Gestational diabetes mellitus. Is further improvement necessary?

The maternal antepartum, intrapartum, and neonatal characteristics of 158 patients with gestational diabetes mellitus (GDM) attending a large teaching hospital between 1979 and 1983 were described and compared with a matched nondiabetic control group. The primary cesarean section rate in patients with GDM (18%) was significantly greater than in the control group (11%, P less than 0.04). Neonatal macrosomia, as reflected in mean birthweight (P less than 0.04), the number of neonates weighing greater than 4 kg (P less than 0.05) and large-for-gestational-age infants (P less than 0.05), and the birthweight adjusted for gestational age (K-score, P less than 0.01) was significantly increased in the diabetic group. The characteristics of patients with GDM treated with diet alone and diet and insulin together were examined. The insulin-therapy group was characterized by more patients older than 25 yr (P less than 0.01) and a higher mean birthweight (3743 +/- 677 g) (P less than 0.02) than the diet-alone group. This may reflect an increased magnitude of glucose intolerance in the insulin-treated group. Obese patients with GDM delivered heavier neonates than the nonobese patients with GDM (P less than 0.01). Although there was no difference between the groups, perinatal mortality was present in this study. These data indicate that the major perinatal morbidity in GDM included increased cesarean section for fetal macrosomia. Early diagnosis with strict diagnostic criteria and rigid antenatal surveillance may result in further improvements in outcome.

Diagnosis of gestational diabetes in early pregnancy.

OBJECTIVE: To determine whether glucose intolerance can be identified early in gestation in a high-risk population so that early intervention can be planned to prevent associated morbidity. RESEARCH DESIGN AND METHODS: After appropriate dietary preparation, patients with a high risk for gestational diabetes underwent a 50-g oral glucose screening test during fasting. Patients were tested on enrollment and every 10 wk until delivery. Those with a 1-h plasma glucose value of greater than or equal to 7.5 mM underwent a 100-g oral glucose tolerance test. Gestational diabetes was based on either a markedly abnormal 50-g screening test or abnormal 100-g oral glucose tolerance test. RESULTS: Ten of 15 (66%) patients who developed gestational diabetes were diagnosed during the first half of the pregnancy. Six were diagnosed in the first trimester. If the definition of an abnormal 1-h plasma glucose value was lowered from 7.5 to 7.2 mM, an additional 2 patients could have been identified in the first trimester with an improvement in sensitivity from 70 to 91% with only a slight drop in specificity (from 91 to 88%). Diagnosis of gestational diabetes was not enhanced by measuring plasma insulin concentrations or insulin-glucose molar ratios. CONCLUSIONS: The diagnosis of gestational diabetes in a high-risk population can be made in the first half of pregnancy. Early diagnosis should permit evaluation of intervention strategies, which may result in improved perinatal outcome.

Maternal obesity as a risk factor in gestational diabetes.

Maternal obesity has been associated with both gestational diabetes mellitus (GDM) and neonatal macrosomia. Most studies of obesity in pregnancy have demonstrated an increased risk for GDM. However, the contribution of obesity as an added risk in GDM has not been examined. The purpose of this study was to examine the contribution of obesity as a risk factor to perinatal morbidity in gestationally diabetic women by comparing the maternal and neonatal outcome in obese and nonobese gestationally diabetic women. From 1979 to 1983, the maternal, intrapartum, and neonatal characteristics of all prepartum gravid patients with GDM were examined. Of the 158 patients with documented GDM, 62 (39%) were obese (weight greater than 90 kg). There was no difference in maternal age (obese 29.3 +/- 5.4 years, nonobese 28.7 +/- 6.5 years) parity, or prepartum risk score between the obese and nonobese patients. The incidence of prematurity, pre-eclampsia, fetal distress, and primary cesarean sections were not different between the groups. There were no differences in Apgar scores, gestational age, or perinatal morbidity. However, the obese patients delivered heavier neonates expressed as mean birthweight (obese 3667 +/- 682 gms, nonobese 3331 +/- 750 gms. P less than .01), the number of macrosomic (greater than 4 kg) neonates (obese 37%, nonobese 14%, P less than .001) and K-score, (obese 0.8 +/- 1, nonobese 0.4 +/- 9, P less than .05). These data indicate that obese patients with GDM have an increased risk of neonatal macrosomia.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased fetal movements with sustained maternal hyperglycemia using the glucose clamp technique.

The purpose of this study was to evaluate the effect of sustained maternal hyperglycemia (120 mg/dl) on fetal activity. The glucose infusion study group was comprised of nine healthy gravidas between 36 and 40 weeks' gestation, and six patients served as controls. The protocol design included an overnight fast for all patients. Fetal movements were evaluated by external fetal monitoring. A 2-hour preinfusion evaluation of fetal activity served as the baseline control for each patient studied. Study patients then received a glucose infusion by a glucose clamp technique to maintain a sustained hyperglycemia of 120 mg/dl for 3 hours. After the glucose infusion, fetal movements were observed for 1 hour. Control patients received a saline infusion for 2 hours after a 2-hour baseline evaluation. Maternal hyperglycemia was associated with a significant decrease of fetal movements greater than 1 second duration during the first hour of glucose infusion. Fetal movements returned to baseline during the second and third hours of glucose infusion. Saline infusion was not associated with a decrease in fetal activity. We conclude that sustained maternal hyperglycemia is associated with a transient decrease in fetal movement during the first hour of glucose infusion followed by a return to the control (preinfusion) level of fetal activity. These data may have implications in the study of fetal behavior in diabetes mellitus.