The idea of using a “three-parent baby” technique for infertility just got a boost

This week, I’ve been working on a big story about a controversial treatment that creates babies with three genetic parents. The “three-parent baby” technique was thought to help parents avoid passing diseases on to their kids. But new evidence suggests it doesn’t always work—and could create babies at risk of severe diseases.

The evidence comes from two babies born after the procedure was used to help couples with a different problem: infertility. It’s lucky we found the problem in these cases—these babies didn’t have parents with disease-causing mutations, so they should be fine.