Bid to Delay ‘Three Parent Babies’ Through IVF as Tests Find Fears Could Suffer Reduced Fertility, Learning Difficulties and even Cancer

Legislation to allow the birth of babies with genes from three biological parents should be put on hold because it is far riskier than previously thought, scientists warn.

MPs are due to vote on whether the UK should become the first country to legalise controversial ‘three parent babies’ after Government watchdog the Human Fertilisation and Embryology Authority (HFEA) gave it the go-ahead.

Advocates have compared the IVF technique, which involves inserting a small set of genes from a second mother, to ‘changing a battery’, saying it had no real impact on the baby’s core DNA.

But a growing number of scientists and MPs say new research indicates that such children’s genetic make-up could be affected far more profoundly than had been realised and they may develop unpredictable physical and mental character traits. They say that tests on animals have fuelled fears that people born using this technique – called mitochondrial DNA transfer – could also face problems such as reduced fertility, shorter lives, learning difficulties and cancer.

Even the respected New Scientist, which had backed the technique, last...