Children as young as 12 are to be allowed drugs to block puberty while they decide whether to have a sex change, it has been revealed. The monthly injection suspends the onset of adulthood so that young people confused about their gender can be sure of any decision before they take on too many masculine or feminine features. Supporters say that the "window" prevents a great deal of mental and physical anguish caused by the maturing of sex organs, facial hair growth and changes in the voice. But critics argue it only prolongs the agony and can prevent people "growing...