There is accumulating evidence that gestational diabetes is a growing problem. The lack of internationally standardized diagnostic procedures prevents consistent diagnosis and the burden of gestational diabetes must be determined in country-specific studies. In southern Sweden, gestational diabetes is defined as a 2-h capillary plasma glucose concentration of ≥10.0 mmol/L during a universal 75-g oral glucose tolerance test. We report the crude prevalence of gestational diabetes during the years 2003-2012. Of 156 144 women who gave birth, 2.2% were diagnosed with gestational diabetes. When the effect of time on the prevalence of gestational diabetes was assessed in a log-linear Poisson model, an overall increase in prevalence of 35% was predicted, corresponding to an average annual increase of 3.4%. Predicted prevalence was 1.9 (95% CI 1.8-2.0) in 2003 and 2.6 (95% CI 2.4-2.7) in 2012 (p < 0.0001). Due to a simultaneous rise in birth rate, the number of women diagnosed with gestational diabetes increased by 64%.

Decentralised general OGTT is a reliable and effective method to diagnose GDM. OGTT is twice as sensitive as RGM, and the severity of GDM in the cases identified with OGTT did not differ from the severity of those identified with RGM.

The TCF7L2 rs7903146 and FTO rs8050136 polymorphisms, and particularly a weighted risk score of T2D risk alleles, predict diabetes after GDM. Further studies in other populations are needed to confirm our results.

these data indicate that even limited degrees of maternal hyperglycemia may affect the outcome of pregnancy.