GESTATIONAL DIABETES MELLITUS (BASED ON THE RESULTS OF A SCREENING STUDY IN THE MOSCOW REGION)

Background: New diagnostic criteria for gestational diabetes mellitus (GDM) are being currently implemented into clinical practice. GDM prevalence and pregnancy outcomes in women with GDM diagnosed according to the new criteria have not been studied in Russia.

Aim: To evaluate prevalence of GDM and pregnancy outcomes in women with GDM based on the Russian consensus criteria 2012 ("Gestational diabetes mellitus: diagnosis, treatment and postpartum follow-up") in the population of the Moscow Region.

Materials and methods: The study included 176 pregnant women living in the Moscow Region. We retrospectively analyzed 100  pregnant women (mean age±SD  – 28.3±6 years) who delivered before 2013 with collection of data on blood glucose and gestational age of its measurement, body mass index (BMI) at conception and pregnancy outcomes. The prospective part of the study conducted from January to July  2015 included screening of 820  pregnant women helped to identify 76 cases of GDM (mean age±SD – 30.4±5.5 years); their follow-up included monitoring of glucose levels, gestational term, and pregnancy outcomes.

Results: In the retrospective part of the study, 19  women (19%) were identified with their fasting glucose levels≥5.1  mmol/L (5.39±0.29  mmol/L) at 14.4±9.3  weeks of gestation, that corresponds to diagnosis of GDM with 2012 criteria. The comparison of pregnant women with and without fasting hyperglycemia showed no difference in age and pre-pregnancy BMI values. Women with fasting hyperglycemia had high total rates of adverse pregnancy outcomes than those without (52.6%  vs 24.6%, respectively, p<0.017), as well as higher rates of fetal asphyxia during delivery and clavicle fractures (15.8%  vs 3.7%, p=0.04 and 10.5% vs 0%, p=0.03). In the prospective part of the study, 820  pregnant women were screened for GDM, and it was found in 76 (9.2%) of them. Among those, in 50 (65.8%) the diagnosis of GDM was based on fasting glucose in venous plasma (5.5±0.3 mmol/L) at 11.3±6.1 weeks of gestation. Pregnant patients with fasting hyperglycemia in the retrospective and prospective parts of the study did not differ in their age, pre-pregnancy BMI, fasting glucose levels and terms of assessment; however, in the prospective study, the rate of fasting hyperglycemia was lower than in the retrospective (6% vs 19%). The second phase of the screening performed at 20 to 30 weeks of gestation helped to identify 26  women (34.2%) with GDM: in 15 of them (19.7%) the diagnosis was based on repeatedly high fasting glucose (5.5±0.3 mmol/L) and in 11 (14.5%), on the results of the oral glucose tolerance test. To all pregnant women with GDM, diet and blood glucose self-monitoring were recommended. Pregnancy outcomes were assessed in 64 GDM patients, with their comparison in compliant patients (n=30) vs non-compliant (n=34). Patients with poor compliance had higher rates of preterm delivery (11.4% vs 0%, р=0.05), macrosomia (32.3%  vs 6.6%, р=0.01) and other adverse outcomes (76.5% vs 50%, р=0.03) than those with good compliance.

Conclusion: The prevalence of GDM in a district of the Moscow Region in the prospective study was 9.2%. The retrospective analysis showed an overestimated rate of fasting hyperglycemia (19%). In the majority of GDM patients, the diagnosis was based on an increased fasting glucose level in venous plasma (85.5%). Treatment of GDM patients helps to reduce adverse pregnancy outcomes.