Ultrasonic predictors of macrosomia in gestational diabetes mellitus

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 (Р<0,05). 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

Birth weight and length in offsprings of mothers with gestational diabetes mellitus due to mutations in GCK gene

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