Gestational diabetes and preterm labour: Is glycaemic control a contributing factor?

Objectives: (1) to evaluate the incidence of preterm delivery in patients with gestational diabetes mellitus; (2) to determine the association between glycaemic control and preterm delivery in these patients. Study design: (1) The incidence of spontaneous preterm singleton deliveries was determined in 550 intensively-treated patients with gestational diabetes mellitus. A total of 14 552 consecutive patients without gestational diabetes mellitus who delivered during the same interval served as a control population; (2) Glycaemic profiles (i.e., mean blood glucose, percent of hypoglycaemic [<60 mg/dl] and hyperglycaemic [>120 mg/dl] episodes) were compared in 34 patients with gestational diabetes mellitus who delivered preterm, and 68 matched controls with gestational diabetes mellitus who delivered at term. Results: (1) The incidence of preterm delivery in gestational diabetics was similar to that found in the non-diabetic population (6.2% vs. 6.5%, respectively, P=0.82; confidence limits: 0.65, 1.36); (2) women with gestational diabetes mellitus who delivered at term, or preterm had similar glycaemic profiles for both the entire treatment period and the week preceding delivery. Conclusions: (1) There is no increased risk for preterm delivery in intensively-treated gestational diabetes mellitus patients; (2) In a population such as this women with gestational diabetes mellitus who deliver preterm cannot be characterised by their glycaemic profile.