U.S. health officials are weighing whether to approve trials of a pioneering in vitro fertilization technique using DNA from three people in an attempt to prevent illnesses like muscular dystrophy and respiratory problems. The proposed treatment would allow a woman to have a baby without passing on diseases of the mitochondria, the “powerhouses” that drive cells.

The procedure is “not without its risks, but it’s treating a disease,” says medical ethicist Art Caplan. Preventing a disease that can be passed down for generations would be ethical “as long as it proves to be safe. Where we get into the sticky part is, what if you get past transplanting batteries and start to say, ‘While we’re at it, why don’t we make you taller, stronger, faster or smarter?’ ”

“There is no genetic engineering. It isn’t a slippery slope. It’s a way to allow these families to have healthy children,” said Susan Solomon, director of the New York Stem Cell Foundation.

“What we’re doing is, without at all changing the DNA of the mother, just allowing it to grow in an environment that isn’t sick,” she added.

Mitochondrial disorders are inherited from the mother. In the procedure under discussion in Washington, genetic material from the nucleus of a mother’s egg or an embryo gets transferred to a donor egg or embryo that’s had its nuclear DNA removed.

The new embryo will contain nuclear DNA from the intended father and mother, as well as healthy mitochondrial DNA from the donor embryo — effectively creating a “three-parent” baby.

In June, Britain took a step toward becoming the first country to allow the technique. One in 6,500 babies in the United Kingdom is born with a mitochondrial disorder, which can lead to serious health issues such as heart and liver disease.

Caplan said the same technology could be used to modify an embryo to “making super babies,” a practice he said amounted to “eugenics.”

But Solomon said the procedure is closer to an expansion of in vitro fertilization, which has been available for nearly 40 years.