Medical management of diabetes in pregnancy

The effect of early feeding on the neonatal blood glucose level at 1-hour of age

Early infant feeding after birth is being promoted, although it is unclear whether this has any effect on carbohydrate metabolism. We planned to measure the capillary glucose at one hour (1 h) of age in a group of infants from non-diabetic pregnancies using the HemoCue B-Glucose system to see if the timing and method of early feeding would influence this result. Seventy-five term infants were studied, 22 of which were breast-fed, 24 bottle fed and 29 not fed during the first hour after birth. The mean whole blood glucose results were 2.34 mmol/l, 2.52 mmol/l and 2.58 mmol/l respectively (P = NS). The first two groups were fed at a median of 22 minutes before sampling. We conclude that the timing and method of early feeding in the newborn have no significant effect on the blood glucose level measured at 1 h of age, and this remains a reliable outcome measure in studies of glucose metabolism in pregnancy.

A comparison of automated fructosamine and HbA1c methods for monitoring diabetes in pregnancy

Two automated methods for measuring fructosamine (Test Plus and the original fructosamine assay) and glycated haemoglobin (Tina-quant immunoassay) were compared to determine which is the best index of blood glucose control during pregnancy. Thirteen women with type 1 diabetes were studied, with four-weekly measurements of HbA1c and fructosamine Test Plus using a Hitachi 911 analyser and fructosamine measured using an Olympus AU800 analyser. HbA1c correlated better (r = 0.573) with mean blood glucose (MBG) concentration than did fructosamine Test Plus (r = 0.347), even after correction for total protein concentration (r = 0.463), while there was no significant correlation with the original fructosamine method (r = 0.201). HbA1c correlated better with fasting/pre-prandial MBG concentrations, whereas fructosamine Test Plus correlated better with post-prandial MBG concentrations. Fructosamine Test Plus decreased with gestational age, and correlated with albumin and total protein concentrations, whereas HbA1c did not change with gestational age. Thus, HbA1c and fructosamine Test Plus were found to be useful in verifying home blood glucose measurements in diabetic pregnancy, with HbA1c being the best predictor of MBG concentration.

Antioxidant status and lipid peroxidation in diabetic pregnancy

Pregnancy in insulin-dependent diabetes mellitus is associated with a greater incidence of fetal abnormality. Animal studies suggest that increased free-radical production and antioxidant depletion may contribute to this risk. The aim of the present study was, therefore, to assess nutritional antioxidant status and lipid peroxidation in diabetic mothers in comparison with a control group. A 7 d dietary history and a food-frequency questionnaire were performed and venous blood collected for biochemical analyses from thirty-eight diabetic mothers and matched control subjects before 12 weeks gestation. Protein intake was significantly greater in diabetic patients (81.4 (SE 14.8) v. 72.7 (SE 15.8) g/d, P = 0.015), while total sugar intake was less (79.5 (SE 13.2) v. 104.8 (SE 28.8) g/d, P < 0.001). There were no significant differences in the intake of the major antioxidant vitamins (retinol, vitamin C or vitamin E) or beta-carotene. However, intakes of a number of other micronutrients (including Se, Zn, Mg, Mn, riboflavin, thiamin, niacin and folate) were greater in diabetic patients. Among the nutritional chain-breaking antioxidants, serum levels of alpha-tocopherol (21.6 (SE 5.7) v. 17.3 (SE 4.7) mumol/, P = 0.0013), beta-carotene (0.27 (SE 0.18) v. 0.14 (SE 0.11) mumol/l, P = 0.003) and lycopene (0.23 (SE 0.17) v. 0.16 (SE 0.13) mumol/l, P = 0.03) were greater in diabetic patients. There was no evidence of greater lipid peroxidation in diabetic patients, and total antioxidant capacity was similar in the two groups. Overall, these results indicate that nutritional antioxidant status is better in this group of diabetic mothers than in control pregnant non-diabetic subjects attending the same maternity hospital.