A sound way towards reversible vasectomies

THE MOST reliable means of contraception for men—and one that cannot fail or be forgone in the heat of the moment—is a vasectomy. But the procedure is largely irreversible: it involves stopping the flow of sperm from the testes by cutting conduits known as the and sealing them or tying them off. A reconnection, after a reconsideration, is no small task.Researchers are now examining a different tack: blocking the using compounds that combine to form a barrier that can later be removed. Lab trials have involved four separate injections to establish a sperm-proof barrier, which could later be dissolved using a blast of focused, infrared light.