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BACKGROUND: The basis of early ultrasound (US) diagnosis of diabetic fetopathy (DF) in pregnant with gestational diabetes mellitus (GDM) is the forehanded detection of macrosomia, especially its asymmetric forms. In pregnant with GDM on a diet therapy, the detection of macrosomia may be an indication for starting the insulin therapy. In pregnant with hyperglycemia due to mutation in the glucokinase gene (GCK), US fetal growth dynamics helps to assume the fetal genotype, as well as to stratify the risks of insulin therapy. AIM: To determine the prognostic significance of asymmetric form of macrosomia and the value of the coefficients of proportionality for the diagnosis of DF in pregnant with GDM, including hyperglycemia due to mutation in the GCK gene. MATERIALS AND METHODS: US fetometry was performed in 95 pregnant with GDM (including 22 pregnant with hyperglycemia caused by mutation in the GCK gene) (main group) and 427 healthy pregnant women (control group). Estimated fetal weight, standard fetometric indicators and coefficients of proportionality were evaluated. Retrospective analysis of US predictors of macrosomia was carried out after evaluating the weight of the newborn and clarifying the signs of DF. RESULTS: In the group with GDM, 51 (53.7%) pregnant had children with phenotypic symptoms of DF, including macrosomia 66,7% (34 children). We found statistically significant differences in fetal weight between the control group and the main group who gave birth to children with DF starting from 32 weeks. The coefficients of proportionality (femur length/abdominal circumference and the head circumference/abdominal circumference), characterizing the formation of the asymmetric macrosomia were significantly from 34 weeks (Р0,05). CONCLUSION: The most effective predictive fetometric indicators for the diagnosis of fetal macrosomia are the dimensions of fetal abdomen and fetal weight 90 percentile for gestational age. A specific sign of DF in pregnant with GDM is the asymmetric macrosomia. In pregnant with a mutation in the GCK gene, the tendency to macrosomia was revealed only in the absence of a mutation in the fetus, but insulin therapy in the presence of a similar mutation in fetus did not lead to a significant decrease in its percentile ranges.

MODY1 and MODY3 represent rare causes of diabetes in pregnancy. Establishing a molecular diagnosis of MODY1 or MODY3 during pregnancy may be important for minimizing risk of perinatal complications and for improving glycemic control after pregnancy. The objective of the study was to evaluate the contribution of mutations in HNF4A and HNF1A genes in development of diabetes in pregnancy and to describe clinical characteristics of diabetes in pregnancy associated with these mutations. 230 pregnant women (20-43 years) with different type of glucose intolerance complicated during their current pregnancy were included in the study. A custom NGS panel targeting 28 diabetes causative genes was used for sequencing. Heterozygous mutations in HNF4A and HNF1A genes were detected in 3% of cases. Mutations p.I271T in HNF4A gene and p.L148F, p.Y265C, p.G288W in HNF1A gene were novel. This study includes a description of patients with pregnancy diabetes due to mutations in hepatocyte nuclear factors.

Diabetes in pregnancy may be associated with monogenic defects of beta-cell function, frequency of which depends on ethnicity, clinical criteria for selection of patients as well as methods used for genetic analysis. The aim was to evaluate the contribution and molecular spectrum of mutations among genes associated with monogenic diabetes in non-obese Russian patients with diabetes in pregnancy using the next-generation sequencing (NGS). 188 non-obese pregnant women with diabetes during pregnancy were included in the study; among them 57 subjects (30.3%) met the American Diabetes Association (ADA) criteria of preexisting pregestational diabetes (pre-GDM), whereas 131 women (69.7%) fulfilled criteria of gestational diabetes mellitus (GDM). A custom NGS panel targeting 28 diabetes causative genes was used for sequencing. The sequence variants were rated according to the American College of Medical Genetics and Genomics (ACMG) guidelines. In total, 23 pathogenic, 18 likely pathogenic and 16 variants of uncertain significance were identified in 59/188 patients (31.4%). The majority of variants (38/59) were found in GCK gene. No significant differences in the number of variants among the two study groups (pre-GDM and GDM) were observed. The study suggests that frequency of monogenic variants of diabetes might be underestimated, which warrants a broader use of genetic testing, especially in pregnancy.

Background. Gestational diabetes (GDM) due to GCK gene mutations is the most frequent form of monogenic diabetes mellitus (DM) presenting during pregnancy. It has been suggested that the use of insulin in pregnancies with fetuses carrying GCK mutations may lead to intrauterine growth retardation. In the present study we evaluated the effect of insulin therapy during pregnancy on birth weight and length in the offsprings of mothers with GDM due to GCK mutations. Aims. The aim was to study birth weight and length in offsprings of mothers with gestational diabetes mellitus due to mutations in GCK, depending on the therapy during pregnancy. Materials and methods. The study included 38 patients with GDM caused by GCK gene mutations (18.7%) and the 45 offsprings. To define molecular basis of GDM in pregnant women we used a targeted NGS. Diabetes panel genes were sequenced using a custom Ion Ampliseq gene panel and PGM semiconductor sequencer (Ion Torrent). To found the same mutations in their offsprings was used Sanger sequencing. All children were divided into 3 groups depending of their genotype and therapy received by the mothers during pregnancy. Results. We found statistically significant differences in birth length (p=0.04) and weight (p=0,031) depending on the genotype of the child and therapy in the mother. The risk of macrosomia was shown in non-mutation-carrying offsprings only. The birth weight in children with GCK gene mutations whose mothers received insulin during pregnancy was significantly lower. However, the birth weight remained in the normal range. Conclusions. Since prenatal diagnostics in the mothers with GCK gene mutations is not always justified, we recommend insulin therapy in order to prevent fetal macrosomia, which, however, should be less aggressive than in GDM due to other causes.