But increasingly, childless men are viewed with suspicion. Remember that faintly desperate Gordon Brown photo opportunity, arranged in the days before he had children of his own, involving him at the birthday party of a small child of a staff member? Borrowing someone else’s kid was clearly preferable to the risk of being portrayed as a workaholic loner, incapable of sharing his life.

And the greatest taboo of all remains confessing to being child-free not by accident but by choice. Stories of infertility, miscarriage or just never having found the right person do at least evoke sympathy. The bile heaped on the former Australian prime minister Julia Gillard for being what her critics called “deliberately barren” is a reminder of how often the mature, considered choice not to have children is portrayed as cold and heartless.

It’s true that parents sacrifice sleep, sanity and the distant memory of having once had plans of their own in return for stinking nappies, a houseful of plastic tat and the chance to provide a free taxi service for grunting ingrates. In a strict economic sense, our children are a public good; falling fertility rates in Italy, as in other countries, have shrunk the tax base alarmingly at a time when workers must support historically unprecedented numbers of older people through their retirement. (Although evidence from Scandinavia, where fertility rates are markedly higher than in the traditionally Catholic south of Europe, suggests that providing good cheap childcare and getting men to share the parenting does more to encourage large families than a scolding from the church.)