Flexible treatment of Gestational Diabetes modulated on ultrasound evaluation of intrauterine growth: a controlled randomized clinical trial

Objectives: In order to prevent abnormalities of fetal growth still characterizing pregnancies complicated by Gestational Diabetes (GDM), in the present study we evaluated a therapeutic strategy for GDM based on ultrasound (US) measurement of fetal insulin-sensitive tissues. Methods: All GDM women diagnosed before 28th week immediately started diet and self-monitoring of blood glucose; after 2 weeks they were randomized to conventional (C) or modified (M) management. In C the glycemic target (GT) was fixed at 90 fasting/120 post-prandial mg/dl; in M GT varied, according to US measurement of the Abdominal Circumference (AC) centile performed every 2 weeks: 80/100 if AC greater than or equal to75th, 100/140 if AC < 75th. Therapy was tailored to mean fasting (FG) and postprandial glycemia (PPG). Results: Globally, 229 women completed the study, 78 in C, 151 in M. Use of insulin was 16.7% in C, 30.4% in M (total groups), significantly more frequent in M than in C (59.7% vs 15.4%) when considering only women with AC >= 75th c. Mean metabolic data were similar in the 2 groups, but in M a tightly-optimized subgroup, resulting from the lowering of GT due to AC >= 75th, coexisted with a less-controlled one, whose higher GT was justified by AC < 75th. Pregnancy outcome was better in M, with lower (p < 0.05*) rate of LGA* (7.9% vs 17.9%), SGA (6.0% vs 9.0%) and Macrosomia* (3.3% vs 11.5%). Conclusions: Our data show the value of a flexible US-based approach to the treatment of GDM. This model does not necessarily involve a generalized aggressive treatment, allowing to concentrate therapeutical efforts on a small subgroup of women showing indirect evidence of fetal hyperinsulinization. Such a selective approach allowed to obtain a near-normalization of fetal growth, with clear advantages on global pregnancy outcome.