The number of women with diabetes attending the nutrition department of the Rotunda maternity hospital in Dublin rose by 52pc between 2005-2011.
Due to the increase in demand for the service, the dietician has had to prioritise patient referrals for higher-risk patients, according to its annual report.
The National Maternity Hospital also reported that the numbers of new referrals of women with various kinds of diabetes increased from 53 in 2010 to 113 in 2011.
Women with diabetes are at higher risk of having problems during pregnancy and labour, including stillbirth. They also have a greater chance of premature birth, and having a large baby.
For women who intend to get pregnant, the advice is to ensure they have close control of blood sugar levels.
Poor control during the first eight weeks of pregnancy increases the risk that the baby will have serious health problems.
Women can also develop a disease in pregnancy called gestational diabetes.
Risk factors include being overweight or obese, having previously given birth to a very large baby, and having gestational diabetes in a previous pregnancy.
Gestational diabetes goes away after a woman has the baby, but it does increase her risk of having diabetes later.
Dr Rhona Mahony, master of Holles Street, told Health & Living that 38pc of the 9,500 mothers who will give birth in Holles Street this year will be overweight.
"One in 10 will be obese and 1pc morbidly obese, leading to complications including higher levels of sugar in the blood which can be passed on to their baby.
"Women are advised to eat slow-release carbohydrates to try to keep from gaining too much weight during pregnancy."
Commenting generally on nutrition during pregnancy, Dr Mahony said pregnancy cravings were not a myth and one patient at the hospital was found to be drinking 30 cans of Coca-Cola a day.
"She became ill and we did not know what was wrong, but then found out about the cola intake."