‘Three parent babies’ aren’t new. Here is what science has accomplished so far

[E]ight babies have been born in the UK following an experimental form of IVF that involves DNA from three people.

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But these eight babies aren’t the first “three-parent” children out there.

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The first were reported back in the 1990s. Jacques Cohen … and his colleagues thought they might be able to treat some cases of infertility by injecting the mitochondria-containing cytoplasm of healthy eggs into eggs from the intended mother. 

Newer approaches to three-person IVF aim to include mtDNA from just the donor, completely bypassing the intended mother’s mtDNA. 

[John] Zhang took the nucleus of the woman’s egg and inserted it into a donor egg that had had its own nucleus removed—but still had its mitochondria-containing cytoplasm.

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Less than 1% of the boy’s mitochondria carried his mother’s mutation, so the procedure was deemed a success.

There was a fair bit of outrage from the scientific community, though. 

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The newly announced UK births are only the latest “three-person IVF” babies. And while their births are being heralded as a success story for mitochondrial donation, the story isn’t quite so simple.

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