Babies born to mothers with gestational diabetes have more body fat when they reach two months of age compared to babies born to mothers without the condition, a new study has found.

This marks the first study to show that gestational diabetes causes such early changes in the baby, despite there being no differences in body fat levels at the time of birth.

Gestational diabetes is a type of diabetes that develops during pregnancy - most often in the second or third trimester. It results in a woman's blood sugar levels becoming too high. It usually disappears after the baby is born, although women who develop it are at an increased risk of developing type 2 diabetes later on.

Scientists in the UK carried out MRI scans on 86 babies in order to measure the amount of body fat they had. They did this shortly after birth and again eight to 12 weeks later.

The study found no differences in body fat levels at the time of birth. However, by the time the children had reached two months of age, those born to mothers with gestational diabetes had 16% more body fat compared those born to women without the condition.

While it is unknown why this occurs, the scientists said that it could be down to changes in the baby's metabolism while they are still in the womb. They also suggested that it could be down to differences in the composition of breast milk in mothers with this condition, as most of the babies in the study were breastfed.

"The majority of babies in our study were breastfed, and previous studies have suggested that diabetes may cause changes in breast milk - so that it contains more sugar, fat or different levels of compounds that control appetite, called hunger hormones," commented the study's senior author, Prof Neena Modi, of Imperial College London.

Meanwhile, according to the study's lead author, Dr Karen Logan, as gestational diabetes is becoming more and more common, and babies born to these mothers are at an increased risk of developing diabetes themselves when they grow up, ‘we need to understand what effects maternal diabetes has on the baby'.

"This new study suggests diabetes in the mother can trigger changes in the baby at a very early stage," she said.

She noted that while excess weight is one of the main causes of gestational diabetes, there are other causes too and in fact, many of the women in this study were a healthy weight.

"Many of the women in our study were not overweight, and there are other possible causes of the condition, such as genetic predisposition. All of the women in the study had their condition well-controlled, however this study suggests that even good treatment during pregnancy may not be enough to prevent longer term problems in the baby," Dr Logan said.

Details of these findings are published in the journal, Diabetes Care.