Any new baby is big news in a family, but the birth of one very special baby boy is making headlines worldwide. He's the first 'three-parent baby' to be created using a new technique.
The baby's mother carries a fatal genetic disease in her mitochondria - structures inside every cell that produce energy. Doctors took healthy donor mitochondria and combined them with the mother and father's DNA to produce a healthy embryo.
The donor 's mitochondria only accounts for 0.1% of the baby's genetic make-up. But this is controversial because of ethical questions it raises.