Single men and women without medical issues will be classed as “infertile” if they do not have children but want to become a parent, the World Health Organisation is to announce.

In a move which dramatically changes the definition of infertility, the WHO will declare that it should no longer be regarded as simply a medical condition.

The authors of the new global standards said the revised definition gave every individual “the right to reproduce”.

Until now, the WHO’s definition of infertility – which it classes as a disability – has been the failure to achieve pregnancy after 12 months or more of regular unprotected sex.