A recent study published in BMJ Medicine indicates that the 2013 World Health Organization (WHO) criteria for diagnosing gestational diabetes mellitus (GDM) may have low sensitivity when evaluating a 75 g oral glucose tolerance test (OGTT) in early pregnancies. Changes in screening thresholds have contributed to the observed increase in the prevalence of pregnancies affected by GDM, which can range from 2% to 30% worldwide.
The diagnosis of GDM is based on the risk of adverse outcomes for the baby, which are associated with maternal hyperglycemia. The 75 g OGTT is commonly used to determine maternal hyperglycemia around 24 to 28 weeks of gestation. The diagnostic cutoffs for fasting glucose concentrations, 1-hour postload plasma glucose concentrations, and 2-hour concentrations were established by the WHO in 2013.
To assess the effectiveness of the WHO 2013 criteria in early pregnancy, a multicenter cohort study was conducted. The study participants were pregnant women between the ages of 18 and 45 who were undergoing first trimester screening. The study excluded women with pre-existing diabetes or chronic diseases, as well as those taking certain medications. The data collected from the participants included family history, weight, height, urine dipstick, blood pressure, and medical complications.
The results of the study demonstrated that the WHO 2013 criteria had a low sensitivity and high specificity in early pregnancy. Out of the 636 participants included in the analysis, only 12% were diagnosed with GDM using a later OGTT. Participants who were diagnosed with GDM at 24 to 28 weeks of gestation often had higher glucose levels in the early OGTT.
These findings suggest a need for modifying the WHO 2013 criteria to improve the detection of GDM in early pregnancy. This could potentially lead to better management through early lifestyle and drug interventions. Further research is recommended to validate these findings in different populations and explore the effects of early interventions.
Reference:
Huhn EA, Göbl CS, Fischer T, et al. Sensitivity, specificity, and diagnostic accuracy of WHO 2013 criteria for diagnosis of gestational diabetes mellitus in low-risk early pregnancies: international, prospective, multicentre cohort study. BMJ Med. 2023;2(1):e000330. doi:10.1136/bmjmed-2022-000330
