If the old adages are to be believed, a hot curry or having sex can help overdue pregnant women go into labour.
But researchers have found another solution – touching the nipples for one hour a day, three days in a row.
Researchers found breast and nipple stimulation could be likely to induce labour as it naturally produces the "cuddle hormone" oxytocin – which is often administered by medics to speed up delivery.
Writing in the journal PLOS ONE, scientists from St Luke’s International University, Tokyo, found that in six trials involving 719 women, nipple stimulation triggered the earlier onset of labour.
In a previous study published in Birth, 201 women were asked if they tried to induce labour naturally at home. Of the group, about half said they tried at least one method, such as eating spicy food or having sex.