The United Kingdom’s fertility regulator on Wednesday confirmed the births of the UK’s first babies created using an experimental technique combining DNA from three people, an effort to prevent the children from inheriting rare genetic diseases.

The UK’s Human Fertilisation and Embryology Authority said fewer than five babies have been born this way in the UK but did not provide further details to protect the families’ identities. The news was first reported by the Guardian newspaper.

In 2015, the UK became the world’s first country to adopt legislation specifically regulating methods to help prevent women with faulty mitochondria – the energy source in a cell – from passing defects on to their babies.

The genetic defects can result in diseases such as muscular dystrophy, epilepsy, heart problems and intellectual disabilities. About one in 200 children in the UK is born with a mitochondrial disorder. To date, 32 patients have been authorised to receive such treatment.