Obese mothers who develop gestational diabetes while pregnant and put on more weight after giving birth are 43 times more likely to develop type 2 diabetes compared to leaner women, results of an 18 year study show. 

The analysis of 1,695 women with gestational diabetes (GDM) identified  259 cases of type 2 diabetes (T2D) during up to 18 years of follow-up.

For every one unit (1 kg/m2) in either baseline BMI or most recent BMI there was a 16% increased risk of developing type 2 diabetes, the authors from the US National Institutes of Health reported in Diabetologia.

Each 5 kg increment of weight gain after GDM development was associated with a 27% higher risk of T2D.

And women with a BMI of 30 or higher who had gained 5 kg or more after GDM had a 43-times increased risk of developing T2D compared with women who had a BMI of 25 or less at baseline and gained 5 kg or less after GDM.

The positive associations of BMI and weight change with risk of type 2 diabetes were robust and persisted across different categories of age, family history of diabetes, diet quality, physical activity, breastfeeding duration and time since GDM pregnancy, the researchers said.

The findings highlight the importance of achieving and maintaining a healthy weight in these at risk women, the researchers concluded.