Women who develop gestational diabetes mellitus (GDM) run a significant risk of developing type 2 diabetes later in life if they are obese or put on weight after the pregnancy.
Researchers at the US National Institutes of Health tracked 1695 women with incident GDM between 1991 and 2001 over a mean follow-up of 13.1 years. Of these participants, 259 developed type 2 diabetes. Both those who were obese when diagnosed with GDM and those who gained weight after pregnancy had an increased risk of developing the condition.
After adjustment for age, parity and general risk factors for diabetes, the hazard ratio (HR) for type 2 diabetes was 1.16 for each 1 kg/m2 increase in BMI, both at baseline (95% confidence interval [CI], 1.12–1.19) and at final follow-up (95% CI, 1.13–1.20). Furthermore, each 5 kg/m2 increase in weight following GDM diagnosis conferred a 27% increased risk of the condition (HR, 1.27; 95% CI, 1.04–1.54). Women who were both obese at baseline and gained ≥5 kg thereafter fared the worst, with an HR of 43.19 (95% CI, 13.60–137.11) compared with normal-weight women who gained <5 kg.
The authors of the study said: “Our findings provide evidence to support the recent call from the National Diabetes Education Program and highlight the importance of achieving and maintaining a healthy weight in these high-risk women to prevent future development of type 2 diabetes.”
Janet Fyle, professional policy advisor at the Royal College of Midwives, said that the findings highlight the need to dispel the myth about eating for two during pregnancy.
The study, published in Diabetologia, can be found here.