Antenatal oral glucose tolerance test in women with gestational diabetes mellitus: fasting plasma glucose is the best predictor of both large for-gestational-age newborns and postpartum glucose tolerance.

BACKGROUND: Numerous studies have evaluated the predictors of large-for-gestational-age newborns (LGA) as well as abnormal glucose tolerance (AGT) after delivery in women with gestational diabetes mellitus, one at a time. The present study assesses the ability of glucose values on the antenatal oral glucose tolerance test (OGTT) to predict both outcomes. METHODS: Retrospective analysis of a prospectively collected database. Gestational diabetes was diagnosed with a two-step approach. After delivery, reevaluation was performed using 2006 WHO definition of glucose tolerance. SELECTION CRITERIA: 1) singleton pregnancies; 2) available information on: offspring weight for age, antenatal and follow-up OGTT and additional potential predictors of LGA and AGT. The study included 1241 women. Data were analyzed by multivariate logistic regression and ROC analyses. Logistic regression models were used to calculate adjusted and unadjusted odds ratios and corresponding 95% CI for 1 mmol/L increase in each glucose value (FPG, 1 h, 2 h, 3 h) of the diagnostic 100-g OGTT, associated to the main outcomes LGA and postpartum AGT. RESULTS: Analyzing each glucose value on antenatal OGTT, fasting plasma glucose (FPG) showed the highest OR for both outcomes: LGA (1.537, 95% CI 1.237-1.910) and AGT (2.288, 95% CI 1.869-2.801). On the adjusted analysis the association was attenuated, but FPG continued to be the best predictor for both outcomes. CONCLUSIONS: In women with gestational diabetes mellitus, FPG on the diagnostic OGTT was the glycemic value that best predicted both LGA and after delivery AGT.

Maternal body mass index is a predictor of neonatal hypoglycemia in gestational diabetes mellitus.

CONTEXT: In diabetic pregnancy, neonatal hypoglycemia (NH) is usually attributed to insufficient regulation of maternal glycemic control. Recent data suggest that maternal body mass index (BMI) could have an influence. OBJECTIVE: Our objective was to determine whether an association exists between maternal prepregnancy BMI category and occurrence of NH among infants born to women with gestational diabetes mellitus (GDM). DESIGN AND SETTING: This was a retrospective study including all GDM pregnancies delivered between 1986 and 2006 at a tertiary care center (Hospital de la Santa Creu i Sant Pau, Barcelona). PATIENTS AND OUTCOMES: GDM was diagnosed using universal screening and National Diabetes Data Group criteria. Two thousand ninety-two newborns (1925 singletons, 85% of total GDM offspring) were studied. NH was defined according to Cornblath criteria. In addition to maternal BMI, we considered other variables such as glucose values at diagnosis or third-trimester glycated hemoglobin as potential predictors of NH. We explored whether the association between maternal BMI and NH could be due to intermediate steps such as cesarean section or abnormal birth weight. RESULTS: The rate of NH was 3%. In the bivariate analysis, prepregnancy BMI was higher in the NH group (24.45 vs. 23.19 kg/m(2), P < 0.02). In the logistic regression analysis, prepregnancy BMI of at least 25 kg/m(2) was independently associated with NH whether the analysis included intermediate variables (odds ratio = 2.11; 95% confidence interval = 1.10-4.03) or not (odds ratio = 2.66; 95% confidence interval = 1.44-4.92). CONCLUSIONS: Pregestational BMI should be considered among the predictors of NH in offspring of women with GDM.