Moving one step closer to creating three-parent babies, scientists successfully fertilized a single egg made from those of two women. Though the Japanese team did not try to implant the embryo, there is hope the technique could one day be used to correct genetic problems or ease infertility: IVF is often unsuccessful for older women who have abnormalities in the area around the egg's nucleus; the researchers effectively sidestepped the issue by combining the nucleus of one woman's egg with the cytoplasm of a young donor, the Telegraph reports.
"If we could transfer these constructed new embryos, I believe the success rate would be high," the lead researcher said. Still, the technology is—and would be—controversial. Critics claim this type of treatment could lead to hybrid or genetically modified children.