Some doctors do not advise eating during labour
It is safe for most healthy women to eat during labour, research has found.
The study found eating a light diet during labour has no effect on the duration of labour, the need for assisted delivery, or Caesarean rates.
Since the 1940s it has been common practice to prevent eating during labour to cut the risk of complications if surgery is required.
But the King's College London study, featured online in the British Medical Journal, suggests this is too cautious.
Some doctors have previously advised women not to eat during labour to minimise the risk that they would breathe food into their lungs should they need an emergency caesarean under general anaesthetic - a condition known as pulmonary aspiration.
But pulmonary aspiration has declined dramatically in recent years, mainly due to the increased use of local anaesthesia for caesarean deliveries.
Many doctors and midwives also argue that preventing food intake during labour can be detrimental to the mother, her baby and the progress of the delivery.
However, previous research on the subject has proved inconclusive.
The King's team focused on 2,426 healthy women having their first baby. Each women was either allowed small, regular amounts of food during labour, such as bread, fruit and yoghurt, or water only.
The natural birth rate in both groups was the same, at 44%. Average duration of labour was also similar, 597 minutes for the eating group, and 612 minutes for the water only group.
The caesarean rate was also the same - 29% for the eating group, and 30% for the water group.
And in both groups around one in three women vomited during labour.
There were also no differences in the condition of the babies at birth or admission to special care units.
The researchers, led by Professor Andrew Shennan, said the study showed that there was no pressing reason to deny women food during labour.
They wrote: "Denial of food can be seen as authoritarian and intimidating, which may for some women increase feelings of fear and apprehension during labour.
"Eating and drinking may allow mothers to feel normal and healthy."
Current guidelines from the National Institute for Clinical Excellence (NICE) recommend that low risk women in normal labour may eat and drink.
Dr Virginia Beckett, a consultant obstetrician and spokesperson for the Royal College of Obstetricians and Gynaecologists, said it was fine for healthy women at low risk to eat during labour.
But she stressed that it was not a good idea for those who were at higher risk, such as women who were obese.
Women using pethidine to reduce pain during labour, should also avoid food, as the drug relaxed the gut muscles, making problems more likely.
Dr Beckett said: "Eating during labour is not going to make things better, but it is not going to make things worse, and it might make you feel more of a human being, and that is quite important.
"We would not want women to be sitting there eating a roast dinner, but it is reasonable to suggest it is safe for low-risk women to eat small amounts of preferably liquid food during labour."