Skip to Content

A Three-Parent Child Was Conceived in Mexico, Because the U.S. Won’t Allow It

Fertility doctors used a controversial technique to create a single egg from two women’s DNA, fertilized it, and watched as it grew into a healthy baby.
September 28, 2016

A baby boy with three biological parents was just born after being conceived in Mexico.

The infant came into the world thanks to a technique that involves manipulating the genetic material from two mothers before fertilizing the resulting egg with the father’s sperm. Variants of the process have been shunned by regulators in the U.S. despite the chance that they could help parents-to-be avoid passing down some rare genetic disorders.

The doctor who led the work, John Zhang of the New Hope Fertility Center in New York, used a process called spindle nuclear transfer to swap parts of the nuclei of five eggs from the boy’s mother into donor eggs before injecting sperm. Four of the five eggs began to grow, but only one developed normally.

The goal of the work is to allow mothers carrying genetic mutations that cause mitochondrial diseases, which afflict 1,000 to 4,000 people in the U.S. each year, to give birth to healthy babies. In the case of the couple that Zhang’s team worked with, the mother carries genes for Leigh syndrome, which is fatal. Before giving birth to her son in April, she had already had four miscarriages and two children who died of Leigh syndrome.

According to an interview in New Scientist, which first reported the story, Zhang said that U.S. regulations drove his team to move the procedure to Mexico—where, he said, “there are no rules.”

If such a statement sounds cavalier, outside scientists who commented on the work suggested that the team behaved ethically. The researchers made sure the baby was male to eliminate the possibility that mitochondrial DNA from the donor egg, which would be passed down through the maternal lineage, would not be inherited by any future generations.

This isn’t the first time a child has been born with three parents; the practice dates to the 1990s. In 2000 a girl was born whose parents used a different technique to conceive her, but it was shut down by the FDA the shortly thereafter. A similar process to the one Zhang used has been approved in the U.K.

For his part, Zhang has a history of working on the cutting edge of reproductive medicine. Over a decade ago, he implanted embryos with genetic material from three parents into a woman in China, and triplets began to grow. All three died before birth, but doctors at the time felt they might’ve made it if the woman had access to the better medical care available in the U.S.

(Read more: New Scientist, Wall Street Journal, “The Unintended Consequence of Congress’s Ban on Designer Babies”)

Keep Reading

Most Popular

Large language models can do jaw-dropping things. But nobody knows exactly why.

And that's a problem. Figuring it out is one of the biggest scientific puzzles of our time and a crucial step towards controlling more powerful future models.

OpenAI teases an amazing new generative video model called Sora

The firm is sharing Sora with a small group of safety testers but the rest of us will have to wait to learn more.

Google’s Gemini is now in everything. Here’s how you can try it out.

Gmail, Docs, and more will now come with Gemini baked in. But Europeans will have to wait before they can download the app.

This baby with a head camera helped teach an AI how kids learn language

A neural network trained on the experiences of a single young child managed to learn one of the core components of language: how to match words to the objects they represent.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.