Anneloes Kerssen

Aims/hypothesis Pregnancies of women with type 1 diabetes mellitus are associated with maternal and perinatal complications. These complication rates remain elevated despite achievement of the treatment goals described in the widely used guidelines of the American Diabetes Association (i.e. HbA₁c level ≤7.0%). Against this background, we sought to answer two questions: (1) are HbA₁c levels within 1% above normal appropriate in pregnant women with type 1 diabetes or should treatment be aimed at normal HbA₁c levels; and (2) how many self-monitored blood glucose (SMBG) levels are needed per day to obtain an adequate image of glycaemic control in pregnant women with type 1 diabetes? Materials and methods We asked 43 pregnant women with type 1 diabetes to use the Continuous Glucose Monitoring System (CGMS) once in each trimester of pregnancy, while continuing their SMBG measurements. Glucose levels measured with the CGMS were compared between patients with HbA₁c levels of 4.0–6.0%, 6.0–7.0% and >7.0%. Self-monitored glucose levels and those measured with CGMS were compared between patients with four or five, six to nine and ten or more SMBG determinations daily. Results In patients with HbA₁c levels ≤6.0%, the glucose levels obtained by CGMS were significantly better than in patients with HbA₁c levels >6.0%. In women with HbA₁c levels 6.0–7.0% and >7.0%, these levels did not differ. The detection rate of hyper- and hypoglycaemic episodes was significantly higher in patients with ten or more SMBG determinations daily than in patients with fewer than ten. Conclusions/interpretation Treatment of diabetes in pregnant women should be aimed at achieving HbA₁c levels within the normal range, i.e. ≤6.0%. A minimum of ten SMBG determinations daily is necessary to obtain adequate information of all daily glucose fluctuations.

Background: In pregnant women with type 1 diabetes tight glycemic control reduces perinatal complications. Intensive observation of glucose profiles is essential in the achievement of tight glycemic control. The recent availability of the Continuous Glucose Monitoring System (CGMS®, Minimed, Sylmar, CA) creates the opportunity to obtain more complete glucose profiles. This study was aimed at evaluating the accuracy of the CGMS in pregnant women with type 1 diabetes. Methods: Five pregnant women with type 1 diabetes were asked to use two CGMS devices simultaneously. The simultaneously measured glucose levels were analyzed using the Pearson correlation, the mean absolute difference, and Bland–Altman analysis. Second, the percentage of concordance of paired data in the hypoglycemic, normoglycemic, or hyperglycemic range was calculated. Results: The correlation coefficient between simultaneously measured data was 0.94 (P < 0.001). The mean absolute difference was 1.1 ± 0.8 mmol/L. Bland–Altman analysis shows that 95% of the data pairs have a difference ≤1.74 mmol/L. Almost 80% of the data pairs could be classified in the same glucose range. In 81% of the non-concordant pairs, one glucose value was classified in the hypoglycemic range and one in the normoglycemic range. Conclusions: This study shows that the reproducibility of the CGMS in pregnant women with type 1 diabetes is adequate. This indicates that the CGMS is a useful tool in the management of type 1 diabetes in pregnant women. However, the CGMS should only be used as a supplementary method of daily glucose level measurement as a small degree of error, mainly in the hypoglycemic range, is present.

Aims/hypothesis The aim of this study was to establish the value of maternal HbA₁c levels and older sibling birthweight as predictors of birthweight and macrosomia in the offspring of women with type 1 diabetes. Subjects and methods A total of 214 pregnancies of 107 women with type 1 diabetes were studied. Regression analysis was performed to test the predictive value of the birthweight of the first-born infant, HbA₁c levels, maternal BMI, maternal age and time between subsequent births on the birthweight of the second-born infant. Birthweights were corrected for sex and gestational age. The percentages of first- and second-born infants with macrosomia (weight >90th centile) were calculated and compared. Results Only the birthweight of earlier born infants was significantly related to that of second-born infants (p1c levels during pregnancy. It may, therefore, be used to identify patients at risk of giving birth to a macrosomic infant. Daily home monitoring of glucose levels, rather than HbA₁c levels, should be used for assessment of maternal glycaemia during pregnancy.