IVF pioneer Lord Winston has warned that a growing market for fertility treatments could "threaten our humanity", including if the rich were able to pay for so-called 'designer babies'.
The fertility expert who developed key advancements in IVF treatment told fellow academics at a conference "we have been carried away" by breakthroughs in reproduction.
The Daily Mail reported him as saying that enthusiasm to develop fertility techniques and desperate patients has become a "toxic mix".
During his speech at the University of Kent said: "One of the problems with our work is that we have been carried away with massive enthusiasms in reproduction.
"That mixture of enthusiasm and patient desperation is actually a very toxic and heady mixture. It is worthwhile standing back a little from the technologies that we employ.
"One of the issues of the market is that rich people may well be able to afford, in due course, the kind of enhancement to their genetics that other poor people may not be able to afford."
The newspaper said he added that a growing market for fertility treatments and pressure to enhance human qualities could mean we "end up with a society where some people may actually have something that might threaten our humanity".
However, he said that the "the age of eugenics" could die out as issues such as the shortage of resources, water, food and the threat of climate change become more important.
Phillippa Taylor of the Christian Medical Fellowship welcomed Lord Winston's words.
He told the newspaper: "If Lord Winston is saying this, I hope that people take notice. He is someone who is an expert in the area but also someone who sees the bigger picture."
But Dr Allan Pacey, chairman of the British Fertility Society, said parents are not interested in enhancing their babies' genes.
"The law prohibits it, even if it was technically possible," he said.
"Most infertile couples are desperate for a baby, rather than a specific type of baby, and I don't see that changing."