Gestational diabetes mellitus: Metabolic and blood glucose parameters in singleton versus twin pregnancies

Objectives: This study compared the frequency, glucose tolerance test results, and parameters of blood glucose control in twin and singleton pregnancies associated with gestational diabetes mellitus and carbohydrate intolerance. Study Design: Twin and singleton pregnancies associated with gestational diabetes mellitus and carbohydrate intolerance were compared as follows: frequency, maternal age, weight, 1-hour screen, glucose tolerance test results, posttreatment blood glucose values, insulin requirement, and insulin dose. Statistical analysis included the χ2 and Student t tests. Results: Gestational diabetes mellitus was increased in twins (7.7% vs 4.1%; P< .05). The maternal weight at first visit was significantly less, and the 3-hour glucose tolerance test value was significantly greater than that for singletons. The other parameters were not different. Conclusions: There is a significant increase in the incidence of gestational diabetes mellitus and disturbance of the 3-hour glucose tolerance test in twin pregnancies. However, insulin requirements were not different, suggesting a mild disturbance of carbohydrate tolerance that was effectively managed by the strategies used to achieve blood glucose control in singletons. (Am J Obstet Gynecol 1999;181:912-4.)