Background: The prevalence of MODY2 in the gestational diabetic population has been estimated to be approximately 2%. Risk of macrosomia in GCK/GDM cases depends on maternal glycemic control and fetal mutation status. However, the fetal genotype is unknown before birth. We assessed the effects of insulin therapy on the birth weight of children born to mothers with GCK mutations.
Objective and hypotheses: The study included 38 patients with GDM due to GCK gene mutations and their 38 offsprings (22 affected children and 16 unaffected). All participants were divided into 2 groups depending on offsprings genotype. All women during pregnancy were treated with insulin.
Results: The median birthweight in affected children was 3125 g [2800; 3300], in unaffected, 3550 g [2930; 3890], P=0.036, nevertheless the weight remained in the normal range for gestational age. Among unaffected children diabetic fetopathy was observed in 6 (37.5%) newborns, including one child born at week 31 with weight +2.3 SD. Two affected children had low birth weight. Insulin therapy in these cases was started early (57 weeks) with achievement of strict glycemic control and episodes of hypoglycemia.
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.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology