Analysis of the Japanese gestational diabetes mellitus diagnostic strategy during the coronavirus disease 2019 pandemic using DREAMBee study data

Aims/Introduction: We evaluated a simple diagnostic gestational diabetes mellitus (GDM) strategy (Japanese COVID-19 GDM strategy) published by the Japanese Society of Diabetes and Pregnancy using GDM group data from the Diabetes and Pregnancy Outcomes for Mother and Baby (DREAMBee) study. Materials and Methods: The study included 803 mothers with GDM diagnosed after 24 gestational weeks using an oral glucose tolerance test and 1,356 with normal glucose tolerance (NGT) from the DREMBee study. They were reclassified by the Japanese COVID-19 GDM strategies (COVID-19 GDM and COVID-19 NGT) using glycated hemoglobin (HbA1c) and random plasma glucose or fasting plasma glucose (FPG) levels. We evaluated the usefulness of the Japanese COVID-19 GDM strategy and investigated the parameters for diagnosing GDM managed with insulin therapy. Results: Participants (n = 2,159) were assigned to COVID-19 GDM (n = 413) and COVID-19 NGT (n = 1,746) groups. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Japanese COVID-19 GDM strategy were 35.4, 90.5, 68.9, and 70.3%, respectively. When the risk factors for insulin therapy were analyzed using a regression model, HbA1c and FPG levels were risk factors for GDM with insulin therapy (P < 0.0001). The cut-off value of HbA1c was 5.4% (sensitivity, 0.69; specificity, 0.66; PPV, 0.11; NPV, 0.97), and that of FPG was 86 mg/dL (sensitivity, 0.60; specificity, 0.77; PPV, 0.16; NPV, 0.96). Conclusions: The Japanese COVID-19 GDM strategy for GDM diagnosis after 24 weeks of gestation might be useful in emergency situations. However, further analysis of GDM outcomes diagnosed using this approach is necessary.