Treatment of mild gestational diabetes reduces some, but not all, risks

Treating mild gestational diabetes doesn't improve perinatal mortality or conditions linked to maternal carbohydrate intolerance such as neonatal hypoglycemia, hyperbilirubinemia, hyperinsulinemia, and birth trauma. However, it does seem to reduce the risks for fetal overgrowth, shoulder dystocia, cesarean delivery, and hypertensive disorders.

The findings come from a multicenter, randomized trial involving almost 1,000 women, 24 to 31 weeks pregnant, who were diagnosed with mild gestational diabetes mellitus (ie, abnormal result on a 100-g oral glucose tolerance test but a fasting glucose level <95 mg/dL). Treatment consisted of dietary intervention, self-monitoring of blood glucose, and insulin therapy, if necessary. Researchers observed no significant difference between treatment and control groups in the frequency of a composite outcome, which included stillbirth, perinatal death, hyperbilirubinemia, hypoglycemia, hyperinsulinemia, and birth trauma (32.4% and 37.0%, respectively; P=.14). No perinatal deaths occurred.

Significant reductions, however, were seen with treatment in mean birth weight (3,302 g vs 3,408 g), neonatal fat mass (427 g vs 464 g), frequency of large-for-gestational-age infants (7.1% vs 14.5%), birth weight >4,000 g (5.9% vs 14.3%), shoulder dystocia (1.5% vs 4.0%), and cesarean delivery (26.9% vs 33.8%). Treatment was also associated with reduced rates of preeclampsia and gestational hypertension (combined rates for both conditions, 8.6% vs 13.6%; P=.01).

Landon MB, Spong CY, Thom E, et al. A multicenter, randomized trial of treatment for mild gestational diabetes. N Engl J Med. 2009;361(14):1339-1348.