Following the chief medical officer, Professor Dame Sally Davies apocalyptic report comparing the threat of antibiotic resistance to terrorism, Dr Mark Porter looks at the overuse of antibiotics. He asks is it even useful to ask if an infection is viral or bacterial - are antibiotics the right thing even in a bad, bacterial infection? 60,000 pregnant women will go into premature labour every year in the UK. Mark visits a pioneering clinic at St Thomas's hospital in London to prevent premature labour. He also asks do all women need smear tests even if they're in long term monogamous relationships, have always had clear tests or are in a lesbian relationship? And aspirin to prevent the risk of stroke after hip replacements.