Diagnostic protocol for gestational diabetes mellitus (GDM) (IADPSG/ADA, 2011): influence on the occurrence of GDM and mild gestational hyperglycemia (MGH) and on the perinatal outcomes.

BACKGROUND: In August 2011, the Specialized Center for Diabetes and Pregnancy of the Botucatu Medical School/Unesp adopted a new diagnostic protocol for gestational diabetes mellitus, recommended by the American Diabetes Association and the International Association of the Diabetes and Pregnancy Study Group. The glycemic profile was evaluated using the 75-g oral glucose tolerance test (OGTT) used to diagnose mild gestational hyperglycemia, recognized and treated in our department as gestational diabetes mellitus. The cost-effectiveness of the new guidelines and the continued need for the evaluation of the glycemic profile, as part of our Service protocol, are controversial and require further investigation. We aimed to assess the impact of the new guidelines on the evaluation of mild gestational hyperglycemia and gestational diabetes mellitus, the incidence of adverse perinatal outcomes, and the association between the 75-g OGTT and the glycemic profile for the diagnosis of mild gestational hyperglycemia. METHODS: This cross-sectional study was performed identifying a convenience sample of pregnant women and their newborns. The women used our Service for diagnostic procedures, prenatal care and delivery, both before (January 2008 to August 14, 2011) and after (August 15, 2011 to December 2014) the protocol modification. The following variables were compared, following stratification according to diagnostic protocol: prevalence of gestational diabetes mellitus and mild gestational hyperglycemia, newborns large for gestational age, macrosomia, first cesarean delivery, and newborn hospital stay. Statistical analysis was performed using Poisson regression, the Student's t test, the Chi square or Fisher's exact test and risk estimate. The statistical significance threshold was set at 95% (p < 0.05). RESULTS: The new protocol resulted in an 85% increase in the number of women with GDM, but failed to identify 17.3% of pregnant women classified as having mild gestational hyperglycemia, despite a normal 75-g OGTT. The new guidelines did not affect perinatal outcome. CONCLUSIONS: These results support the validity of maintaining the glycemic profile as part of the diagnostic protocol at our hospital. Large multicenter studies with an adequate sample size are required for conclusive evidence on the cost-effectiveness of the new protocol.

Waist circumference in predicting gestational diabetes mellitus.

BACKGROUND: To evaluate waist circumference (WC) measured at 20-24 weeks of gestation as a predictor of gestational diabetes mellitus (GDM). METHODS: This cross-sectional study included 240 women at 20-24 weeks of gestation. At enrollment, WC was measured, and both prepregnancy and gestational body mass index (BMI) were estimated. According to the results of 75-g oral glucose tolerance test (OGTT) performed at 24-28 weeks, subjects were allocated into two groups, non-GDM and GDM. WC sensitivity and specificity, and odds ratios (OR) and 95% confidence intervals for BMI and WC were estimated, and a receiver operating characteristics curve was generated. RESULTS: Of the 240 pregnant women enrolled, 31 (13%) had GDM. Prepregnancy BMI (OR = 4.21), gestational BMI (OR = 3.17) and WC at 20-24 weeks (OR = 4.02) correlated with GDM risk. At 20-24 weeks, a WC of 85.5-88.5 cm was the optimal cutoff point for predicting GDM (Sens/Spec balance between 87.1/41.1% and 77.4/56.9%). CONCLUSION: At 20-24 weeks of gestation, WC values in the range of 86-88 cm showed to be a good performance in predicting GDM.

Heat shock protein production and immunity and altered fetal development in diabetic pregnant rats.

We evaluated associations between the concentrations of heat shock proteins (hsp60 and hsp70) and their respective antibodies, alterations in maternal reproductive performance, and fetal malformations in pregnant rats with hyperglycemia. Mild diabetes (MD) or severe diabetes (SD) was induced in Sprague-Dawley rats prior to mating; non-treated non-diabetic rats (ND) served as controls. On day 21 of pregnancy, maternal blood was analyzed for hsp60 and hsp70 and their antibodies; and fetuses were weighed and analyzed for congenital malformations. Hsp and anti-hsp levels were correlated with blood glucose levels during gestation. There was a positive correlation between hsp60 and hsp70 levels and the total number of malformations (R = 0.5908, P = 0.0024; R = 0.4877, P = 0.0134, respectively) and the number of malformations per fetus (R = 0.6103, P = 0.0015; R = 0.4875, P = 0.0134, respectively). The anti-hsp60 IgG concentration was correlated with the number of malformations per fetus (R = 0.3887, P = 0.0451) and the anti-hsp70 IgG level correlated with the total number of malformations (R = 0.3999, P = 0.0387). Moreover, both hsp and anti-hsp antibodies showed negative correlations with fetal weight. The results suggest that there is a relationship between hsp60 and hsp70 levels and their respective antibodies and alterations in maternal reproductive performance and impaired fetal development and growth in pregnancies associated with diabetes.

Oxidative stress and diabetes in pregnant rats.

A considerable amount of clinical and experimental evidence now exists suggesting the involvement of free radical-mediated oxidative processes in the pathogenesis of diabetic complications. If the diabetic state is associated with a generalized increase in oxidative stress, it might well be reflected in the alterations in embryonic and fetal development during pregnancy. In the present study, incidence of the malformed fetuses, biochemical parameters and antioxidant system activity of streptozotocin (STZ)-induced diabetic pregnant rats was investigated and the results obtained were compared with those of the control group (non-diabetic). Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. All the females were killed on Day 21 of pregnancy and the fetuses were analyzed. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic dams presented hyperglycemia, hyperlipemia, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased reduced glutathione (GSH), hepatic glycogen and superoxide dismutase (SOD) determinations. There was an increased incidence of skeletal and visceral malformation in fetuses from diabetic rats. Our findings suggest that oxidative stress occurs in the diabetic pregnant state, which might promote maternal homeostasis alterations. These diabetic complications might be a contributory factor to conceptus damage causing embryonic death (abortion/miscarriage) or the appearance of malformations in the fetuses of diabetic dams. Antioxidant treatment of women with diabetes may be important in future attempts to prevent congenital malformations.