Same sex couples are a step closer to having babies following a stem cell breakthrough by scientists at Cambridge University and the Weizmann Institute in Israel.
Researchers have shown it is possible to make human egg and sperm cells using the skin from two adults of the same sex – meaning lesbian and gay couples could have their own children.
The findings could also help men and women who are infertile, scientists noted.
Publishing their findings in the journal Cell, researchers used the skin from five adults to create stem cells that make sperm and eggs in the body. In total, they have created new cell lines from ten different donor sources - five embyros and five adults.
The team compared the engineered stem cells with natural human stem cells from aborted human foetuses to check they have identical characteristics, the Sunday Times reports.
They believe the technique could mean same sex couples could have babies in just two years.
Funded by the Wellcome Trust, the scientists had previously used the technique to create live baby mice from engineered eggs and sperm.
Findings showed the gene SOX17 – previously thought to be unimportant in mice – is critical in the reprogramming of stem cells in humans.
Azim Surani, leader of the project, said: "We have succeeded in the first and most important step of this process, which is to show we can make these very early human stem cells in a dish. We have also discovered that one of the things that happens in these germ cells is that epigenetic mutations, the cell mistakes that occur with age, are wiped out.
"That means the cell is regenerated and reset, so while the rest of the cells in the body have aged and contain genetic mistakes, these ones don't. We can't say no mutations are passed on, but mostly it doesn't happen."
Jacob Hanna, from the Weizmann Institute, added: "It has already caused interest from gay groups because of the possibility of making egg and sperm cells from parents of the same sex."
However, he said they are aware of the vast ethical concerns their findings raise in terms of the potential for designer babies: "I am not in favour of creating engineered humans and the social and ethical implications need to be thought through."