

Second Generation IVF “Arranged Marriage”:
Targeting: Severe male oligozoospermia or azoospermia, with sperm found through testicular biopsy.
Embryologists select high-quality sperm and use precise instruments to assist in injecting sperm into the cytoplasm of the egg, facilitating fertilization. Embryos are then implanted into the female uterus under appropriate conditions for conception.

Third Generation IVF “Competition for Marriage”:
Targeting: One or both partners with single-gene hereditary diseases, chromosomal disorders, or other genetic issues.
Several embryos are formed using second-generation IVF techniques and are cultured for 3 days or 5-7 days. Genetic screening is conducted on 1-3 cells from each embryo, and only genetically normal embryos are selected for implantation, assisting in female conception.

Fourth Generation IVF “Egg Donation”:
Targeting: Females with mitochondrial diseases or poor egg quality leading to fertilization failure or adverse pregnancy outcomes.
Currently facing ethical issues and not yet widely implemented. The nucleus of the female’s egg is extracted and transferred into the cytoplasm of an egg cell from a young, healthy donor, creating a new high-quality egg cell. Conception is then assisted through first or second-generation IVF techniques.