Global estimates of the prevalence of hyperglycaemia in pregnancy

Aims: We estimated the number of live births worldwide and by IDF Region who developed hyperglycaemia in pregnancy in 2013, including total diabetes in pregnancy (known and previously undiagnosed diabetes) and gestational diabetes.

Methods: Studies reporting prevalence of hyperglycaemia first-detected in pregnancy (formerly termed gestational diabetes) were identified using PubMed and through a review of cited literature. A simple scoring system was developed to characterise studies on diagnostic criteria, year study was conducted, study design, and representation. The highest scoring studies by country with sufficient detail on methodology for characterisation and reporting at least three age-groups were selected for inclusion. Forty-seven studies from 34 countries were used to calculate age-specific prevalence of hyperglycaemia first-detected in pregnancy in women 20-49 years. Adjustments were then made to account for heterogeneity in screening method and blood glucose diagnostic threshold in studies and also to align with recently published diagnostic criteria as defined by the WHO for hyperglycaemia first detected in pregnancy. Prevalence rates were applied to fertility and population estimates to determine regional and global prevalence of hyperglycaemia in pregnancy for 2013. An estimate of the proportion of cases of hyperglycaemia in pregnancy due to total diabetes in pregnancy was calculated using age- and sex-specific estimates of diabetes from the IDF Diabetes Atlas and applied to age-specific fertility rates.

Results: The global prevalence of hyperglycaemia in pregnancy in women (20-49 years) is 16.9%, or 21.4 million live births in 2013. An estimated 16.0% of those cases may be due to total diabetes in pregnancy. The highest prevalence was found in the South-East Asia Region at 25.0% compared with 10.4% in the North America and Caribbean Region. More than 90% of cases of hyperglycaemia in pregnancy are estimated to occur in low- and middle-income countries.

Conclusion: These are the first global estimates of hyperglycaemia in pregnancy and conform to the new WHO recommendations regarding diagnosis and also include estimates of live births in women with known diabetes. They indicate the importance of the disease from a public health and maternal and child health perspective, particularly in developing countries.