I suppose that we are messing about with nature all the time when we undertake interventions - transplants and IVF, as you say, also drugs to cure diseases, contraception, blood transfusions, surgery, vaccinations, anaesthesia (and pain relief in childbirth was once thought unnatural - "in pain shalt thou travail and bring forth children" - Queen Victoria decided that she was not amused by suffering in her first seven deliveries and took chloroform during her eighth)
What would be the worst figure of speech if you took them literally?
French school children on strike
if you still listen to public broadcasters local radio,your in for a shock

