Despite the hundreds of thousands of babies born every day, we still know relatively little about childbirth and how hormones play their key roles in it. A stress hormone, known as cortisol, is involved in inducing labour in animals, but doesn't seem to work the same way in people. A paper this week published in Science Signalling has suggested a potential way cortisol does have a part to play in human childbirth. Georgia Mills caught up with Professor Joe Herbert, from Cambridge University, to discuss the study. Like this podcast? Please help us by supporting the Naked Scientists