Scientists will be ready to create babies from three people in around two years, if it is made legal, a review says.
The technique, using eggs from two women and one man's sperm, would be used to prevent deadly mitochondrial diseases.
The UK fertility regulator said there was no evidence that it would be unsafe, but called for extra checks.
Changes to fertility regulations are being considered by government.
The illness is caused by damage to the tiny power stations in every cell of the body called mitochondria.
One in every 6,500 babies are born with severe mitochondrial disease which means they have insufficient energy to function - it leads to muscle weakness, blindness, heart failure and even death.
Mitochondria are passed only from mother to child.
A scientific panel, assembled by the Human Fertilisation and Embryology Authority (HFEA), assessed two advanced forms of IVF using material from three people - the parents to be and a woman with healthy mitochondria.
Prof Robin Lovell-Badge, from the Medical Research Council and a member of the scientific panel, said: 'The direction of travel still suggests that it is all safe, but we don't know what's round the corner so we're being a little cautious.'
The HFEA report called for a series of final tests before either of the procedures could be performed.
'I think that [two years] is not a bad estimation. The other sorts of experiments that we thought were necessary again it will take about two years to complete all of those.'
A Department of Health spokesperson said: 'Mitochondrial donation will give women who carry severe mitochondrial disease the opportunity to have children without passing on devastating genetic disorders.
'It will also keep the UK at the forefront of scientific development in this area.
'We will give careful consideration to this report together with the responses to our recent consultation and announce our plans in the next few months.'