Women must take care to pursue a healthy and balanced diet during pregnancy and breastfeeding, the Royal College of Midwives has said.
According to spokesman Tony Koutsoumbo, pregnant women should eat plenty of fruit and vegetables, although the occasional treat is not out of the question as long as it does not involved un-pasteurised cheese, rare meat or unwashed vegetables.
"It is important to maintain a healthy diet, which means avoiding junk food and alcohol," he advised.
Mr Koutsoumbo also pointed out that some women experience cravings for different foods during pregnancy, as well as changes in appetite.
"Giving in to the occasional treat - as long as it is safe - is okay," he insisted.
Pregnant women should also not be overly concerned about weight gain, as long as they are eating healthily.
The average mum-to-be puts on between 18 and 32 pounds during pregnancy, according to babycentre.co.uk, but Mr Koutsoumbo said that media pressure leads many new mothers to slim down immediately after the birth.
"Women need to follow a similar diet while feeding as they did in pregnancy," he said, adding that those who feel under pressure to lose weight should seek individual care and advice to reassure them about their weight.
Women who are planning a baby are advised to take 400mcg of folic acid daily, both while they are trying to conceive and up until the 12th week of pregnancy.