The effects of first-trimester diabetes control on the incidence of macrosomia,

Objective: The aim of this study was to explore the association between glycosylated hemoglobin concentrations during pregnancy and macrosomia. Study Design: One hundred thirty-six pregnancies in 120 women with type 1 or type 2 diabetes were studied longitudinally between January 1, 1991, and December 31, 1996. Glycosylated hemoglobin concentration and several maternal variables of mothers of neonates who were large for gestational age were compared with those of neonates who were appropriate for gestational age. Receiver-operator characteristic curves and regression analyses were used to determine a threshold related to macrosomia and to assess its predictive value. Results: Glycosylated hemoglobin concentrations throughout pregnancy were higher in mothers of neonates who were large for gestational age (n = 65) than in mothers of neonates who were appropriate for gestational age (n = 71, P< .001). A first-trimester glycosylated hemoglobin concentration of ≥5.5% (3 SD above the normal mean) was established by receiver-operator characteristic curves as the strongest predictor of macrosomia and yielded an odds ratio of 24 in multiple logistic regression analysis. Conclusion: Macrosomia is determined mainly by first-trimester diabetes control. (Am J Obstet Gynecol 1999;181:202-6.)