Year in review: ‘Three-parent baby’ technique raises hope and concern

Safety and ethical questions surround controversial mitochondrial replacement therapy

Embryo

SPINDLE SWAP  A boy born in April has DNA from mom and dad, as well as mitochondria from a female donor. To make "three-parent" embryos, the chromosome-containing spindle, shown at the tip of the pipette, is removed from a woman's egg and inserted into a donor egg.

Center for Embryonic Cell and Gene Therapy/Oregon Health & Science Univ.

A “three-parent baby” was born in April, the world’s first reported birth from a controversial technique designed to prevent mitochondrial diseases from passing from mother to child.