Prevention of perinatal morbidity by tight metabolic control in gestational diabetes mellitus

In a prospective controlled trial, we studied the effect of tight metabolic control on the outcomes of 102 gestational diabetes mellitus (GDM) pregnancies compared with outcomes of 102 matched nondiabetic control pregnancies. Women with GDM were treated to achieve and maintain a blood glucose concentration of less than 130 mg/dl at 1 h after breakfast. Treatment consisted of a diet low in oligosaccharides and fat and, if necessary, once daily insulin. By the end of gestation, 88 of the 102 women with GDM received insulin at a mean dose of 18 U/day. Duration of insulin therapy ranged from 3 to 32 wk with a median of 11 wk. Perinatal outcome of GDM pregnancies under this management equaled that of control pregnancies. The full spectrum of excess morbidity from GDM was prevented, and normal distribution of birth weight and normal rates of macrosomia, dystrophy, hypoglycemia, hypocalcemia, hyperbilirubinemia, fetal acidosis, and low Apgar scores were achieved. No mortality was observed. In addition to the two main study groups, we also studied a third group of 24 women with GDM whose treatment lasted less than or equal to 5 wk due to late diagnosis. This suboptimally treated group demonstrated a significant (P less than .05) increase of macrosomia and umbilical artery acidosis compared with the well-treated GDM group. The study reported herein demonstrates that excess mortality and morbidity typically observed in GDM can be prevented by early institution of tight metabolic control, which required insulin in 86% of our patients.