The duration of labour, the need for assisted delivery, and caesarean rates were all unaffected by munching between contractions, found the study, published by the British Medical Journal.

Doctors the world over have long discouraged women in labour from eating, for fear that it could lead to breathing food into the lungs in the case of an emergency caesarean while under general anaesthetic.

But such incidents have declined dramatically in recent years, mainly due to the use of local anaesthesia.

Moreover, some doctors have long argued that fasting while in labour – which can last many, many hours – may be bad for the mother and the baby.

Studies to date have been inconclusive, so a research team led by Professor Andrew Shennan at King's College London investigated the effect of eating during labour on delivery rates.

The study split 2,426 first-time healthy mothers into two groups. The first was only allowed to drink water, the usual practice.