The finding comes as NICE announced plans to issue advice on weight management in pregnancy, to dispel myths about the need to 'eat for two' or drink full-fat milk.

Kaiser Permanente researchers examined data on weight gain in 1,145 pregnant women up to their first screening for gestational diabetes at 24-28 weeks.

They divided the women into those who had gained below, within or above current US recommendations for weight gain during pregnancy (12.5-18kg for BMI less than 19.8; 11.5-16kg for BMI of 19.8-26; and 7-11.5kg for BMI more than 26).

Women who gained more weight than recommended had a 50 per cent higher risk of developing gestational diabetes.

This association between weight gain during pregnancy and gestational diabetes was more pronounced among overweight and non-white women.

Previous studies have shown a link between weight gain before pregnancy and developing gestational diabetes. But the researchers believe this is one of the first to support a direct association between weight gain in pregnancy and the risk of developing gestational diabetes.

'Our research shows weight gain in early pregnancy is a modifiable risk factor for gestational diabetes,' the study's lead author Dr Monique Hedderson said.

Comments on the NICE recommendations can be made via NICE's website until 18 March.