Non-efficacy of early intervention strategy for non-obese patients with early-onset gestational diabetes mellitus: solely based on the short-term outcomes

INTRODUCTION: To verify the effectiveness of intervention in early pregnancy for women with early-onset gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: This study included women with a singleton pregnancy who were diagnosed with early-onset GDM by 20 weeks of gestation according to the International Association of Diabetes and Pregnancy Study Group (IADPSG) threshold. We retrospectively evaluated the pregnancy outcomes in pregnant women with early-onset GDM. In the treatment from early pregnancy group (n=286), patients were diagnosed with early-onset GDM at the Yokohama City University Medical Center (YCU-MC) in 2015–2017 and were treated for GDM from early pregnancy. Concerning the treatment from mid-pregnancy group (n=248), participants were diagnosed with early-onset GDM at five sites, including the YCU-MC in 2018–2019, and were followed up without treatment until the second 75 g oral glucose tolerance test (OGTT) at 24–28 weeks of gestation. Treatment for GDM was given only if the GDM pattern was still present in the second OGTT. RESULTS: There were no significant differences in maternal backgrounds, including GDM risk factors and gestational weight gain, between the groups. Among the treatment from mid-pregnancy group, the false-positive early GDM was 124/248 (50%). Regarding pregnancy outcome, the rate of large for gestational age (LGA) was 8.8% in the treatment from early pregnancy group and 10% in the treatment from mid-pregnancy group, with no significant difference, whereas small for gestational age (SGA) was significantly higher in the treatment from early pregnancy group (9.4%) than in the treatment from mid-pregnancy group (4.8%) (p=0.046). There were no significant differences in maternal adverse events and neonatal outcomes between the groups. In a subanalysis limited to body mass index >25 kg/m(2), LGA was significantly lower in the treatment from early pregnancy group than in the treatment from mid-pregnancy group. CONCLUSIONS: The strategy for diagnosing GDM by IADPSG thresholds in early pregnancy and providing treatment to all patients from early pregnancy did not improve the pregnancy outcomes, but rather increased the SGA rate.