I remembered that this happened years ago, with children of different races in the same womb

<link> From March 31, 1999

"A white woman who gave birth to two boys - one black, one white - due to a test-tube baby mix-up, has agreed to return the black child to his biological parents.

The fertility clinic in New York which accidentally implanted the woman with embryos belonging to another couple as well as with her own has been heavily criticised and now faces legal action."

Yes, largely unregulated industries are...problematic.

Oof. I was afraid of this. My search terms didn't turn it up. Fasano's name got me a bunch of other cases. Thanks for flagging it. I've revised the end and credited you.