As early as the 1950s, Dr. Edwards had the idea that fertilization outside the body could represent a possible treatment for infertility. Other scientists had shown that egg cells from rabbits could be fertilized with sperm in test tubes, producing offspring. Dr. Edwards decided to investigate whether similar methods could be used to fertilize human egg cells.
In a series of studies conducted with co-workers, Dr. Edwards made a number of fundamental discoveries.
He clarified how human eggs mature, how hormones regulate their maturation and at which point the eggs can be fertilized. He also determined the conditions under which sperm is activated and can fertilize the egg.
By analyzing the conditions necessary for an egg and sperm to survive outside the womb, Dr. Edwards developed a medium — which he called “a magic culture fluid” — in which to achieve fertilization.
In 1969, his efforts met with success when, for the first time, a human egg was fertilized in a test tube. But the fertilized egg did not develop beyond a single cell division. Dr. Edwards suspected that eggs that had matured in the ovaries before they were removed for in vitro fertilization would function better. He looked for possible ways to safely obtain such eggs.
Dr. Edwards contacted Patrick Steptoe, a British gynecologist at the Oldham and District General Hospital near Manchester, England. Steptoe was one of the pioneers in laparoscopy, which allows examination of the ovaries through an optical instrument.
Steptoe used the laparoscope to remove eggs from the ovaries, and Dr. Edwards put the eggs in cell culture and added sperm. The fertilized egg cells divided several times and formed early embryos composed of eight cells, known as a blastocyst.
“I’ll never forget the day I looked down the microscope and saw something funny in the cultures. . . . What I saw was a human blastocyst gazing up at me,” Dr. Edwards recalled in 2008. “I thought, ‘We’ve done it.’ ”
The research became the topic of intense ethical debate. Religious leaders, ethicists and scientists demanded that the project be stopped.
Steptoe “faced immense clinical criticism over his laparoscopy, even being isolated at clinical meetings in London,” Dr. Edwards wrote in the biomedical research journal Nature Medicine in 2001 after receiving the prestigious Albert Lasker Award for Clinical Medical Research. “Ethicists decried us, forecasting abnormal babies, misleading the infertile and misrepresenting our work as really acquiring human embryos for research.”