Exasperated mothers often warn that their children “will be the death of them”, and a new study suggests there may be some truth in the admonishment. Pregnancy accelerates biological ageing, with each baby causing women to grow older by up to 2.8 months, scientists have discovered. Carrying a child is known to have long-term health impacts, but previous studies have found they are largely beneficial, such as lowering the risk of cancer and dementia. Now new research by Columbia University