Embryonic transfer is the moving of a fertilized egg that is between two and eight weeks old from the womb of one woman to the womb of another. The first successful human embryo transfer occurred in 1983. The transfer resulted in the birth of a live child.
English doctor Walter Heape performed a successful embryo transfer in 1890. He removed embryos from a female rabbit and placed them into a female hare (a hare is related to the rabbit), that subsequently gave birth. Further experiments were carried out on 15 different animal species. Embryo transfer became a valuable technique in the cattle industry. Superior animals could produce large numbers of embryos. These embryos could then be carried by less valuable cows. For example, a cow that was a good milk producer could produce the embryos that could them be implanted into cows that were poor producers. This way, more cattle with the desired traits could be raised by a number of different mothers.
Human Embryo Transfer
Human embryo transfer got its start in 1972. A Chilean team led by Horacio Croxatto developed a technique for flushing an unimplanted, unfertilized egg out of the uterus. The brothers Randolph Seed, a surgeon, and Richard Seed, the head of a cattle-breeding company, used a similar technique in 1980 to recover a fertilized egg. The brothers founded a company called Fertility and Genetics Research. This company funded a medical team at Harbor-UCLA Medical Center in Torrance, California.
The team began treating a group of infertile women, and advertised for egg donors. Healthy donors were matched with recipient couples for blood type, Rh, and hair and eye color. As each donor reached readiness for ovulation, she was inseminated with the husband's sperm. The fertilized egg was recovered and then transferred to the uterus of another woman. Two transfers performed by the team in 1983 resulted in the birth of babies early in 1984.
Embryo transfer is a valuable technique for overcoming infertility in women. It carries risks of infection for both donor and the recipient. It also carries the risk of unwanted pregnancy for the donor if the embryo implants in the uterine wall before it can be removed.
[See also In vitro fertilization ]