Researchers have revealed they're getting closer to making it possible for same-sex couples to have a baby related to both partners.
Speaking at the Progress Educational Trust annual conference in London last month, Scientist Azim Surani revealed the results of his latest study.
The groundbreaking research, which is being reviewed for publication in a journal, followed Surani's team as they tried producing an artificial sperm and eggs.
According to Surani, the study went well and the team progressed further than anyone else in the process of making an artificial sperm and egg.
In previous studies, scientists used stem cells to create mouse sperm which was then used to produce healthy pups.
Speaking to The Guardian, Surani revealed his team was able to make it to the fourth week mark, the halfway point on the path of human stem cells turning into immature sperm/eggs. However, the team hope to eventually reach eight weeks.
The team developed miniature artificial testicles called gonadal organoids compromised of a blob of gonadal cells suspended in gel, also grown in the lab.
Despite achieving more than those before them, Surani claimed they still have a long way to go, and insisted in addition that the team have to be extremely careful in order to avoid any risks and genetic flaws which would potentially be passed on to future generations.
Surani said: "If this was ever going to be used in a clinical setting we have to be sure that it has gone through all the right stages - all of these steps are incredibly important.
"You can make an egg that looks like an egg, but it might not be the right cell in molecular detail. You could get a lot of problems with that. You don't want something that's going to grow into some kind of abnormal structure."
If the process is successful, it would allow infertile couples to produce a child related to the both of them. It would also allow a gay couple to have a baby that is genetically related to both of them by using skin cells from one to make an egg and skin cells from the other to make the sperm.
However, it's a long way off yet. The team claimed that such a possibility is at least ten years away.