Impact of Carbohydrate Counting Method during Pregnancy in Women with Pregestational Diabetes Mellitus: A Controlled Clinical Trial.

Objective:  To evaluate the effect of the carbohydrate counting method (CCM) on glycemic control, maternal, and perinatal outcomes of pregnant women with pregestational diabetes mellitus (DM).

Methods:  Nonrandomized controlled clinical trial performed with 89 pregnant women who had pregestational DM and received prenatal care in a public hospital in Rio de Janeiro, state of Rio de Janeiro, Brazil, between 2009 and 2014, subdivided into historic control group and intervention group, not simultaneous. The intervention group ( = 51) received nutritional guidance from the carbohydrate counting method (CCM), and the historical control group ( = 38), was guided by the traditional method (TM). The Mann-Whitney test or the Wilcoxon test were used to compare intra- and intergroup outcomes and analysis of variance (ANOVA) for repeated measures, corrected by the Bonferroni post-hoc test, was used to assess postprandial blood glucose.

Results:  Only the CCM group showed a reduction in fasting blood glucose. Postprandial blood glucose decreased in the 2 ( = 0.00) and 3 ( = 0.00) gestational trimester in the CCM group, while in the TM group the reduction occurred only in the 2 trimester ( = 0.015). For perinatal outcomes and hypertensive disorders of pregnancy, there were no differences between groups. Cesarean delivery was performed in 82% of the pregnant women and was associated with hypertensive disorders (gestational hypertension or pre-eclampsia;  = 0.047).

Conclusion:  Both methods of nutritional guidance contributed to the reduction of postprandial glycemia of women and no differences were observed for maternal and perinatal outcomes. However, CCM had a better effect on postprandial glycemia and only this method contributed to reducing fasting blood glucose throughout the intervention.

Rebec Clinical Trials Database:  The present study was registered in the ReBEC Clinical Trials Database (Registro Brasileiro de Ensaios Clínicos, number RBR-524z9n).