It is possible to imagine a scenario where a woman goes on maternity leave four weeks before her confinement date because she has to. If her pregnancy goes to 42 weeks she will have been sitting at home – perhaps twiddling her thumbs because it might be her first baby – for six weeks. When the baby comes, she finds she has to go back to work much sooner than she intended. She would have preferred to have had all that time after the birth. Some people have said that to change that would take away women's rights.