Inside the race to make human sex cells in the lab

The way we make babies could be about to change. Maybe. 

An embryo forms when sperm meets egg. But what if we could start with other cells—if a blood sample or skin biopsy could be transformed into “artificial” sperm and eggs? What if those were all you needed to make a baby?

That’s the promise of a radical approach to reproduction. Scientists have already created artificial eggs and sperm from mouse cells and used them to create mouse pups. Artificial human sex cells are next.

The advances could herald the end of infertility—there’s no need to worry about a lack of healthy eggs or sperm if you can create new ones in the lab. It would open up alternative routes to parenthood as well. Same-sex couples could have genetically related children. If a cisgender woman could create her own sperm cells, she could use them to fertilize the egg of a partner. Likewise, a cisgender man could produce his own eggs to be fertilized by the sperm of his partner. And why stop there? The technology would allow four parents...