A randomized controlled trial using glycemic plus fetal ultrasound parameters versus glycemic parameters to determine insulin therapy in gestational diabetes with fasting hyperglycemia

OBJECTIVE - To compare management based on maternal glycemic criteria with management based on relaxed glycemic criteria and fetal abdominal circumfer ence (AC) measurements in order to select patients for insulin treatment of gestational diabetes mellitus (GDM) with fasting hyperglycemia. RESEARCH DESIGN AND METHODS - in a pilot study, 98 women with fasting plasm a glucose (FPG) concentrations of 105-120 mg/dl were randomized. The standa rd group received insulin treatment. The experimental group received insuli n if the AC, measured monthly, was greater than or equal to 70th percentile and/or if any venous FPG measurement was > 120 mg/dl. Power was projected to detect a 250-g difference in birth weights. RESULTS - Gestational ages, maternal glycemia, and AC percentiles were simi lar at randomization. After initiation of protocol, venous FPG (P = 0.003) and capillary blood glucose levels (P = 0.049) were significantly lower in the standard group. Birth weights (3,271 +/- 458 vs 3,369 +/- 461 g), frequ encies of birth weights > 90th percentile (6.3 vs 8.3%), and neonatal morbi dity (25 vs. 25%) did not differ significantly between the standard and exp erimental groups, respectively. The cesarean delivery rate was significantl y lower (14.6 vs 33.3%, P = 0.03) in the standard groups this difference wa s not explained by birth weights. In the experimental group, infants of wom en who did not receive insulin had lower birth weights than infants of moth ers treated with insulin (3,180 +/- 425 vs. 3,482 +/- 451 g, P = 0.03). CONCLUSIONS - in women with GDM and fasting hyperglycemia, glucose plus fet al AC measurements identified pregnancies at low risk for macrosomia and re sulted in the avoidance of insulin therapy in 38% of patients without incre asing rates of neonatal morbidity.