The history of single embryo transfer in human patients began with research conducted on mammals in the late 19th century. At that time, Dr. W. Heape experimented with embryo transfers in rabbits.
Early Embryonic Research
By the late 1930’s, the science was pushed forward by techniques that were described and appeared out of the imaginations of science fiction writers. Research continued over the next two decades, before Dr. M. Chang successfully used in vitro fertilization (IVF) techniques to impregnate a rabbit that carried the pregnancy full term (in 1959).
During the 1960’s, scientists continued to refine techniques that would make it possible to fertilize a human egg outside the womb. In 1973, a group of researchers announced they had successfully impregnated a woman using IVF techniques. Unfortunately, the pregnancy did not come to full term.
Development of Artificial Reproductive Technology
The 1980’s witnessed an explosion in assisted reproductive technology (ART) research and development. The first IVF birth in the U.S. occurred in 1981, followed by the first birth to a surrogate via embryonic transfer.
In 1986, the Monash research group announced they had retrieved sperm from a patient with a blocked duct. The sperm was used in an IVF procedure that resulted in pregnancy. By 1987, scientists reported they had been able to fertilize an ovum with one single sperm. This led to more developments in the field of sperm aspiration and extraction. It had been discovered that some males, who were considered infertile, were actually subfertile.
Focus on Male Reproduction
During the 1990’s, much of the ART research focused on male reproduction. By 1992, the first pregnancy resulting from intracytoplasmic sperm injection (ICSI) occurred. Shortly thereafter, testicular sperm extraction (TESE) methods were developed and introduced.
With TESE, it is possible to extract sperm from testes of males suffering from blockages or congenital defects; however, some males have very limited amounts of viable sperm. In 2004, Dr. Gardner and his associates developed the single blastocyst transfer (SBT) or single embryo transfer.
While research continues in the treatment of both males and females, the focus has shifted to the study of DNA and genetics.
